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Find video protocols related to scientific articles indexed in Pubmed.
HMG-coenzyme A reductase inhibition, type 2 diabetes, and bodyweight: evidence from genetic analysis and randomised trials.
Daniel I Swerdlow, David Preiss, Karoline B Kuchenbaecker, Michael V Holmes, Jorgen E L Engmann, Tina Shah, Reecha Sofat, Stefan Stender, Paul C D Johnson, Robert A Scott, Maarten Leusink, Niek Verweij, Stephen J Sharp, Yiran Guo, Claudia Giambartolomei, Christina Chung, Anne Peasey, Antoinette Amuzu, KaWah Li, Jutta Palmen, Philip Howard, Jackie A Cooper, Fotios Drenos, Yun R Li, Gordon Lowe, John Gallacher, Marlene C W Stewart, Ioanna Tzoulaki, Sarah G Buxbaum, Daphne L van der A, Nita G Forouhi, N Charlotte Onland-Moret, Yvonne T van der Schouw, Renate B Schnabel, Jaroslav A Hubacek, Růžena Kubinova, Miglė Bacevičienė, Abdonas Tamosiunas, Andrzej Pająk, Romanvan Topor-Madry, Urszula Stepaniak, Sofia Malyutina, Damiano Baldassarre, Bengt Sennblad, Elena Tremoli, Ulf de Faire, Fabrizio Veglia, Ian Ford, J Wouter Jukema, Rudi G J Westendorp, Gert Jan de Borst, Pim A de Jong, Ale Algra, Wilko Spiering, Anke H Maitland-van der Zee, Olaf H Klungel, Anthonius de Boer, Pieter A Doevendans, Charles B Eaton, Jennifer G Robinson, David Duggan, , John Kjekshus, John R Downs, Antonio M Gotto, Anthony C Keech, Roberto Marchioli, Gianni Tognoni, Peter S Sever, Neil R Poulter, David D Waters, Terje R Pedersen, Pierre Amarenco, Haruo Nakamura, John J V McMurray, James D Lewsey, Daniel I Chasman, Paul M Ridker, Aldo P Maggioni, Luigi Tavazzi, Kausik K Ray, Sreenivasa Rao Kondapally Seshasai, JoAnn E Manson, Jackie F Price, Peter H Whincup, Richard W Morris, Debbie A Lawlor, George Davey Smith, Yoav Ben-Shlomo, Pamela J Schreiner, Myriam Fornage, David S Siscovick, Mary Cushman, Meena Kumari, Nick J Wareham, W M Monique Verschuren, Susan Redline, Sanjay R Patel, John C Whittaker, Anders Hamsten, Joseph A Delaney, Caroline Dale, Tom R Gaunt, Andrew Wong, Diana Kuh, Rebecca Hardy, Sekar Kathiresan, Berta A Castillo, Pim van der Harst, Eric J Brunner, Anne Tybjaerg-Hansen, Michael G Marmot, Ronald M Krauss, Michael Tsai, Josef Coresh, Ronald C Hoogeveen, Bruce M Psaty, Leslie A Lange, Hakon Hakonarson, Frank Dudbridge, Steve E Humphries, Philippa J Talmud, Mika Kivimäki, Nicholas J Timpson, Claudia Langenberg, Folkert W Asselbergs, Mikhail Voevoda, Martin Bobak, Hynek Pikhart, James G Wilson, Alex P Reiner, Brendan J Keating, Aroon D Hingorani, Naveed Sattar.
Lancet
PUBLISHED: 09-29-2014
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Statins increase the risk of new-onset type 2 diabetes mellitus. We aimed to assess whether this increase in risk is a consequence of inhibition of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), the intended drug target.
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Testing for non-linear causal effects using a binary genotype in a Mendelian randomization study: application to alcohol and cardiovascular traits.
Int J Epidemiol
PUBLISHED: 09-05-2014
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Mendelian randomization studies have so far restricted attention to linear associations relating the genetic instrument to the exposure, and the exposure to the outcome. In some cases, however, observational data suggest a non-linear association between exposure and outcome. For example, alcohol consumption is consistently reported as having a U-shaped association with cardiovascular events. In principle, Mendelian randomization could address concerns that the apparent protective effect of light-to-moderate drinking might reflect 'sick-quitters' and confounding.
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Concordance of genetic risk across migraine subgroups: Impact on current and future genetic association studies.
Cephalalgia
PUBLISHED: 09-01-2014
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There has been intensive debate whether migraine with aura (MA) and migraine without aura (MO) should be considered distinct subtypes or part of the same disease spectrum. There is also discussion to what extent migraine cases collected in specialised headache clinics differ from cases from population cohorts, and how female cases differ from male cases with respect to their migraine. To assess the genetic overlap between these migraine subgroups, we examined genome-wide association (GWA) results from analysis of 23,285 migraine cases and 95,425 population-matched controls.
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Assessment of body composition in Indian adults: comparison between dual-energy X-ray absorptiometry and isotope dilution technique.
Br. J. Nutr.
PUBLISHED: 08-11-2014
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Dual-energy X-ray absorptiometry (DXA) and isotope dilution technique have been used as reference methods to validate the estimates of body composition by simple field techniques; however, very few studies have compared these two methods. We compared the estimates of body composition by DXA and isotope dilution (18O) technique in apparently healthy Indian men and women (aged 19-70 years, n 152, 48 % men) with a wide range of BMI (14-40 kg/m2). Isotopic enrichment was assessed by isotope ratio mass spectroscopy. The agreement between the estimates of body composition measured by the two techniques was assessed by the Bland-Altman method. The mean age and BMI were 37 (sd 15) years and 23·3 (sd 5·1) kg/m2, respectively, for men and 37 (sd 14) years and 24·1 (sd 5·8) kg/m2, respectively, for women. The estimates of fat-free mass were higher by about 7 (95 % CI 6, 9) %, those of fat mass were lower by about 21 (95 % CI - 18, - 23) %, and those of body fat percentage (BF%) were lower by about 7·4 (95 % CI - 8·2, - 6·6) % as obtained by DXA compared with the isotope dilution technique. The Bland-Altman analysis showed wide limits of agreement that indicated poor agreement between the methods. The bias in the estimates of BF% was higher at the lower values of BF%. Thus, the two commonly used reference methods showed substantial differences in the estimates of body composition with wide limits of agreement. As the estimates of body composition are method-dependent, the two methods cannot be used interchangeably.
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Novel approach identifies SNPs in SLC2A10 and KCNK9 with evidence for parent-of-origin effect on body mass index.
PLoS Genet.
PUBLISHED: 07-01-2014
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The phenotypic effect of some single nucleotide polymorphisms (SNPs) depends on their parental origin. We present a novel approach to detect parent-of-origin effects (POEs) in genome-wide genotype data of unrelated individuals. The method exploits increased phenotypic variance in the heterozygous genotype group relative to the homozygous groups. We applied the method to >56,000 unrelated individuals to search for POEs influencing body mass index (BMI). Six lead SNPs were carried forward for replication in five family-based studies (of ?4,000 trios). Two SNPs replicated: the paternal rs2471083-C allele (located near the imprinted KCNK9 gene) and the paternal rs3091869-T allele (located near the SLC2A10 gene) increased BMI equally (beta?=?0.11 (SD), P<0.0027) compared to the respective maternal alleles. Real-time PCR experiments of lymphoblastoid cell lines from the CEPH families showed that expression of both genes was dependent on parental origin of the SNPs alleles (P<0.01). Our scheme opens new opportunities to exploit GWAS data of unrelated individuals to identify POEs and demonstrates that they play an important role in adult obesity.
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Effects of BMI, fat mass, and lean mass on asthma in childhood: a Mendelian randomization study.
PLoS Med.
PUBLISHED: 07-01-2014
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Observational studies have reported associations between body mass index (BMI) and asthma, but confounding and reverse causality remain plausible explanations. We aim to investigate evidence for a causal effect of BMI on asthma using a Mendelian randomization approach.
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Resolving the effects of maternal and offspring genotype on dyadic outcomes in genome wide complex trait analysis ("M-GCTA").
Behav. Genet.
PUBLISHED: 06-10-2014
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Genome wide complex trait analysis (GCTA) is extended to include environmental effects of the maternal genotype on offspring phenotype ("maternal effects", M-GCTA). The model includes parameters for the direct effects of the offspring genotype, maternal effects and the covariance between direct and maternal effects. Analysis of simulated data, conducted in OpenMx, confirmed that model parameters could be recovered by full information maximum likelihood (FIML) and evaluated the biases that arise in conventional GCTA when indirect genetic effects are ignored. Estimates derived from FIML in OpenMx showed very close agreement to those obtained by restricted maximum likelihood using the published algorithm for GCTA. The method was also applied to illustrative perinatal phenotypes from ~4,000 mother-offspring pairs from the Avon Longitudinal Study of Parents and Children. The relative merits of extended GCTA in contrast to quantitative genetic approaches based on analyzing the phenotypic covariance structure of kinships are considered.
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The many weak instruments problem and Mendelian randomization.
Stat Med
PUBLISHED: 04-14-2014
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Instrumental variable estimates of causal effects can be biased when using many instruments that are only weakly associated with the exposure. We describe several techniques to reduce this bias and estimate corrected standard errors. We present our findings using a simulation study and an empirical application. For the latter, we estimate the effect of height on lung function, using genetic variants as instruments for height. Our simulation study demonstrates that, using many weak individual variants, two-stage least squares (2SLS) is biased, whereas the limited information maximum likelihood (LIML) and the continuously updating estimator (CUE) are unbiased and have accurate rejection frequencies when standard errors are corrected for the presence of many weak instruments. Our illustrative empirical example uses data on 3631 children from England. We used 180 genetic variants as instruments and compared conventional ordinary least squares estimates with results for the 2SLS, LIML, and CUE instrumental variable estimators using the individual height variants. We further compare these with instrumental variable estimates using an unweighted or weighted allele score as single instruments. In conclusion, the allele scores and CUE gave consistent estimates of the causal effect. In our empirical example, estimates using the allele score were more efficient. CUE with corrected standard errors, however, provides a useful additional statistical tool in applications with many weak instruments. The CUE may be preferred over an allele score if the population weights for the allele score are unknown or when the causal effects of multiple risk factors are estimated jointly. © 2014 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd.
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Parental obesity and risk of autism spectrum disorder.
Pediatrics
PUBLISHED: 04-07-2014
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The objective of the study was to investigate the associations among maternal prepregnancy BMI, paternal BMI, and the risk of autism spectrum disorders (ASDs) in children.
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Harmonization of Neuroticism and Extraversion phenotypes across inventories and cohorts in the Genetics of Personality Consortium: an application of Item Response Theory.
Behav. Genet.
