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REFERENCE VALUES FOR LEPTIN, CORTISOL, INSULIN AND GLUCOSE, AMONG EUROPEAN ADOLESCENTS AND THEIR ASSOCIATION WITH ADIPOSITY: THE HELENA STUDY.
Nutr Hosp
PUBLISHED: 11-04-2014
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Adequate concentrations of leptin, cortisol, and insulin are important for a suitable metabolism and development during adolescence. These hormones jointly with glucose play a major role in fat metabolism and development of childhood obesity. Our main objective was to quantify biomarkers as leptin, cortisol, insulin and glucose status in European adolescents to contribute to establish reference ranges.
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Infrequent stools in exclusively breastfed infants.
Breastfeed Med
PUBLISHED: 09-22-2014
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Abstract Background: Few data are available on the number of stools in exclusively breastfed infants. Two studies aimed to assess the stool pattern in exclusively breastfed infants and to evaluate the reactions of mothers in the case of infrequent stools and the decisions of healthcare providers.
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Reliability of health-related physical fitness tests in adolescents: the MOVE Program.
Clin Physiol Funct Imaging
PUBLISHED: 08-13-2014
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The aim was to examine the reliability of health-related physical fitness tests that were used in a French health promotion program 'Move…A priority for your health'. Participants were 174 French youth (88 children and 86 adolescents) aged 8·2-16·2 years. Aerobic fitness, muscular strength, speed and flexibility were tested using 20-m shuttle run test, ½ mile run test, basketball throw, standing long jump, shoulder stretch and 20/30/50-m sprint tests. Reliability was calculated for the basketball throw, standing long jump, shoulder stretch and sprint tests. The tests were performed two times, 1 week apart on the same day of the week. Reliability was examined with intraclass correlation coefficients (ICCs) and Bland-Altman analysis. With the exception of the ½ mile run test, which resulted in moderate agreement (0·66), all tests had high reliability. ICCs were 0·97, 0·93, 0·91 and 0·93 for the sprint test, basketball throw, shoulder stretch and the standing long jump, respectively. The differences obtained between the first and the second trial were non-significant. Results from this study indicate that the BOUGE health-related physical fitness battery, administrated by physical education teachers, was reliable for measuring health-related components of fitness in children and adolescents in a school setting.
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Technical variability of the Vivago® wrist-worn accelerometer.
J Sports Sci
PUBLISHED: 05-19-2014
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The aim was to assess the technical variability of a new wrist-worn accelerometer under controlled conditions with a shaker device and during normal daily physical activities (PAs). In the first experiment, 10 wrist-worn accelerometers (Vivago(®) Wellness, Paris, France) were attached to the shaker device. Variability was tested at five shaking frequencies (1.1, 2.1, 3.1, 4.1, and 10 Hz) for 10 min at each frequency. In the second experiment, 21 participants wore wrist-worn accelerometers and performed six consecutive 10-min periods of activity at increasing levels of intensity from sedentary to vigorous. Results from the first experiment show a modest inter- and intra-instrument reliability at low frequencies and that reliability improved as frequency increased. The inter-instrument coefficient of variation (CV) was 2.6-18.3%. The intra-instrument CV was 4.1-23.2%. Variability was similar in the second experiment with a CV inversely related to PA intensity. The inter- and intra-instrument CV varied from 24.2% and 19.9% for sedentary activities to 3.7% and 4.3% for vigorous PA, respectively. Results suggest that reliability was higher at high intensities, corresponding to moderate and vigorous PA, intensities generally recommended for public health purposes.
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Associations of early life and sociodemographic factors with menarcheal age in European adolescents.
Eur. J. Pediatr.
PUBLISHED: 04-01-2014
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Early menarche has been associated with adult overweight, cardiovascular risk factors, and other diseases. Little is known about the determinants of menarcheal age (MA). Therefore, the main aim of this study was to examine the associations between early life programming factors and menarcheal age in European adolescents. Secondly, the influence of sociodemographical factors on menarcheal age was also studied. A total of 1,069 European girls from the HELENA cross-sectional study, aged 12.5-17.5 years, were included in this study. Using multilevel linear regression models, a possible association between birth weight and length, ponderal index at birth, gestational age, duration of exclusive breastfeeding, and menarcheal age was examined. Associations between geographical gradient, number of siblings, physical activity (PA), dietary factors, and menarcheal age were also examined. After adjustment, menarcheal age was positively associated with birth weight and length (p?=?0.01 and p?=?0.01). Conclusion: These findings confirm that birth weight and length may have a programming effect on menarcheal age. Next to this finding, sociodemographic factors were not associated with menarcheal age.