PUBLISHED: 03-20-2014
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Mega- or meta-analytic studies (e.g. genome-wide association studies) are increasingly used in behavior genetics. An issue in such studies is that phenotypes are often measured by different instruments across study cohorts, requiring harmonization of measures so that more powerful fixed effect meta-analyses can be employed. Within the Genetics of Personality Consortium, we demonstrate for two clinically relevant personality traits, Neuroticism and Extraversion, how Item-Response Theory (IRT) can be applied to map item data from different inventories to the same underlying constructs. Personality item data were analyzed in >160,000 individuals from 23 cohorts across Europe, USA and Australia in which Neuroticism and Extraversion were assessed by nine different personality inventories. Results showed that harmonization was very successful for most personality inventories and moderately successful for some. Neuroticism and Extraversion inventories were largely measurement invariant across cohorts, in particular when comparing cohorts from countries where the same language is spoken. The IRT-based scores for Neuroticism and Extraversion were heritable (48 and 49 %, respectively, based on a meta-analysis of six twin cohorts, total N = 29,496 and 29,501 twin pairs, respectively) with a significant part of the heritability due to non-additive genetic factors. For Extraversion, these genetic factors qualitatively differ across sexes. We showed that our IRT method can lead to a large increase in sample size and therefore statistical power. The IRT approach may be applied to any mega- or meta-analytic study in which item-based behavioral measures need to be harmonized.
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A rare variant in APOC3 is associated with plasma triglyceride and VLDL levels in Europeans.
Nat Commun
PUBLISHED: 03-07-2014
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The analysis of rich catalogues of genetic variation from population-based sequencing provides an opportunity to screen for functional effects. Here we report a rare variant in APOC3 (rs138326449-A, minor allele frequency ~0.25% (UK)) associated with plasma triglyceride (TG) levels (-1.43 s.d. (s.e.=0.27 per minor allele (P-value=8.0 × 10(-8))) discovered in 3,202 individuals with low read-depth, whole-genome sequence. We replicate this in 12,831 participants from five additional samples of Northern and Southern European origin (-1.0 s.d. (s.e.=0.173), P-value=7.32 × 10(-9)). This is consistent with an effect between 0.5 and 1.5 mmol l(-1) dependent on population. We show that a single predicted splice donor variant is responsible for association signals and is independent of known common variants. Analyses suggest an independent relationship between rs138326449 and high-density lipoprotein (HDL) levels. This represents one of the first examples of a rare, large effect variant identified from whole-genome sequencing at a population scale.
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Interplay of genetic risk (CHRNA5) and environmental risk (partner smoking) on cigarette smoking reduction.
Drug Alcohol Depend
PUBLISHED: 03-04-2014
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This study tests whether the genetic predictor (CHRNA5 nicotine receptor gene variants) and an environmental risk factor (partner smoking) interact in the prediction of smoking reduction.
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Elevated circulating Sclerostin concentrations in individuals with high bone mass, with and without LRP5 mutations.
J. Clin. Endocrinol. Metab.
PUBLISHED: 02-25-2014
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The role and importance of circulating sclerostin is poorly understood. High bone mass (HBM) caused by activating LRP5 mutations has been reported to be associated with increased plasma sclerostin concentrations; whether the same applies to HBM due to other causes is unknown.
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Variability in the common genetic architecture of social-communication spectrum phenotypes during childhood and adolescence.
Mol Autism
PUBLISHED: 02-04-2014
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Social-communication abilities are heritable traits, and their impairments overlap with the autism continuum. To characterise the genetic architecture of social-communication difficulties developmentally and identify genetic links with the autistic dimension, we conducted a genome-wide screen of social-communication problems at multiple time-points during childhood and adolescence.
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Mendelian randomization in health research: using appropriate genetic variants and avoiding biased estimates.
Econ Hum Biol
PUBLISHED: 01-07-2014
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Mendelian randomization methods, which use genetic variants as instrumental variables for exposures of interest to overcome problems of confounding and reverse causality, are becoming widespread for assessing causal relationships in epidemiological studies. The main purpose of this paper is to demonstrate how results can be biased if researchers select genetic variants on the basis of their association with the exposure in their own dataset, as often happens in candidate gene analyses. This can lead to estimates that indicate apparent "causal" relationships, despite there being no true effect of the exposure. In addition, we discuss the potential bias in estimates of magnitudes of effect from Mendelian randomization analyses when the measured exposure is a poor proxy for the true underlying exposure. We illustrate these points with specific reference to tobacco research.
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The association of early childhood cognitive development and behavioural difficulties with pre-adolescent problematic eating attitudes.
PLoS ONE
PUBLISHED: 01-01-2014
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Few studies have prospectively investigated associations of child cognitive ability and behavioural difficulties with later eating attitudes. We investigated associations of intelligence quotient (IQ), academic performance and behavioural difficulties at 6.5 years with eating attitudes five years later.
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Association of common genetic variants with lipid traits in the Indian population.
PLoS ONE
PUBLISHED: 01-01-2014
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Genome-wide association studies (GWAS) have been instrumental in identifying novel genetic variants associated with altered plasma lipid levels. However, these quantitative trait loci have not been tested in the Indian population, where there is a poorly understood and growing burden of cardiometabolic disorders. We present the association of six single nucleotide polymorphisms in 1671 sib pairs (3342 subjects) with four lipid traits: total cholesterol, triglycerides, high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C). We also investigated the interaction effects of gender, location, fat intake and physical activity. Each copy of the risk allele of rs964184 at APOA1 was associated with 1.06 mmol/l increase in triglycerides (SE = 0.049; p = 0.006), rs3764261 at CETP with 1.02 mmol/l increase in both total cholesterol (SE = 0.042; p = 0.017) and HDL-C (SE = 0.041; p = 0.008), rs646776 at CELSR2-PSRC1-SORT1 with 0.96 mmol/l decrease in cholesterol (SE = 0.043; p = 0.0003) and 0.15 mmol/l decrease in LDL-C levels (SE = 0.043; p = 0.0003) and rs2954029 at TRIB1 with 1.02 mmol/l increase in HDL-C (SE = 0.039; p = 0.047). A combined risk score of APOA1 and CETP loci predicted an increase of 1.25 mmol/l in HDL-C level (SE = 0.312; p = 0.0007). Urban location and sex had strong interaction effects on the genetic association of most of the studied loci with lipid traits. To conclude, we validated four genetic variants (identified by GWAS in western populations) associated with lipid traits in the Indian population. The interaction effects found here may explain the sex-specific differences in lipid levels and their heritability. Urbanization appears to influence the nature of the association with GWAS lipid loci in this population. However, these findings will require replication in other Indian populations.
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Comparison of father-offspring and mother-offspring associations of cardiovascular risk factors: family linkage within the population-based HUNT Study, Norway.
Int J Epidemiol
PUBLISHED: 12-23-2013
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Cardiovascular risk factors are transmitted from parents to offspring; however, the relative contributions of fathers and mothers remain unclear. If maternal exposures during pregnancy influence offspring through the intrauterine environment, associations between mothers and offspring are expected to be stronger than between fathers and offspring. In this family linkage study we compared father-offspring and mother-offspring associations of several cardiovascular risk factors.
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Effects of Promoting Longer Term and Exclusive Breastfeeding on Cardiometabolic Risk Factors at Age 11.5 Years: A Cluster-Randomized, Controlled Trial.
Circulation
PUBLISHED: 12-03-2013
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The duration and exclusivity of breastfeeding in infancy have been inversely associated with future cardiometabolic risk. We investigated the effects of an experimental intervention to promote increased duration of exclusive breastfeeding on cardiometabolic risk factors in childhood.
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Genetic influences on trajectories of systolic blood pressure across childhood and adolescence.
Circ Cardiovasc Genet
PUBLISHED: 11-07-2013
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Background- Blood pressure (BP) tends to increase across childhood and adolescence, but the genetic influences on rates of BP change are not known. Potentially important genetic influences could include genetic variants identified in genome-wide association studies of adults as being associated with BP, height, and body mass index. Understanding the contribution of these genetic variants to changes in BP across childhood and adolescence could yield understanding into the life course development of cardiovascular risk. Methods and Results- Pooling data from 2 cohorts (the Avon Longitudinal Study of Parents and Children [n=7013] and the Western Australian Pregnancy Cohort [n=1459]), we examined the associations of allelic scores of 29 single-nucleotide polymorphisms (SNPs) for adult BP, 180 height SNPs, and 32 body mass index SNPs, with trajectories of systolic BP (SBP) from 6 to 17 years of age, using linear spline multilevel models. The allelic scores of BP and body mass index SNPs were associated with SBP at 6 years of age (per-allele effect sizes, 0.097 mm Hg [SE, 0.039 mm Hg] and 0.107 mm Hg [SE, 0.037 mm Hg]); associations with age-related changes in SBP between 6 and 17 years of age were of small magnitude and imprecisely estimated. The allelic score of height SNPs was only weakly associated with SBP changes. No sex or cohort differences in genetic effects were observed. Conclusions- Allelic scores of BP and body mass index SNPs demonstrated associations with SBP at 6 years of age with a similar magnitude but were not strongly associated with changes in SBP with age between 6 and 17 years. Further work is required to identify variants associated with changes with age in BP.
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Prenatal alcohol exposure and offspring cognition and school performance. A Mendelian randomization natural experiment.
Int J Epidemiol
PUBLISHED: 09-24-2013
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There is substantial debate as to whether moderate alcohol use during pregnancy could have subtle but important effects on offspring, by impairing later cognitive function and thus school performance. The authors aimed to investigate the unconfounded effect of moderately increased prenatal alcohol exposure on cognitive/educational performance.
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Common variants in left/right asymmetry genes and pathways are associated with relative hand skill.
PLoS Genet.
PUBLISHED: 09-01-2013
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Humans display structural and functional asymmetries in brain organization, strikingly with respect to language and handedness. The molecular basis of these asymmetries is unknown. We report a genome-wide association study meta-analysis for a quantitative measure of relative hand skill in individuals with dyslexia [reading disability (RD)] (n = 728). The most strongly associated variant, rs7182874 (P = 8.68 × 10(-9)), is located in PCSK6, further supporting an association we previously reported. We also confirmed the specificity of this association in individuals with RD; the same locus was not associated with relative hand skill in a general population cohort (n = 2,666). As PCSK6 is known to regulate NODAL in the development of left/right (LR) asymmetry in mice, we developed a novel approach to GWAS pathway analysis, using gene-set enrichment to test for an over-representation of highly associated variants within the orthologs of genes whose disruption in mice yields LR asymmetry phenotypes. Four out of 15 LR asymmetry phenotypes showed an over-representation (FDR ? 5%). We replicated three of these phenotypes; situs inversus, heterotaxia, and double outlet right ventricle, in the general population cohort (FDR ? 5%). Our findings lead us to propose that handedness is a polygenic trait controlled in part by the molecular mechanisms that establish LR body asymmetry early in development.
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Development and validation of anthropometric prediction equations for estimation of lean body mass and appendicular lean soft tissue in Indian men and women.
J. Appl. Physiol.
PUBLISHED: 08-15-2013
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Lean body mass (LBM) and muscle mass remain difficult to quantify in large epidemiological studies due to the unavailability of inexpensive methods. We therefore developed anthropometric prediction equations to estimate the LBM and appendicular lean soft tissue (ALST) using dual-energy X-ray absorptiometry (DXA) as a reference method. Healthy volunteers (n = 2,220; 36% women; age 18-79 yr), representing a wide range of body mass index (14-44 kg/m(2)), participated in this study. Their LBM, including ALST, was assessed by DXA along with anthropometric measurements. The sample was divided into prediction (60%) and validation (40%) sets. In the prediction set, a number of prediction models were constructed using DXA-measured LBM and ALST estimates as dependent variables and a combination of anthropometric indices as independent variables. These equations were cross-validated in the validation set. Simple equations using age, height, and weight explained >90% variation in the LBM and ALST in both men and women. Additional variables (hip and limb circumferences and sum of skinfold thicknesses) increased the explained variation by 5-8% in the fully adjusted models predicting LBM and ALST. More complex equations using all of the above anthropometric variables could predict the DXA-measured LBM and ALST accurately, as indicated by low standard error of the estimate (LBM: 1.47 kg and 1.63 kg for men and women, respectively), as well as good agreement by Bland-Altman analyses (Bland JM, Altman D. Lancet 1: 307-310, 1986). These equations could be a valuable tool in large epidemiological studies assessing these body compartments in Indians and other population groups with similar body composition.
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Analysis of self-selection bias in a population-based cohort study of autism spectrum disorders.
Paediatr Perinat Epidemiol
PUBLISHED: 08-08-2013
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This study examined potential self-selection bias in a large pregnancy cohort by comparing exposure-outcome associations from the cohort to similar associations obtained from nationwide registry data. The outcome under study was specialist-confirmed diagnosis of autism spectrum disorders (ASDs).
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Prenatal methylmercury exposure and genetic predisposition to cognitive deficit at age 8 years.
Epidemiology
PUBLISHED: 08-02-2013
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Cognitive consequences at school age associated with prenatal methylmercury (MeHg) exposure may need to take into account nutritional and sociodemographic cofactors as well as relevant genetic polymorphisms.
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Approaches for strengthening causal inference regarding prenatal risk factors for childhood behavioural and psychiatric disorders.
J Child Psychol Psychiatry
PUBLISHED: 07-08-2013
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The risk of childhood behavioural and psychiatric diseases could be substantially reduced if modifiable risk factors for these disorders were identified. The critical period for many of these exposures is likely to be in utero as this is the time when brain development is most rapid. However, due to confounding and other limitations of traditional epidemiological studies, identification of causal risk factors has proved challenging and on the whole research in this area has not been fruitful.
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Associations between active travel to work and overweight, hypertension, and diabetes in India: a cross-sectional study.
PLoS Med.
PUBLISHED: 06-01-2013
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Increasing active travel (walking, bicycling, and public transport) is promoted as a key strategy to increase physical activity and reduce the growing burden of noncommunicable diseases (NCDs) globally. Little is known about patterns of active travel or associated cardiovascular health benefits in low- and middle-income countries. This study examines mode and duration of travel to work in rural and urban India and associations between active travel and overweight, hypertension, and diabetes.
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Genome-wide meta-analysis identifies new susceptibility loci for migraine.
Verneri Anttila, Bendik S Winsvold, Padhraig Gormley, Tobias Kurth, Francesco Bettella, George McMahon, Mikko Kallela, Rainer Malik, Boukje de Vries, Gisela Terwindt, Sarah E Medland, Unda Todt, Wendy L McArdle, Lydia Quaye, Markku Koiranen, M Arfan Ikram, Terho Lehtimäki, Anine H Stam, Lannie Ligthart, Juho Wedenoja, Ian Dunham, Benjamin M Neale, Priit Palta, Eija Hämäläinen, Markus Schürks, Lynda M Rose, Julie E Buring, Paul M Ridker, Stacy Steinberg, Hreinn Stefansson, Finnbogi Jakobsson, Debbie A Lawlor, David M Evans, Susan M Ring, Markus Färkkilä, Ville Artto, Mari A Kaunisto, Tobias Freilinger, Jean Schoenen, Rune R Frants, Nadine Pelzer, Claudia M Weller, Ronald Zielman, Andrew C Heath, Pamela A F Madden, Grant W Montgomery, Nicholas G Martin, Guntram Borck, Hartmut Göbel, Axel Heinze, Katja Heinze-Kuhn, Frances M K Williams, Anna-Liisa Hartikainen, Anneli Pouta, Joyce van den Ende, André G Uitterlinden, Albert Hofman, Najaf Amin, Jouke-Jan Hottenga, Jacqueline M Vink, Kauko Heikkilä, Michael Alexander, Bertram Müller-Myhsok, Stefan Schreiber, Thomas Meitinger, Heinz Erich Wichmann, Arpo Aromaa, Johan G Eriksson, Bryan J Traynor, Daniah Trabzuni, Elizabeth Rossin, Kasper Lage, Suzanne B R Jacobs, J Raphael Gibbs, Ewan Birney, Jaakko Kaprio, Brenda W Penninx, Dorret I Boomsma, Cornelia van Duijn, Olli Raitakari, Marjo-Riitta Järvelin, John-Anker Zwart, Lynn Cherkas, David P Strachan, Christian Kubisch, Michel D Ferrari, Arn M J M van den Maagdenberg, Martin Dichgans, Maija Wessman, George Davey Smith, Kari Stefansson, Mark J Daly, Dale R Nyholt, Daniel I Chasman, Aarno Palotie, .
Nat. Genet.
PUBLISHED: 05-30-2013
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Migraine is the most common brain disorder, affecting approximately 14% of the adult population, but its molecular mechanisms are poorly understood. We report the results of a meta-analysis across 29 genome-wide association studies, including a total of 23,285 individuals with migraine (cases) and 95,425 population-matched controls. We identified 12 loci associated with migraine susceptibility (P<5×10(-8)). Five loci are new: near AJAP1 at 1p36, near TSPAN2 at 1p13, within FHL5 at 6q16, within C7orf10 at 7p14 and near MMP16 at 8q21. Three of these loci were identified in disease subgroup analyses. Brain tissue expression quantitative trait locus analysis suggests potential functional candidate genes at four loci: APOA1BP, TBC1D7, FUT9, STAT6 and ATP5B.
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Genome-wide association study identifies loci affecting blood copper, selenium and zinc.
Hum. Mol. Genet.
PUBLISHED: 05-29-2013
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Genetic variation affecting absorption, distribution or excretion of essential trace elements may lead to health effects related to sub-clinical deficiency. We have tested for allelic effects of single-nucleotide polymorphisms (SNPs) on blood copper, selenium and zinc in a genome-wide association study using two adult cohorts from Australia and the UK. Participants were recruited in Australia from twins and their families and in the UK from pregnant women. We measured erythrocyte Cu, Se and Zn (Australian samples) or whole blood Se (UK samples) using inductively coupled plasma mass spectrometry. Genotyping was performed with Illumina chips and > 2.5 m SNPs were imputed from HapMap data. Genome-wide significant associations were found for each element. For Cu, there were two loci on chromosome 1 (most significant SNPs rs1175550, P = 5.03 × 10(-10), and rs2769264, P = 2.63 × 10(-20)); for Se, a locus on chromosome 5 was significant in both cohorts (combined P = 9.40 × 10(-28) at rs921943); and for Zn three loci on chromosomes 8, 15 and X showed significant results (rs1532423, P = 6.40 × 10(-12); rs2120019, P = 1.55 × 10(-18); and rs4826508, P = 1.40 × 10(-12), respectively). The Se locus covers three genes involved in metabolism of sulphur-containing amino acids and potentially of the analogous Se compounds; the chromosome 8 locus for Zn contains multiple genes for the Zn-containing enzyme carbonic anhydrase. Where potentially relevant genes were identified, they relate to metabolism of the element (Se) or to the presence at high concentration of a metal-containing protein (Cu).
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Common variation contributes to the genetic architecture of social communication traits.
Mol Autism
PUBLISHED: 04-16-2013
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Social communication difficulties represent an autistic trait that is highly heritable and persistent during the course of development. However, little is known about the underlying genetic architecture of this phenotype.
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Jumping the gun: the problematic discourse on socioeconomic status and cardiovascular health in India.
Int J Epidemiol
PUBLISHED: 04-05-2013
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There has been an increased focus on non-communicable diseases (NCDs) in India, especially on cardiovascular diseases and associated risk factors. In this essay, we scrutinize the prevailing narrative that cardiovascular risk factors (CVRF) and cardiovascular disease (CVD) are no longer confined to the economically advantaged groups but are an increasing burden among the poor in India. We conducted a comprehensive review of studies reporting the association between socioeconomic status (SES) and CVRF, CVD, and CVD-related mortality in India. With the exception of smoking and low fruit and vegetable intake, the studies clearly suggest that CVRF/CVD is more prevalent among high SES groups in India than among the low SES groups. Although CVD-related mortality rates appear to be higher among the lower SES groups, the proportion of deaths from CVD-related causes was found to be greatest among higher SES groups. The studies on SES and CVRF/CVD also reveal a substantial discrepancy between the data presented and the authors interpretations and conclusions, along with an unsubstantiated claim that a reversal in the positive SES-CVRF/CVD association has occurred or is occurring in India. We conclude our essay by emphasizing the need to prioritize public health policies that are focused on the health concerns of the majority of the Indian population. Resource allocation in the context of efforts to make health care in India free and universal should reflect the proportional burden of disease on different population groups if it is not to entrench inequity.
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Issues in the reporting and conduct of instrumental variable studies: a systematic review.
Epidemiology
PUBLISHED: 03-28-2013
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Instrumental variables can be used to estimate the causal effects of exposures on outcomes in the presence of residual or uncontrolled confounding. To assess the validity of analyses using instrumental variables, specific information about whether underlying assumptions are met must be presented, in particular to demonstrate that the instrument is associated with the exposure but not with measured confounding factors. We systematically reviewed the epidemiological literature in Embase and Medline for articles containing the term "instrumental variable$" to investigate whether reporting of test statistics in studies using instrumental variables was sufficient to assess the validity of the results. We extracted the information each study reported about their instrumental variables, including specification tests used to check assumptions. The search found 756 studies of which 90 were relevant and were included. Only 25 (28%) studies reported appropriate tests of the strength of the associations between instruments and exposure. Forty-four (49%) studies reported associations between the instrumental variables and observed covariates. Studies using instrumental variables had wide confidence intervals and so effect estimates were imprecise. We propose a checklist of information and specification tests that studies using instrumental variables should report.
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COX-2 selective nonsteroidal anti-inflammatory drugs and risk of gastrointestinal tract complications and myocardial infarction: an instrumental variable analysis.