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Health inequalities in urban adolescents: role of physical activity, diet, and genetics.
Pediatrics
PUBLISHED: 03-17-2014
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Coordinated European projects relying on standardized methods are needed to identify health inequalities across Europe. This study aimed to compare fitness, fatness, and cardiometabolic risk between urban adolescents from the south and center-north of Europe and to explore whether physical activity (PA) and other factors might explain these differences.
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Seasonal variation in physical activity and sedentary time in different European regions. The HELENA study.
J Sports Sci
PUBLISHED: 09-20-2013
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This report aims (1) to examine the association between seasonality and physical activity (PA) and sedentary time in European adolescents and (2) to investigate whether this association was influenced by geographical location (Central-North versus South of Europe), which implies more or less extreme weather and daylight hours. Valid data on PA, sedentary time and seasonality were obtained in 2173 adolescents (1175 females; 12.5-17.5 years) included in this study. Physical activity and sedentary time were measured by accelerometers. ANCOVA was conducted to analyse the differences in PA and sedentary time across seasons. Results showed that girls had lower levels of moderate to vigorous PA (MVPA) and average PA, and spent more time in sedentary activities in winter compared with spring (all P < 0.05). Stratified analyses showed differences in PA and sedentary time between winter and spring in European girls from Central-North of Europe (P < 0.05 for sedentary time). There were no differences between PA and sedentary time across seasonality in boys. In conclusion, winter is related with less time spent in MVPA, lower average PA and higher time spent in sedentary activities in European adolescent girls, compared with spring. These differences seem to mainly occur in Central-North Europe.
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Strategies in intervention programmes for obese youth: implication of the age and the type of physical activities.
Clin Physiol Funct Imaging
PUBLISHED: 09-10-2013
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The aim of this study was to assess the effects of age and type of physical activity on anthropometric measures of obese youth participating in an intervention programme. Subjects included 37 obese children (12·5 ± 2·9 years). The programme consisted of a unique programme of physical activity and health education. Assessments included body mass index (BMI), body composition and ability to perform sport activities. Paired t-tests were used to assess the effects of intervention, and chi square was used to assess interaction between measures. Findings suggest significant decrease in Z-scores of BMI and an improvement in the ability to perform sport activities (P<0·05). The effectiveness of the programme has more impact on children than adolescents (P<0·05). Improvements were greater in team versus net sports (P<0·05). Results show that intervention strategies have to be different according to the age to have a favourable effect on anthropometric characteristic and the consequences of obesity childhood and adulthood. The findings suggest that the intervention programme was of greater benefit for children than adolescents.
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How many days of accelerometer monitoring predict weekly physical activity behaviour in obese youth?
Clin Physiol Funct Imaging
PUBLISHED: 08-26-2013
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The aim of this study was to determine the type and the number of accelerometer monitoring days needed to predict weekly sedentary behaviour and physical activity in obese youth. Fifty-three obese youth wore a triaxial accelerometer for 7 days to measure physical activity in free-living conditions. Analyses of variance for repeated measures, Intraclass coefficient (ICC) and regression linear analyses were used. Obese youth spent significantly less time in physical activity on weekends or free days compared with school days. ICC analyses indicated a minimum of 2 days is needed to estimate physical activity behaviour. ICC were 0·80 between weekly physical activity and weekdays and 0·92 between physical activity and weekend days. The model has to include a weekday and a weekend day. Using any combination of one weekday and one weekend day, the percentage of variance explained is >90%. Results indicate that 2 days of monitoring are needed to estimate the weekly physical activity behaviour in obese youth with an accelerometer. Our results also showed the importance of taking into consideration school day versus free day and weekday versus weekend day in assessing physical activity in obese youth.
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Impact of the choice of threshold on physical activity patterns in free living conditions among adolescents measured using a uniaxial accelerometer: The HELENA study.