Epidemiology
PUBLISHED: 03-28-2013
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Instrumental variable analysis can estimate treatment effects in the presence of residual or unmeasured confounding. We compared ordinary least squares regression versus instrumental variable estimates of the effects of selective cyclooxygenase-2 inhibitors (COX-2s) relative to nonselective nonsteroidal anti-inflammatory drug (NSAID) prescriptions on incidence of upper gastrointestinal complications and myocardial infarction (MI).
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Identification of heart rate-associated loci and their effects on cardiac conduction and rhythm disorders.
Marcel den Hoed, Mark Eijgelsheim, Tonu Esko, Bianca J J M Brundel, David S Peal, David M Evans, Ilja M Nolte, Ayellet V Segrè, Hilma Holm, Robert E Handsaker, Harm-Jan Westra, Toby Johnson, Aaron Isaacs, Jian Yang, Alicia Lundby, Jing Hua Zhao, Young Jin Kim, Min Jin Go, Peter Almgren, Murielle Bochud, Gabrielle Boucher, Marilyn C Cornelis, Daniel Gudbjartsson, David Hadley, Pim van der Harst, Caroline Hayward, Martin den Heijer, Wilmar Igl, Anne U Jackson, Zoltan Kutalik, Jian'an Luan, John P Kemp, Kati Kristiansson, Claes Ladenvall, Mattias Lorentzon, May E Montasser, Omer T Njajou, Paul F O'Reilly, Sandosh Padmanabhan, Beate St Pourcain, Tuomo Rankinen, Perttu Salo, Toshiko Tanaka, Nicholas J Timpson, Veronique Vitart, Lindsay Waite, William Wheeler, Weihua Zhang, Harmen H M Draisma, Mary F Feitosa, Kathleen F Kerr, Penelope A Lind, Evelin Mihailov, N Charlotte Onland-Moret, Ci Song, Michael N Weedon, Weijia Xie, Loïc Yengo, Devin Absher, Christine M Albert, Alvaro Alonso, Dan E Arking, Paul I W de Bakker, Beverley Balkau, Cristina Barlassina, Paola Benaglio, Joshua C Bis, Nabila Bouatia-Naji, Søren Brage, Stephen J Chanock, Peter S Chines, Mina Chung, Dawood Darbar, Christian Dina, Marcus Dörr, Paul Elliott, Stephan B Felix, Krista Fischer, Christian Fuchsberger, Eco J C de Geus, Philippe Goyette, Vilmundur Gudnason, Tamara B Harris, Anna-Liisa Hartikainen, Aki S Havulinna, Susan R Heckbert, Andrew A Hicks, Albert Hofman, Suzanne Holewijn, Femke Hoogstra-Berends, Jouke-Jan Hottenga, Majken K Jensen, Asa Johansson, Juhani Junttila, Stefan Kääb, Bart Kanon, Shamika Ketkar, Kay-Tee Khaw, Joshua W Knowles, Angrad S Kooner, Jan A Kors, Meena Kumari, Lili Milani, Päivi Laiho, Edward G Lakatta, Claudia Langenberg, Maarten Leusink, Yongmei Liu, Robert N Luben, Kathryn L Lunetta, Stacey N Lynch, Marcello R P Markus, Pedro Marques-Vidal, Irene Mateo Leach, Wendy L McArdle, Steven A McCarroll, Sarah E Medland, Kathryn A Miller, Grant W Montgomery, Alanna C Morrison, Martina Müller-Nurasyid, Pau Navarro, Mari Nelis, Jeffrey R O'Connell, Christopher J O'Donnell, Ken K Ong, Anne B Newman, Annette Peters, Ozren Polašek, Anneli Pouta, Peter P Pramstaller, Bruce M Psaty, Dabeeru C Rao, Susan M Ring, Elizabeth J Rossin, Diana Rudan, Serena Sanna, Robert A Scott, Jaban S Sehmi, Stephen Sharp, Jordan T Shin, Andrew B Singleton, Albert V Smith, Nicole Soranzo, Tim D Spector, Chip Stewart, Heather M Stringham, Kirill V Tarasov, André G Uitterlinden, Liesbeth Vandenput, Shih-Jen Hwang, John B Whitfield, Cisca Wijmenga, Sarah H Wild, Gonneke Willemsen, James F Wilson, Jacqueline C M Witteman, Andrew Wong, Quenna Wong, Yalda Jamshidi, Paavo Zitting, Jolanda M A Boer, Dorret I Boomsma, Ingrid B Borecki, Cornelia M van Duijn, Ulf Ekelund, Nita G Forouhi, Philippe Froguel, Aroon Hingorani, Erik Ingelsson, Mika Kivimäki, Richard A Kronmal, Diana Kuh, Lars Lind, Nicholas G Martin, Ben A Oostra, Nancy L Pedersen, Thomas Quertermous, Jerome I Rotter, Yvonne T van der Schouw, W M Monique Verschuren, Mark Walker, Demetrius Albanes, David O Arnar, Themistocles L Assimes, Stefania Bandinelli, Michael Boehnke, Rudolf A de Boer, Claude Bouchard, W L Mark Caulfield, John C Chambers, Gary Curhan, Daniele Cusi, Johan Eriksson, Luigi Ferrucci, Wiek H van Gilst, Nicola Glorioso, Jacqueline de Graaf, Leif Groop, Ulf Gyllensten, Wen-Chi Hsueh, Frank B Hu, Heikki V Huikuri, David J Hunter, Carlos Iribarren, Bo Isomaa, Marjo-Riitta Järvelin, Antti Jula, Mika Kähönen, Lambertus A Kiemeney, Melanie M van der Klauw, Jaspal S Kooner, Peter Kraft, Licia Iacoviello, Terho Lehtimäki, Marja-Liisa L Lokki, Braxton D Mitchell, Gerjan Navis, Markku S Nieminen, Claes Ohlsson, Neil R Poulter, Lu Qi, Olli T Raitakari, Eric B Rimm, John D Rioux, Federica Rizzi, Igor Rudan, Veikko Salomaa, Peter S Sever, Denis C Shields, Alan R Shuldiner, Juha Sinisalo, Alice V Stanton, Ronald P Stolk, David P Strachan, Jean-Claude Tardif, Unnur Thorsteinsdottir, Jaako Tuomilehto, Dirk J van Veldhuisen, Jarmo Virtamo, Jorma Viikari, Peter Vollenweider, Gérard Waeber, Elisabeth Widén, Yoon Shin Cho, Jesper V Olsen, Peter M Visscher, Cristen Willer, Lude Franke, , Jeanette Erdmann, John R Thompson, Arne Pfeufer, Nona Sotoodehnia, Christopher Newton-Cheh, Patrick T Ellinor, Bruno H Ch Stricker, Andres Metspalu, Markus Perola, Jacques S Beckmann, George Davey Smith, Kari Stefansson, Nicholas J Wareham, Patricia B Munroe, Ody C M Sibon, David J Milan, Harold Snieder, Nilesh J Samani, Ruth J F Loos.
Nat. Genet.
PUBLISHED: 03-21-2013
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Elevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously established loci. Experimental downregulation of gene expression in Drosophila melanogaster and Danio rerio identified 20 genes at 11 loci that are relevant for heart rate regulation and highlight a role for genes involved in signal transmission, embryonic cardiac development and the pathophysiology of dilated cardiomyopathy, congenital heart failure and/or sudden cardiac death. In addition, genetic susceptibility to increased heart rate is associated with altered cardiac conduction and reduced risk of sick sinus syndrome, and both heart rate-increasing and heart rate-decreasing variants associate with risk of atrial fibrillation. Our findings provide fresh insights into the mechanisms regulating heart rate and identify new therapeutic targets.
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Genome-wide association and longitudinal analyses reveal genetic loci linking pubertal height growth, pubertal timing and childhood adiposity.
Hum. Mol. Genet.
PUBLISHED: 02-27-2013
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The pubertal height growth spurt is a distinctive feature of childhood growth reflecting both the central onset of puberty and local growth factors. Although little is known about the underlying genetics, growth variability during puberty correlates with adult risks for hormone-dependent cancer and adverse cardiometabolic health. The only gene so far associated with pubertal height growth, LIN28B, pleiotropically influences childhood growth, puberty and cancer progression, pointing to shared underlying mechanisms. To discover genetic loci influencing pubertal height and growth and to place them in context of overall growth and maturation, we performed genome-wide association meta-analyses in 18 737 European samples utilizing longitudinally collected height measurements. We found significant associations (P < 1.67 × 10(-8)) at 10 loci, including LIN28B. Five loci associated with pubertal timing, all impacting multiple aspects of growth. In particular, a novel variant correlated with expression of MAPK3, and associated both with increased prepubertal growth and earlier menarche. Another variant near ADCY3-POMC associated with increased body mass index, reduced pubertal growth and earlier puberty. Whereas epidemiological correlations suggest that early puberty marks a pathway from rapid prepubertal growth to reduced final height and adult obesity, our study shows that individual loci associating with pubertal growth have variable longitudinal growth patterns that may differ from epidemiological observations. Overall, this study uncovers part of the complex genetic architecture linking pubertal height growth, the timing of puberty and childhood obesity and provides new information to pinpoint processes linking these traits.
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A genome-wide association study for corneal curvature identifies the platelet-derived growth factor receptor ? gene as a quantitative trait locus for eye size in white Europeans.
Mol. Vis.
PUBLISHED: 02-01-2013
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Corneal curvature is a key determinant of the refractive power of the eye. Variants in two genes, FKBP12-rapamycin complex-associated protein 1 (FRAP1) on chromosome 1p36.2 and platelet-derived growth factor receptor alpha (PDGFRA) on chromosome 4q12, have shown genome-wide significant association with normal variation in corneal curvature in a study of subjects of Asian origin. Variants at the PDGFRA locus have also shown genome-wide significant association with corneal astigmatism. Whether these variants influence other ocular parameters such as axial length has yet to be reported. We performed a genome-wide association study for corneal curvature in white European subjects from a population-based birth cohort, with the aim of replicating and extending the above findings.
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Using mendelian randomisation to infer causality in depression and anxiety research.
Depress Anxiety
PUBLISHED: 01-24-2013
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Depression and anxiety co-occur with substance use and abuse at a high rate. Ascertaining whether substance use plays a causal role in depression and anxiety is difficult or impossible with conventional observational epidemiology. Mendelian randomisation uses genetic variants as a proxy for environmental exposures, such as substance use, which can address problems of reverse causation and residual confounding, providing stronger evidence about causality. Genetic variants can be used instead of directly measuring exposure levels, in order to gain an unbiased estimate of the effect of various exposures on depression and anxiety. The suitability of the genetic variant as a proxy can be ascertained by confirming that there is no relationship between variant and outcome in those who do not use the substance. At present, there are suitable instruments for tobacco use, so we use that as a case study. Proof-of-principle Mendelian randomisation studies using these variants have found evidence for a causal effect of smoking on body mass index. Two studies have investigated tobacco and depression using this method, but neither found strong evidence that smoking causes depression or anxiety; evidence is more consistent with a self-medication hypothesis. Mendelian randomisation represents a technique that can aid understanding of exposures that may or may not be causally related to depression and anxiety. As more suitable instruments emerge (including the use of allelic risk scores rather than individual single nucleotide polymorphisms), the effect of other substances can be investigated. Linkage disequilibrium, pleiotropy, and population stratification, which can distort Mendelian randomisation studies, are also discussed.
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Analysis of body composition in individuals with high bone mass reveals a marked increase in fat mass in women but not men.
J. Clin. Endocrinol. Metab.
PUBLISHED: 01-21-2013
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High bone mass (HBM), detected in 0.2% of dual-energy x-ray absorptiometry (DXA) scans, is characterized by raised body mass index, the basis for which is unclear.
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Association study of 25 type 2 diabetes related Loci with measures of obesity in Indian sib pairs.
PLoS ONE
PUBLISHED: 01-17-2013
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Obesity is an established risk factor for type 2 diabetes (T2D) and they are metabolically related through the mechanism of insulin resistance. In order to explore how common genetic variants associated with T2D correlate with body mass index (BMI), we examined the influence of 25 T2D associated loci on obesity risk. We used 5056 individuals (2528 sib-pairs) recruited in Indian Migration Study and conducted within sib-pair analysis for six obesity phenotypes. We found associations of variants in CXCR4 (rs932206) and HHEX (rs5015480) with higher body mass index (BMI) (?=0.13, p=0.001) and (?=0.09, p=0.002), respectively and weight (?=0.13, p=0.001) and (?=0.09, p=0.001), respectively. CXCR4 variant was also strongly associated with body fat (?=0.10, p=0.0004). In addition, we demonstrated associations of CXCR4 and HHEX with overweight/obesity (OR=1.6, p=0.003) and (OR=1.4, p=0.002), respectively, in 1333 sib-pairs (2666 individuals). We observed marginal evidence of associations between variants at six loci (TCF7L2, NGN3, FOXA2, LOC646279, FLJ39370 and THADA) and waist hip ratio (WHR), BMI and/or overweight which needs to be validated in larger set of samples. All the above findings were independent of daily energy consumption and physical activity level. The risk score estimates based on eight significant loci (including nominal associations) showed associations with WHR and body fat which were independent of BMI. In summary, we establish the role of T2D associated loci in influencing the measures of obesity in Indian population, suggesting common underlying pathophysiology across populations.
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Lack of emergence of associations between selected maternal exposures and offspring blood pressure at age 15 years.
J Epidemiol Community Health
PUBLISHED: 01-15-2013
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A recent review found little evidence for substantial effects of modifiable maternal exposures on offspring blood pressure (BP), but this may have been because almost all the studies reported on BP in early and mid-childhood.
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Effects of Nutritional Supplementation during Pregnancy on Early Adult Disease Risk: Follow Up of Offspring of Participants in a Randomised Controlled Trial Investigating Effects of Supplementation on Infant Birth Weight.
PLoS ONE
PUBLISHED: 01-01-2013
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Observational evidence suggests that improving fetal growth may improve adult health. Experimental evidence from nutritional supplementation trials undertaken amongst pregnant women in the less developed world does not show strong or consistent effects on adult disease risk and no trials from the more developed world have previously been reported.
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Area-level deprivation and overall and cause-specific mortality: 12 years observation on british women and systematic review of prospective studies.
PLoS ONE
PUBLISHED: 01-01-2013
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Prospective studies have suggested a negative impact of area deprivation on overall mortality, but its effect on cause-specific mortality and the mechanisms that account for this association remain unclear. We investigate the association of area deprivation, using Index of Multiple deprivation (IMD), with overall and cause-specific mortality, contextualising findings within a systematic review.
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Association between milk and milk product consumption and anthropometric measures in adult men and women in India: a cross-sectional study.
PLoS ONE
PUBLISHED: 01-01-2013
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The nutritional aetiology of obesity remains unclear, especially with regard to the role of dairy products in developing countries.
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Postnatal growth and DNA methylation are associated with differential gene expression of the TACSTD2 gene and childhood fat mass.
Diabetes
PUBLISHED: 12-21-2011
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Rapid postnatal growth is associated with increased risk of childhood adiposity. The aim of this study was to establish whether this pathway is mediated by altered DNA methylation and gene expression. Two distinct cohorts, one preterm (n=121) and one term born (n=6,990), were studied. Exploratory analyses were performed using microarrays to identify differentially expressed genes in whole blood from children defined as "slow" (n=10) compared with "rapid" (n=10) postnatal (term to 12 weeks corrected age) growers. Methylation within the identified TACSTD2 gene was measured in both cohorts, and rs61779296 genotype was determined by Pyrosequencing or imputation and analyzed in relation to body composition at 9-15 years of age. In cohort 1, TACSTD2 expression was inversely correlated with methylation (P=0.016), and both measures were associated with fat mass (expression, P=0.049; methylation, P=0.037). Although associated with gene expression (cohort 1, P=0.008) and methylation (cohort 1, P=2.98×10(-11); cohort 2, P=3.43×10(-15)), rs61779296 was not associated with postnatal growth or fat mass in either cohort following multiple regression analysis. Hence, the lack of association between fat mass and a methylation proxy SNP suggests that reverse causation or confounding may explain the initial association between fat mass and gene regulation. Noncausal methylation patterns may still be useful predictors of later adiposity.
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Circulating insulin-like growth factors and IGF-binding proteins in PSA-detected prostate cancer: the large case-control study ProtecT.
Cancer Res.
PUBLISHED: 11-21-2011
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Circulating insulin-like growth factor-I (IGF-I) has been studied extensively in prostate cancer, but there is still little information about IGFs and IGF-binding proteins (IGFBP) in cancers detected by the prostate-specific antigen (PSA) test. Here, we report the findings of a U.K.-based case-control study to investigate circulating IGFs and IGFBPs in PSA-detected prostate cancer with regard to their potential associations with different cancer stages or grades. PSA testing was offered to 110,000 men aged 50 to 69 years from 2002 to 2009. Participants with an elevated level of PSA (?3.0 ng/mL) underwent prostate biopsy and measurements of blood serum IGF-I, IGF-II, IGFBP-2, and IGFBP-3 obtained at recruitment. We found that serum levels of IGF-II (OR per SD increase: 1.16; 95% CI: 1.08-1.24; P(trend) < 0.001), IGFBP-2 (1.18; 1.06-1.31; P(trend) < 0.01) and IGFBP-3 (1.27; 1.19-1.36; P(trend) < 0.001), but not IGF-I (0.99; 0.93-1.04; P(trend) = 0.62), were associated with PSA-detected prostate cancer. After controlling for IGFBP-3, IGF-II was no longer associated (0.99; 0.91-1.08; P(trend) = 0.62) and IGF-I was inversely associated (0.85; 0.79-0.91; P(trend) < 0.001) with prostate cancer. In addition, no strong associations existed with cancer stage or grade. Overall, these findings suggest potentially important roles for circulating IGF-II, IGFBP-2, and IGFBP-3 in PSA-detected prostate cancer, in support of recent in vitro evidence. Although our findings for IGF-I agree with previous results from PSA screening trials, they contrast with positive associations in routinely detected disease, suggesting that reducing levels of circulating IGF-I might not prevent the initiation of prostate cancer but might, nonetheless, prevent its progression.
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Is infant weight associated with childhood blood pressure? Analysis of the Promotion of Breastfeeding Intervention Trial (PROBIT) cohort.
Int J Epidemiol
PUBLISHED: 09-03-2011
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Weight gain during infancy may programme later health outcomes, but examination of this hypothesis requires appropriate lifecourse methods and detailed weight gain measures during childhood. We examined associations between weight gain in infancy and early childhood and blood pressure at the age of 6.5 years in healthy children born at term.
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Pre-conception inter-pregnancy interval and risk of schizophrenia.
Br J Psychiatry
PUBLISHED: 08-04-2011
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It is hypothesised that the risk of schizophrenia may be elevated in children conceived following a short inter-pregnancy interval, when maternal folate stores are still being replenished. We examined the relationship between inter-pregnancy interval and schizophrenia risk in a longitudinal, population-based cohort. Risk of schizophrenia was increased by approximately 150% in those born following a pregnancy interval of ?6 months, but was not increased if the interval after birth of the participant, before conception of the subsequent sibling, was ?6 months. These findings support the hypothesis that folate (or other micronutrient) deficiency during fetal development may be an important risk factor for schizophrenia.
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Epidemiology, epigenetics and the Gloomy Prospect: embracing randomness in population health research and practice.
Int J Epidemiol
PUBLISHED: 08-03-2011
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Epidemiologists aim to identify modifiable causes of disease, this often being a prerequisite for the application of epidemiological findings in public health programmes, health service planning and clinical medicine. Despite successes in identifying causes, it is often claimed that there are missing additional causes for even reasonably well-understood conditions such as lung cancer and coronary heart disease. Several lines of evidence suggest that largely chance events, from the biographical down to the sub-cellular, contribute an important stochastic element to disease risk that is not epidemiologically tractable at the individual level. Epigenetic influences provide a fashionable contemporary explanation for such seemingly random processes. Chance events-such as a particular lifelong smoker living unharmed to 100 years-are averaged out at the group level. As a consequence population-level differences (for example, secular trends or differences between administrative areas) can be entirely explicable by causal factors that appear to account for only a small proportion of individual-level risk. In public health terms, a modifiable cause of the large majority of cases of a disease may have been identified, with a wild goose chase continuing in an attempt to discipline the random nature of the world with respect to which particular individuals will succumb. The quest for personalized medicine is a contemporary manifestation of this dream. An evolutionary explanation of why randomness exists in the development of organisms has long been articulated, in terms of offering a survival advantage in changing environments. Further, the basic notion that what is near-random at one level may be almost entirely predictable at a higher level is an emergent property of many systems, from particle physics to the social sciences. These considerations suggest that epidemiological approaches will remain fruitful as we enter the decade of the epigenome.
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Prediction of childhood obesity by infancy weight gain: an individual-level meta-analysis.