J Sports Sci
PUBLISHED: 07-26-2013
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Abstract The aim of this study was to assess the impact of the choice of threshold on physical activity patterns measured in adolescents under free living conditions (FLC) using a uniaxial accelerometer. The study comprised 2043 adolescents (12.5-17.5 years) participating in the HELENA Study. Participants wore a uniaxial accelerometer for 7 days. The PA patterns were assessed using thresholds determined from six different studies. For each of the thresholds used, the number of adolescents fulfilling the recommendation of 60 min of moderate to vigorous PA (MVPA) per day was also calculated. A significant difference was found between thresholds regardless of the activity level: differences of 38%, 207%, 136%, and 2780% for sedentary, light, moderate, and vigorous intensity PA, respectively (P < 0.001). Time of MVPA varied between methods from 25.3 to 55.2 min · day(-1). The number of adolescents fulfilling the recommendation varied from 5.9% to 37% according to the thresholds used. The kappa coefficient for concordance in the assessment of the number of adolescents achieving the PA recommendations was generally low. The definition of the threshold for PA intensity may considerably affect the PA patterns in FLC when assessed using a uniaxial accelerometer and the number of participants fulfilling the recommendations.
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Concurrent validity of the modified International Physical Activity Questionnaire for French obese adolescents.
Percept Mot Skills
PUBLISHED: 07-09-2013
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Physical activity is an important component of a healthy lifestyle. Evaluating and promoting this activity warrants careful attention, particularly in the context of preventing obesity associated with low physical activity. The aim of the present study was to assess the concurrent validity of a modified, long, self-administered version of the International Physical Activity Questionnaire (IPAQ) using triaxial accelerometry in 56 youth with obesity. The participants physical activity was measured with an RT3 accelerometer (objective measure) and with the International Physical Activity Questionnaire for Adolescents (IPAQ-A; subjective measure). Although the two methods were correlated strongly (r = .84), there was a significant difference between the two methods. The participants subjective ratings on the IPAQ-A overestimated the objective measure. Although activity questionnaires are simple and widely used in assessing physical activity, alternative methods should be used when measuring physical activity in youth with obesity.
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Dietary and lifestyle quality indices with/without physical activity and markers of insulin resistance in European adolescents: the HELENA study.
Br. J. Nutr.
PUBLISHED: 04-19-2013
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Emerging data indicate that higher levels of insulin resistance (IR) are common among children and adolescents and are related to cardiometabolic risk; therefore, IR requires consideration early in life. In addition, there is a lack of conclusive evidence regarding the role of dietary nutrients on IR. The Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS) was conducted in European adolescents aged 12·5–17·5 years. A total of 637 participants with valid homeostasis model assessment (HOMA) index data and who completed at least a 2 d 24 h dietary recall were included in the study (60% of the total HELENA-CSS sample). There were two dietary indices calculated, with the only difference between them being the inclusion or not of physical activity (PA). Markers of IR such as HOMA and the quantitative insulin sensitivity check index (QUICKI) were calculated. Pubertal status, BMI and cardiorespiratory fitness (CRF) were measured as potential confounders. The dietary index including PA was inversely associated with HOMA and directly with the QUICKI in females, but not in males, after adjusting for pubertal status, centre, BMI and CRF. In conclusion, the present study indicates that considering PA as part of the dietary index is of relevance as the resulted index is inversely related to IR independently of potential confounders including CRF. Overall, these findings suggest that intervention studies aimed at preventing IR in young people should focus on increasing the quality of the diet and also on including an optimal PA level in healthy adolescents.
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Add-on omalizumab in children with severe allergic asthma: a 1-year real life survey.
Eur. Respir. J.