Paediatr Perinat Epidemiol
PUBLISHED: 08-01-2011
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To assess the predictive ability of infant weight gain on subsequent obesity we performed a meta-analysis of individual-level data on 47,661 participants from 10 cohort studies from the UK, France, Finland, Sweden, the US and Seychelles. For each individual, weight SD scores at birth and age 1 year were calculated using the same external reference (British 1990). Childhood obesity was defined by International Obesity Task Force criteria. Each +1 unit increase in weight SD scores between 0 and 1 year conferred a twofold higher risk of childhood obesity (odds ratio = 1.97 [95% confidence interval (CI) 1.83, 2.12]), and a 23% higher risk of adult obesity (odds ratio = 1.23 [1.16, 1.30]), adjusted for sex, age and birthweight. There was little heterogeneity between studies. A risk score for childhood obesity comprising weight gain 0-1 year, mothers body mass index, birthweight and sex was generated in a random 50% selection of individuals from general population cohorts with available information (n = 8236); this score showed moderate predictive ability in the remaining 50% sample (area under receiving operating curve = 77% [95% CI 74, 80%]). A separate risk score for childhood overweight showed similar predictive ability (area under receiving operating curve = 76% [73, 79%]). In conclusion, infant weight gain showed a consistent positive association with subsequent obesity. A risk score combining birthweight and infant weight gain (or simply infant weight), together with mothers body mass index and sex may allow early stratification of infants at risk of childhood obesity.
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Effect modification by population dietary folate on the association between MTHFR genotype, homocysteine, and stroke risk: a meta-analysis of genetic studies and randomised trials.
Lancet
PUBLISHED: 07-29-2011
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The MTHFR 677C?T polymorphism has been associated with raised homocysteine concentration and increased risk of stroke. A previous overview showed that the effects were greatest in regions with low dietary folate consumption, but differentiation between the effect of folate and small-study bias was difficult. A meta-analysis of randomised trials of homocysteine-lowering interventions showed no reduction in coronary heart disease events or stroke, but the trials were generally set in populations with high folate consumption. We aimed to reduce the effect of small-study bias and investigate whether folate status modifies the association between MTHFR 677C?T and stroke in a genetic analysis and meta-analysis of randomised controlled trials.
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Genetic variants in novel pathways influence blood pressure and cardiovascular disease risk.
, Georg B Ehret, Patricia B Munroe, Kenneth M Rice, Murielle Bochud, Andrew D Johnson, Daniel I Chasman, Albert V Smith, Martin D Tobin, Germaine C Verwoert, Shih-Jen Hwang, Vasyl Pihur, Peter Vollenweider, Paul F O'Reilly, Najaf Amin, Jennifer L Bragg-Gresham, Alexander Teumer, Nicole L Glazer, Lenore Launer, Jing Hua Zhao, Yurii Aulchenko, Simon Heath, Siim Sõber, Afshin Parsa, Jian'an Luan, Pankaj Arora, Abbas Dehghan, Feng Zhang, Gavin Lucas, Andrew A Hicks, Anne U Jackson, John F Peden, Toshiko Tanaka, Sarah H Wild, Igor Rudan, Wilmar Igl, Yuri Milaneschi, Alex N Parker, Cristiano Fava, John C Chambers, Ervin R Fox, Meena Kumari, Min Jin Go, Pim van der Harst, Wen Hong Linda Kao, Marketa Sjögren, D G Vinay, Myriam Alexander, Yasuharu Tabara, Sue Shaw-Hawkins, Peter H Whincup, Yongmei Liu, Gang Shi, Johanna Kuusisto, Bamidele Tayo, Mark Seielstad, Xueling Sim, Khanh-Dung Hoang Nguyen, Terho Lehtimäki, Giuseppe Matullo, Ying Wu, Tom R Gaunt, N Charlotte Onland-Moret, Matthew N Cooper, Carl G P Platou, Elin Org, Rebecca Hardy, Santosh Dahgam, Jutta Palmen, Veronique Vitart, Peter S Braund, Tatiana Kuznetsova, Cuno S P M Uiterwaal, Adebowale Adeyemo, Walter Palmas, Harry Campbell, Barbara Ludwig, Maciej Tomaszewski, Ioanna Tzoulaki, Nicholette D Palmer, Thor Aspelund, Melissa Garcia, Yen-Pei C Chang, Jeffrey R O'Connell, Nanette I Steinle, Diederick E Grobbee, Dan E Arking, Sharon L Kardia, Alanna C Morrison, Dena Hernandez, Samer Najjar, Wendy L McArdle, David Hadley, Morris J Brown, John M Connell, Aroon D Hingorani, Ian N M Day, Debbie A Lawlor, John P Beilby, Robert W Lawrence, Robert Clarke, Jemma C Hopewell, Halit Ongen, Albert W Dreisbach, Yali Li, J Hunter Young, Joshua C Bis, Mika Kähönen, Jorma Viikari, Linda S Adair, Nanette R Lee, Ming-Huei Chen, Matthias Olden, Cristian Pattaro, Judith A Hoffman Bolton, Anna Köttgen, Sven Bergmann, Vincent Mooser, Nish Chaturvedi, Timothy M Frayling, Muhammad Islam, Tazeen H Jafar, Jeanette Erdmann, Smita R Kulkarni, Stefan R Bornstein, Jürgen Gräßler, Leif Groop, Benjamin F Voight, Johannes Kettunen, Philip Howard, Andrew Taylor, Simonetta Guarrera, Fulvio Ricceri, Valur Emilsson, Andrew Plump, Inês Barroso, Kay-Tee Khaw, Alan B Weder, Steven C Hunt, Yan V Sun, Richard N Bergman, Francis S Collins, Lori L Bonnycastle, Laura J Scott, Heather M Stringham, Leena Peltonen, Markus Perola, Erkki Vartiainen, Stefan-Martin Brand, Jan A Staessen, Thomas J Wang, Paul R Burton, María Soler Artigas, Yanbin Dong, Harold Snieder, Xiaoling Wang, Haidong Zhu, Kurt K Lohman, Megan E Rudock, Susan R Heckbert, Nicholas L Smith, Kerri L Wiggins, Ayo Doumatey, Daniel Shriner, Gudrun Veldre, Margus Viigimaa, Sanjay Kinra, Dorairaj Prabhakaran, Vikal Tripathy, Carl D Langefeld, Annika Rosengren, Dag S Thelle, Anna Maria Corsi, Andrew Singleton, Terrence Forrester, Gina Hilton, Colin A McKenzie, Tunde Salako, Naoharu Iwai, Yoshikuni Kita, Toshio Ogihara, Takayoshi Ohkubo, Tomonori Okamura, Hirotsugu Ueshima, Satoshi Umemura, Susana Eyheramendy, Thomas Meitinger, H-Erich Wichmann, Yoon Shin Cho, Hyung-Lae Kim, Jong-Young Lee, James Scott, Joban S Sehmi, Weihua Zhang, Bo Hedblad, Peter Nilsson, George Davey Smith, Andrew Wong, Narisu Narisu, Alena Stančáková, Leslie J Raffel, Jie Yao, Sekar Kathiresan, Christopher J O'Donnell, Stephen M Schwartz, M Arfan Ikram, W T Longstreth, Thomas H Mosley, Sudha Seshadri, Nick R G Shrine, Louise V Wain, Mario A Morken, Amy J Swift, Jaana Laitinen, Inga Prokopenko, Paavo Zitting, Jackie A Cooper, Steve E Humphries, John Danesh, Asif Rasheed, Anuj Goel, Anders Hamsten, Hugh Watkins, Stephan J L Bakker, Wiek H van Gilst, Charles S Janipalli, K Radha Mani, Chittaranjan S Yajnik, Albert Hofman, Francesco U S Mattace-Raso, Ben A Oostra, Ayse Demirkan, Aaron Isaacs, Fernando Rivadeneira, Edward G Lakatta, Marco Orrù, Angelo Scuteri, Mika Ala-Korpela, Antti J Kangas, Leo-Pekka Lyytikäinen, Pasi Soininen, Taru Tukiainen, Peter Würtz, Rick Twee-Hee Ong, Marcus Dörr, Heyo K Kroemer, Uwe Völker, Henry Völzke, Pilar Galán, Serge Hercberg, Mark Lathrop, Diana Zelenika, Panos Deloukas, Massimo Mangino, Tim D Spector, Guangju Zhai, James F Meschia, Michael A Nalls, Pankaj Sharma, Janos Terzic, M V Kranthi Kumar, Matthew Denniff, Ewa Zukowska-Szczechowska, Lynne E Wagenknecht, F Gerald R Fowkes, Fadi J Charchar, Peter E H Schwarz, Caroline Hayward, Xiuqing Guo, Charles Rotimi, Michiel L Bots, Eva Brand, Nilesh J Samani, Ozren Polašek, Philippa J Talmud, Fredrik Nyberg, Diana Kuh, Maris Laan, Kristian Hveem, Lyle J Palmer, Yvonne T van der Schouw, Juan P Casas, Karen L Mohlke, Paolo Vineis, Olli Raitakari, Santhi K Ganesh, Tien Y Wong, E Shyong Tai, Richard S Cooper, Markku Laakso, Dabeeru C Rao, Tamara B Harris, Richard W Morris, Anna F Dominiczak, Mika Kivimäki, Michael G Marmot, Tetsuro Miki, Danish Saleheen, Giriraj R Chandak, Josef Coresh, Gerjan Navis, Veikko Salomaa, Bok-Ghee Han, Xiaofeng Zhu, Jaspal S Kooner, Olle Melander, Paul M Ridker, Stefania Bandinelli, Ulf B Gyllensten, Alan F Wright, James F Wilson, Luigi Ferrucci, Martin Farrall, Jaakko Tuomilehto, Peter P Pramstaller, Roberto Elosua, Nicole Soranzo, Eric J G Sijbrands, David Altshuler, Ruth J F Loos, Alan R Shuldiner, Christian Gieger, Pierre Meneton, André G Uitterlinden, Nicholas J Wareham, Vilmundur Gudnason, Jerome I Rotter, Rainer Rettig, Manuela Uda, David P Strachan, Jacqueline C M Witteman, Anna-Liisa Hartikainen, Jacques S Beckmann, Eric Boerwinkle, Ramachandran S Vasan, Michael Boehnke, Martin G Larson, Marjo-Riitta Järvelin, Bruce M Psaty, Gonçalo R Abecasis, Aravinda Chakravarti, Paul Elliott, Cornelia M van Duijn, Christopher Newton-Cheh, Daniel Levy, Mark J Caulfield, Toby Johnson.
Nature
PUBLISHED: 07-28-2011
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Blood pressure is a heritable trait influenced by several biological pathways and responsive to environmental stimuli. Over one billion people worldwide have hypertension (?140?mm?Hg systolic blood pressure or? ?90?mm?Hg diastolic blood pressure). Even small increments in blood pressure are associated with an increased risk of cardiovascular events. This genome-wide association study of systolic and diastolic blood pressure, which used a multi-stage design in 200,000 individuals of European descent, identified sixteen novel loci: six of these loci contain genes previously known or suspected to regulate blood pressure (GUCY1A3-GUCY1B3, NPR3-C5orf23, ADM, FURIN-FES, GOSR2, GNAS-EDN3); the other ten provide new clues to blood pressure physiology. A genetic risk score based on 29 genome-wide significant variants was associated with hypertension, left ventricular wall thickness, stroke and coronary artery disease, but not kidney disease or kidney function. We also observed associations with blood pressure in East Asian, South Asian and African ancestry individuals. Our findings provide new insights into the genetics and biology of blood pressure, and suggest potential novel therapeutic pathways for cardiovascular disease prevention.