PUBLISHED: 03-21-2013
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Omalizumab has been shown to reduce exacerbation rates in moderate to severe allergic asthma. Our aim was to evaluate omalizumab efficacy and safety in a real-life setting in severe asthmatic children. 104 children (aged 6-18 years), followed up in paediatric pulmonary tertiary care centres, were included at the beginning of omalizumab treatment. Asthma control levels, exacerbations, inhaled corticosteroid dose, lung function and adverse events were evaluated over 1 year. Children were characterised by allergic sensitisation to three or more allergens (66%), high IgE levels (mean 1125 kU · L(-1)), high rate of exacerbations (4.4 per year) and healthcare use during the previous year, and high inhaled corticosteroid dose (mean 703 ?g equivalent fluticasone per day). Asthma control levels defined as good, partial or poor, improved from 0%, 18% and 82% at entry to 53%, 30% and 17% at week 20, and to 67%, 25% and 8% at week 52, respectively (p<0.0001). Exacerbation and hospitalisation rates dropped by 72% and 88.5%, respectively. At 12 months, forced expiratory volume in 1 s improved by 4.9% (p=0.023), and inhaled corticosteroid dose decreased by 30% (p<0.001). Six patients stopped omalizumab for related significant adverse events. Omalizumab improved asthma control in children with severe allergic asthma and was generally well tolerated. The observed benefit was greater than that reported in clinical trials.
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Mechanical ventilatory constraints during incremental exercise in healthy and cystic fibrosis children.
Pediatr. Pulmonol.
PUBLISHED: 03-13-2013
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AIM: To analyze breathing pattern and mechanical ventilatory constraints during incremental exercise in healthy and cystic fibrosis (CF) children. METHODS: Thirteen healthy children and 6 children with cystic fibrosis volunteered to perform an incremental test on a treadmill. Exercise tidal flow/volume loops were plotted every minute within a maximal flow/volume loop (MFVL). Expiratory flow limitation (expFL expressed in %Vt) was evaluated and end-expiratory and end-inspiratory lung volumes (EELV and EILV) were estimated from expiratory reserve volume relative to vital capacity (ERV/FVC) and from inspiratory reserve volume relative to vital capacity (IRV/FVC). RESULTS: During the incremental exercise, expFL was first observed at 40% of maximal aerobic speed in both groups. At maximal exercise, 46% of healthy children and 83% of CF children presented expFL, without significant effect of cystic fibrosis on the severity of expFL. According to the two-way ANOVA results, both groups adopted similar breathing pattern and breathing strategies as no significant effect of CF has been revealed. But, according to one-way ANOVA results, a significant increase of ERV/FVC associated with a significant decrease of IRV/FVC from resting value shave been observed in healthy children at maximal exercise, but not in CF children. DISCUSSION: The hypothesis of this study was based on the assumption that mild cystic fibrosis could induce more frequent and more severe mechanical ventilatory constraints due to pulmonary impairment and breathing pattern disturbances. But, this study did not succeed to highlight an effect of mild cystic fibrosis on the mechanical ventilatory constraints (expFL and dynamic hyperinflation) that occur during an incremental exercise. This absence of effect could be due to the absence of an impact of the disease on spirometric data, breathing pattern regulation during exercise and breathing strategy. Pediatr Pulmonol. 2013 9999:XX-XX. © 2013 Wiley Periodicals, Inc.
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Nutrient intake of European adolescents: results of the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study.
Public Health Nutr
PUBLISHED: 03-08-2013
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OBJECTIVE: An adequate nutritional intake in childhood and adolescence is crucial for growth and the prevention of youth and adult obesity and nutrition-related morbidities. Improving nutrient intake in children and adolescents is of public health importance. The purpose of the present study was to describe and evaluate the nutrient intake in a European sample using the D-A-CH nutrient intake recommendations and the Nutritional Quality Index (NQI). DESIGN: The HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study is a cross-sectional study, the main objective of which is to obtain comparable data on a variety of nutritional and health-related parameters in adolescents aged 12·5-17·5 years. SETTING: Eight cities in Europe. SUBJECTS: The initial sample consisted of 3528 European adolescents. Among these, 1590 adolescents (54 % female) had sufficient and plausible dietary data on energy and nutrient intakes from two 24 h recalls using the HELENA-DIAT software. RESULTS: The intakes of most macronutrients, vitamins and minerals were in line with the D-A-CH recommendations. While the intakes of SFA and salt were too high, the intake of PUFA was too low. Furthermore, the intakes of vitamin D, folate, iodine and F were less than about 55 % of the recommendations. The median NQI was about 71 (of a maximum of 100). CONCLUSIONS: The intakes of most nutrients were adequate. However, further studies using suitable criteria to assess nutrient status are needed. Public health initiatives should educate children and adolescents regarding balanced food choices.