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The causal roles of vitamin B(12) and transcobalamin in prostate cancer: can Mendelian randomization analysis provide definitive answers?
Int J Mol Epidemiol Genet
PUBLISHED: 07-23-2011
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Circulating vitamin B(12) (cobalamin/B(12)) and total transcobalamin (tTC) have been associated with increased and reduced risk, respectively, of prostate cancer. Mendelian randomization has the potential to determine whether these are causal associations. We estimated associations of single nucleotide polymorphisms in B(12)-related genes (MTR, MTRR, FUT2, TCN2, TCN1, CUBN, and MUT) with plasma concentrations of B(12), tTC, holo-transcobalamin, holo-haptocorrin, folate, and homocysteine and with prostate cancer risk in a case-control study (913 cases, 895 controls) nested within the UK-wide population-based ProtecT study of prostate cancer in men age 45-69 years. Instrumental variable (IV) analysis was used to estimate odds ratios for effects of B(12) and tTC on prostate cancer. We observed that B(12) was lower in men with FUT2 204G>A (rs492602), CUBN 758C>T (rs1801222) and MUT 1595G>A (rs1141321) alleles (P(trend)<0.001); tTC was lower in men with the TCN2 776C>G (rs1801198) allele (P(trend)<0.001). FUT2 204G>A and CUBN 758C>T were selected as instruments for B(12); TCN2 776C>G for tTC. Conventional and IV estimates for the association of log(e)(B(12)) with prostate cancer were: OR=1.17 (95% CI 0.90-1.51), P=0.2 and OR=0.60 (0.16-2.15), P=0.4, respectively. Conventional and IV estimates for the association of loge(tTC) with prostate cancer were: OR=0.81 (0.54-1.20), P=0.3 and OR=0.41 (0.13-1.32), P=0.1, respectively. Confidence intervals around the IV estimates in our study were too wide to allow robust inference. Sample size estimates based on our data indicated that Mendelian randomization in this context requires much larger studies or multiple genetic variants that explain all of the variance in the intermediate phenotype.
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Adult height variants affect birth length and growth rate in children.
Hum. Mol. Genet.
PUBLISHED: 07-14-2011
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Previous studies identified 180 single nucleotide polymorphisms (SNPs) associated with adult height, explaining ?10% of the variance. The age at which these begin to affect growth is unclear. We modelled the effect of these SNPs on birth length and childhood growth. A total of 7768 participants in the Avon Longitudinal Study of Parents and Children had data available. Individual growth trajectories from 0 to 10 years were estimated using mixed-effects linear spline models and differences in trajectories by individual SNPs and allelic score were determined. The allelic score was associated with birth length (0.026 cm increase per tall allele, SE = 0.003, P = 1 × 10(-15), equivalent to 0.017 SD). There was little evidence of association between the allelic score and early infancy growth (0-3 months), but there was evidence of association between the allelic score and later growth. This association became stronger with each consecutive growth period, per tall allele per month effects were 0.015 SD (3 months-1 year, SE = 0.004), 0.023 SD (1-3 years, SE = 0.003) and 0.028 SD (3-10 years, SE = 0.003). By age 10, the mean height difference between individuals with ?170 versus ?191 tall alleles (the top and bottom 10%) was 4.7 cm (0.8 SD), explaining ?5% of the variance. There was evidence of associations with specific growth periods for some SNPs (rs3791675, EFEMP1 and rs6569648, L3MBTL3) and supportive evidence for previously reported age-dependent effects of HHIP and SOCS2 SNPs. SNPs associated with adult height influence birth length and have an increasing effect on growth from late infancy through to late childhood. By age 10, they explain half the height variance (?5%) of that explained in adults (?10%).
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Meta-analysis of genome-wide association studies identifies three new risk loci for atopic dermatitis.
Lavinia Paternoster, Marie Standl, Chih-Mei Chen, Adaikalavan Ramasamy, Klaus Bønnelykke, Liesbeth Duijts, Manuel A Ferreira, Alexessander Couto Alves, Jacob P Thyssen, Eva Albrecht, Hansjörg Baurecht, Bjarke Feenstra, Patrick M A Sleiman, Pirro Hysi, Nicole M Warrington, Ivan Curjuric, Ronny Myhre, John A Curtin, Maria M Groen-Blokhuis, Marjan Kerkhof, Annika Sääf, Andre Franke, David Ellinghaus, Regina Fölster-Holst, Emmanouil Dermitzakis, Stephen B Montgomery, Holger Prokisch, Katharina Heim, Anna-Liisa Hartikainen, Anneli Pouta, Juha Pekkanen, Alexandra I F Blakemore, Jessica L Buxton, Marika Kaakinen, David L Duffy, Pamela A Madden, Andrew C Heath, Grant W Montgomery, Philip J Thompson, Melanie C Matheson, Peter Le Souef, , Beate St Pourcain, George Davey Smith, John Henderson, John P Kemp, Nicholas J Timpson, Panos Deloukas, Susan M Ring, H-Erich Wichmann, Martina Müller-Nurasyid, Natalija Novak, Norman Klopp, Elke Rodríguez, Wendy McArdle, Allan Linneberg, Torkil Menné, Ellen A Nohr, Albert Hofman, André G Uitterlinden, Cornelia M van Duijn, Fernando Rivadeneira, Johan C de Jongste, Ralf J P van der Valk, Matthias Wjst, Rain Jõgi, Frank Geller, Heather A Boyd, Jeffrey C Murray, Cecilia Kim, Frank Mentch, Michael March, Massimo Mangino, Tim D Spector, Veronique Bataille, Craig E Pennell, Patrick G Holt, Peter Sly, Carla M T Tiesler, Elisabeth Thiering, Thomas Illig, Medea Imboden, Wenche Nystad, Angela Simpson, Jouke-Jan Hottenga, Dirkje Postma, Gerard H Koppelman, Henriëtte A Smit, Cilla Söderhäll, Bo Chawes, Eskil Kreiner-Møller, Hans Bisgaard, Erik Melén, Dorret I Boomsma, Adnan Custovic, Bo Jacobsson, Nicole M Probst-Hensch, Lyle J Palmer, Daniel Glass, Hakon Hakonarson, Mads Melbye, Deborah L Jarvis, Vincent W V Jaddoe, Christian Gieger, David P Strachan, Nicholas G Martin, Marjo-Riitta Järvelin, Joachim Heinrich, David M Evans, Stephan Weidinger.
Nat. Genet.
PUBLISHED: 07-08-2011
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Atopic dermatitis (AD) is a commonly occurring chronic skin disease with high heritability. Apart from filaggrin (FLG), the genes influencing atopic dermatitis are largely unknown. We conducted a genome-wide association meta-analysis of 5,606 affected individuals and 20,565 controls from 16 population-based cohorts and then examined the ten most strongly associated new susceptibility loci in an additional 5,419 affected individuals and 19,833 controls from 14 studies. Three SNPs reached genome-wide significance in the discovery and replication cohorts combined, including rs479844 upstream of OVOL1 (odds ratio (OR) = 0.88, P = 1.1 × 10(-13)) and rs2164983 near ACTL9 (OR = 1.16, P = 7.1 × 10(-9)), both of which are near genes that have been implicated in epidermal proliferation and differentiation, as well as rs2897442 in KIF3A within the cytokine cluster at 5q31.1 (OR = 1.11, P = 3.8 × 10(-8)). We also replicated association with the FLG locus and with two recently identified association signals at 11q13.5 (rs7927894; P = 0.008) and 20q13.33 (rs6010620; P = 0.002). Our results underline the importance of both epidermal barrier function and immune dysregulation in atopic dermatitis pathogenesis.
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Smoking is associated with, but does not cause, depressed mood in pregnancy--a mendelian randomization study.
PLoS ONE
PUBLISHED: 06-08-2011
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Smokers have a higher prevalence of major depressive episodes and depressive symptoms than the general population, but whether this association is causal, or is due to confounding or reverse causation is uncertain because of the problems inherent in some epidemiological studies. Mendelian randomization, in which a genetic variant is used as a surrogate for measuring exposure, is an approach which may be used to better understand this association. We investigated the rs1051730 single nucleotide polymorphism in the nicotine acetylcholine receptor gene cluster (CHRNA5-CHRNA3-CHRNB4), associated with smoking phenotypes, to determine whether women who continued to smoke were also more likely to report a low mood during pregnancy. We found among women who smoked pre-pregnancy, those with the 1051730 T allele smoked more and were less likely to quit smoking during pregnancy, but were also less likely to report high levels of depressed mood at 18 weeks of pregnancy (per allele OR?=?0.84, 95%CI 0.72 to 0.99, p?=?0.034). The association between genotype and depressed mood was limited to women who were smokers prior to pregnancy, with weak evidence of an interaction between smoking status and genotype (p?=?0.07). Our results do not support a causal role of smoking on depressed mood, but are consistent with a self-medication hypothesis, whereby smoking is used to alleviate symptoms of depression. A replication study using multiple genetic variants which influence smoking via different pathways is required to confirm these findings and provide evidence that the genetic variant is reflecting the effect of quitting smoking on depressed mood, and is not directly affecting mood.
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Association between urban life-years and cardiometabolic risk: the Indian migration study.
Am. J. Epidemiol.
PUBLISHED: 05-27-2011
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Urban living is associated with an increase in cardiometabolic risks, but the speed at which these risks are accrued over time is unknown. Using a cross-sectional sibling-pair design, the authors surveyed migrant factory workers and their spouses from 4 cities in India together with their rural-dwelling siblings and examined the associations between urban life-years and cardiometabolic risk factors. Data on 4,221 participants (39% women; mean age = 41 years) were available (2005-2007). In regression models, a 2-slope pattern for body fat (with a marked shift at 10 years) was found, whereas a common slope could be accepted for other risk factors. In men, the regression coefficients (per decade of urban life) were 2.5% in the first decade and 0.1% thereafter for body fat; 1.4 mm Hg for systolic blood pressure; and 7% for fasting insulin. Age, gender, marital status, household structure, and occupation did not influence the patterns appreciably; however, stronger gradients for adiposity were noted in migrants from lower socioeconomic positions. The findings suggest that body fat increases rapidly when one first moves to an urban environment, whereas other cardiometabolic risk factors evolve gradually. Public health interventions focused on the control of obesity in newer migrants to urban areas, particularly those from lower socioeconomic positions, may be beneficial.
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Is relative leg length a biomarker of childhood nutrition? Long-term follow-up of the Hyderabad Nutrition Trial.
Int J Epidemiol
PUBLISHED: 05-10-2011
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Relative leg length is frequently used as a biomarker of childhood nutrition in epidemiological studies, but evidence is lacking. We examined the association between supplemental nutrition in pregnancy and childhood and relative proportions of components of height in adolescence.
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Instrumental variable estimation of causal risk ratios and causal odds ratios in Mendelian randomization analyses.
Am. J. Epidemiol.
PUBLISHED: 05-09-2011
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In this paper, the authors describe different instrumental variable (IV) estimators of causal risk ratios and odds ratios with particular attention to methods that can handle continuously measured exposures. The authors present this discussion in the context of a Mendelian randomization analysis of the effect of body mass index (BMI; weight (kg)/height (m)(2)) on the risk of asthma at age 7 years (Avon Longitudinal Study of Parents and Children, 1991-1992). The authors show that the multiplicative structural mean model (MSMM) and the multiplicative generalized method of moments (MGMM) estimator produce identical estimates of the causal risk ratio. In the example, MSMM and MGMM estimates suggested an inverse relation between BMI and asthma but other IV estimates suggested a positive relation, although all estimates had wide confidence intervals. An interaction between the associations of BMI and fat mass and obesity-associated (FTO) genotype with asthma explained the different directions of the different estimates, and a simulation study supported the observation that MSMM/MGMM estimators are negatively correlated with the other estimators when such an interaction is present. The authors conclude that point estimates from various IV methods can differ in practical applications. Based on the theoretical properties of the estimators, structural mean models make weaker assumptions than other IV estimators and can therefore be expected to be consistent in a wider range of situations.
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The CRP genotype, serum levels and lung function in men: the Caerphilly Prospective Study.
Clin. Sci.
PUBLISHED: 05-07-2011
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Systemic CRP (C-reactive protein) has been associated with impaired lung function. A causal relationship would increase the value of CRP as both a diagnostic and therapeutic tool. We assessed the association between lung function parameters, circulating CRP and CRP polymorphisms using Mendelian randomization in efforts to attribute causality to known associations. Spirometric parameters of FEV1 (forced expiratory volume in 1 s) and FVC (forced vital capacity) were determined in 2173 men participating in the Caerphilly Prospective Study. Lung function measures on 1021 participants were available at follow-up (mean, 16.8 years later). Serum CRP levels were measured at baseline, and three CRP polymorphisms were analysed. Haplotype analysis was performed. Serum CRP levels at baseline were inversely associated with contemporaneous FEV1 and FVC as well as at follow-up (P<0.001) even after adjustment for conventional confounders. Serum CRP was associated with FEV1 decline (P=0.04). All three CRP polymorphisms (rs1800947, rs1130864 and rs1205) predicted serum CRP; however, there were no clear associations of the polymorphisms or haplotypes with lung function or with lung function decline. In conclusion, serum CRP was associated with lung function cross-sectionally; however, CRP polymorphisms were not associated with lung function or decline, suggesting that the CRP-lung function relationship is due to reverse causality, an unmeasured confounding factor or only has a modest causal effect.
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Genetic variants associated with Von Willebrand factor levels in healthy men and women identified using the HumanCVD BeadChip.
Ann. Hum. Genet.
PUBLISHED: 04-28-2011
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We have used the gene-centric Illumina HumanCVD BeadChip to identify common genetic determinants of Von Willebrand factor (vWF) levels in healthy men and women. The Whitehall II (WHII) study (n= 5592) and the British Womens Heart and Health Study (BWHHS) (n= 3445) were genotyped using the HumanCVD BeadChip. Replication was conducted in the British Regional Heart Study (n= 3897) and 1958 Birth Cohort (n= 5048). We identified 48 single nucleotide polymorphisms (SNPs) in four genes/regions associated with vWF at P < 10(-4) . These included 19 SNPs at the ABO blood group locus with the lead variant being rs657152 (P= 9.7 × 10(-233) ). The lead variant in the 24 VWF SNPs was rs1063856 (P= 2.3 × 10(-20) ). SNPs at ESR1 (rs6909023) and NRG1(rs1685103) showed modest associations with vWF, but these were not confirmed in a meta-analysis. Using variable selection, five SNPs at the locus for ABO and two for VWF were found to have independent associations with vWF levels. After adjustment for age and gender, the selected ABO SNPs explained 15% and the VWF SNPs an additional 2% of the variance in vWF levels. Individuals at opposite tails of the additive seven SNP allele score exhibited substantial differences in vWF levels. These data demonstrate that multiple common alleles with small effects make, in combination, important contributions to individual differences in vWF levels.
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Genome-wide association and large-scale follow up identifies 16 new loci influencing lung function.
María Soler Artigas, Daan W Loth, Louise V Wain, Sina A Gharib, Ma'en Obeidat, Wenbo Tang, Guangju Zhai, Jing Hua Zhao, Albert Vernon Smith, Jennifer E Huffman, Eva Albrecht, Catherine M Jackson, David M Evans, Gemma Cadby, Myriam Fornage, Ani Manichaikul, Lorna M Lopez, Toby Johnson, Melinda C Aldrich, Thor Aspelund, Inês Barroso, Harry Campbell, Patricia A Cassano, David J Couper, Gudny Eiriksdottir, Nora Franceschini, Melissa Garcia, Christian Gieger, Gauti Kjartan Gislason, Ivica Grković, Christopher J Hammond, Dana B Hancock, Tamara B Harris, Adaikalavan Ramasamy, Susan R Heckbert, Markku Heliövaara, Georg Homuth, Pirro G Hysi, Alan L James, Stipan Janković, Bonnie R Joubert, Stefan Karrasch, Norman Klopp, Beate Koch, Stephen B Kritchevsky, Lenore J Launer, Yongmei Liu, Laura R Loehr, Kurt Lohman, Ruth J F Loos, Thomas Lumley, Khalid A Al Balushi, Wei Q Ang, R Graham Barr, John Beilby, John D Blakey, Mladen Boban, Vesna Boraska, Jonas Brisman, John R Britton, Guy G Brusselle, Cyrus Cooper, Ivan Curjuric, Santosh Dahgam, Ian J Deary, Shah Ebrahim, Mark Eijgelsheim, Clyde Francks, Darya Gaysina, Raquel Granell, Xiangjun Gu, John L Hankinson, Rebecca Hardy, Sarah E Harris, John Henderson, Amanda Henry, Aroon D Hingorani, Albert Hofman, Patrick G Holt, Jennie Hui, Michael L Hunter, Medea Imboden, Karen A Jameson, Shona M Kerr, Ivana Kolčić, Florian Kronenberg, Jason Z Liu, Jonathan Marchini, Tricia McKeever, Andrew D Morris, Anna-Carin Olin, David J Porteous, Dirkje S Postma, Stephen S Rich, Susan M Ring, Fernando Rivadeneira, Thierry Rochat, Avan Aihie Sayer, Ian Sayers, Peter D Sly, George Davey Smith, Akshay Sood, John M Starr, André G Uitterlinden, Judith M Vonk, S Goya Wannamethee, Peter H Whincup, Cisca Wijmenga, O Dale Williams, Andrew Wong, Massimo Mangino, Kristin D Marciante, Wendy L McArdle, Bernd Meibohm, Alanna C Morrison, Kari E North, Ernst Omenaas, Lyle J Palmer, Kirsi H Pietiläinen, Isabelle Pin, Ozren Pola Sbreve Ek, Anneli Pouta, Bruce M Psaty, Anna-Liisa Hartikainen, Taina Rantanen, Samuli Ripatti, Jerome I Rotter, Igor Rudan, Alicja R Rudnicka, Holger Schulz, So-Youn Shin, Tim D Spector, Ida Surakka, Veronique Vitart, Henry Völzke, Nicholas J Wareham, Nicole M Warrington, H-Erich Wichmann, Sarah H Wild, Jemma B Wilk, Matthias Wjst, Alan F Wright, Lina Zgaga, Tatijana Zemunik, Craig E Pennell, Fredrik Nyberg, Diana Kuh, John W Holloway, H Marike Boezen, Debbie A Lawlor, Richard W Morris, Nicole Probst-Hensch, , Jaakko Kaprio, James F Wilson, Caroline Hayward, Mika Kähönen, Joachim Heinrich, Arthur W Musk, Deborah L Jarvis, Sven Gläser, Marjo-Riitta Järvelin, Bruno H Ch Stricker, Paul Elliott, George T O'Connor, David P Strachan, Stephanie J London, Ian P Hall, Vilmundur Gudnason, Martin D Tobin.
Nat. Genet.
PUBLISHED: 04-20-2011
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Pulmonary function measures reflect respiratory health and are used in the diagnosis of chronic obstructive pulmonary disease. We tested genome-wide association with forced expiratory volume in 1 second and the ratio of forced expiratory volume in 1 second to forced vital capacity in 48,201 individuals of European ancestry with follow up of the top associations in up to an additional 46,411 individuals. We identified new regions showing association (combined P < 5 × 10(-8)) with pulmonary function in or near MFAP2, TGFB2, HDAC4, RARB, MECOM (also known as EVI1), SPATA9, ARMC2, NCR3, ZKSCAN3, CDC123, C10orf11, LRP1, CCDC38, MMP15, CFDP1 and KCNE2. Identification of these 16 new loci may provide insight into the molecular mechanisms regulating pulmonary function and into molecular targets for future therapy to alleviate reduced lung function.
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Genome-wide association study identifies four loci associated with eruption of permanent teeth.
PLoS Genet.
PUBLISHED: 04-18-2011
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The sequence and timing of permanent tooth eruption is thought to be highly heritable and can have important implications for the risk of malocclusion, crowding, and periodontal disease. We conducted a genome-wide association study of number of permanent teeth erupted between age 6 and 14 years, analyzed as age-adjusted standard deviation score averaged over multiple time points, based on childhood records for 5,104 women from the Danish National Birth Cohort. Four loci showed association at P<5×10(-8) and were replicated in four independent study groups from the United States and Denmark with a total of 3,762 individuals; all combined P-values were below 10(-11). Two loci agreed with previous findings in primary tooth eruption and were also known to influence height and breast cancer, respectively. The two other loci pointed to genomic regions without any previous significant genome-wide association study results. The intronic SNP rs7924176 in ADK could be linked to gene expression in monocytes. The combined effect of the four genetic variants was most pronounced between age 10 and 12 years, where children with 6 to 8 delayed tooth eruption alleles had on average 3.5 (95% confidence interval: 2.9-4.1) fewer permanent teeth than children with 0 or 1 of these alleles.
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Genome-wide population-based association study of extremely overweight young adults--the GOYA study.
PLoS ONE
PUBLISHED: 04-06-2011
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Thirty-two common variants associated with body mass index (BMI) have been identified in genome-wide association studies, explaining ?1.45% of BMI variation in general population cohorts. We performed a genome-wide association study in a sample of young adults enriched for extremely overweight individuals. We aimed to identify new loci associated with BMI and to ascertain whether using an extreme sampling design would identify the variants known to be associated with BMI in general populations.
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