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Effect of child health status on parents allowing children to participate in pediatric research.
BMC Med Ethics
PUBLISHED: 02-12-2013
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To identify motivational factors linked to child health status that affected the likelihood of parents allowing their child to participate in pediatric research.
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More physically active and leaner adolescents have higher energy intake.
J. Pediatr.
PUBLISHED: 01-10-2013
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To test whether youths who engage in vigorous physical activity are more likely to have lean bodies while ingesting relatively large amounts of energy. For this purpose, we studied the associations of both physical activity and adiposity with energy intake in adolescents.
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European adolescents level of perceived stress is inversely related to their diet quality: the Healthy Lifestyle in Europe by Nutrition in Adolescence study.
Br. J. Nutr.
PUBLISHED: 11-04-2011
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As stress is hypothesised to influence dietary behaviour, the relationship between perceived stress and diet quality in European adolescents was investigated. Within the Healthy Lifestyle in Europe by Nutrition in Adolescence study, adolescents (n 704, aged 12-17 years) from schools in five European cities (Ghent, Stockholm, Zaragoza, Athens and Vienna) completed a 2 d 24 h dietary recall assessment and an Adolescent Stress Questionnaire. Measurements and information were taken on height, weight, pubertal stage, parental education level, the level of moderate-to-vigorous physical activity (MVPA) and sleep duration. The Diet Quality Index for Adolescents (DQI-A) was calculated from the dietary data, which comprised three components reflecting dietary diversity, quality and equilibrium. Hierarchical linear models were performed to investigate the relationship between the adolescents level of perceived stress and the DQI-A and its components, adjusting for relevant covariates (age, BMI z-score, pubertal stage and parental education). These models were additionally adjusted for MVPA or sleep duration. In both boys and girls, perceived stress was a significant independent negative predictor for their overall DQI-A. This inverse relationship was observed for all dietary components, except for dietary diversity in boys, and it was unaltered when additionally adjusted for MVPA or sleep duration. The observed inverse relationship between stress and diet quality within these European adolescents supports the hypothesis that stress influences dietary behaviour, thus emphasising the need for preventive stress-coping strategies for adolescents.
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New validated thresholds for various intensities of physical activity in adolescents using the Actigraph accelerometer.
Int J Rehabil Res
PUBLISHED: 09-09-2011
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The aim of this study was to determine and validate the new thresholds for various intensities of physical activity in adolescents using the Actigraph accelerometer. Sixty healthy participants aged 10-16 years were recruited. Forty participants participated in the calibration study whereas the others participated in the validation study. Accelerometer data, heart rate, and oxygen consumption were measured at nine levels of physical activity which varied in intensity: sedentary, light, moderate and vigorous. The activity categories and accelerometer counts were sedentary activity, 0-400 counts/min; light activity, 401-1900 counts/min; moderate activity, 1901-3918 counts/min; and vigorous activity, greater than 3918 counts/min, respectively. This study establishes new threshold values for various physical activities that can be used for population-based studies in adolescents.
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Physical activity, fitness, and serum leptin concentrations in adolescents.
J. Pediatr.
PUBLISHED: 08-09-2011
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To examine the association of physical activity and fitness with leptin concentrations in European adolescents, after taking into account several potential confounders including total body fat (TBF).
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Nutritional knowledge in European adolescents: results from the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study.
Public Health Nutr
PUBLISHED: 08-02-2011
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To build up sufficient knowledge of a healthy diet. Here, we report on the assessment of nutritional knowledge using a uniform method in a large sample of adolescents across Europe.
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Fitness and fatness are independently associated with markers of insulin resistance in European adolescents; the HELENA study.
Int J Pediatr Obes
PUBLISHED: 05-31-2011
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To examine the independent association of total and central body fat and cardiorespiratory fitness with markers of insulin resistance after controlling for several potential confounders in European adolescents participating in the HELENA-CSS (Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional) study.
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The effect of ponderal index at birth on the relationships between common LEP and LEPR polymorphisms and adiposity in adolescents.
Obesity (Silver Spring)
PUBLISHED: 04-21-2011
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This study examined the effect of ponderal index (PI) at birth on the relationships between eight common polymorphisms of the leptin (LEP) and leptin receptor (LEPR) genes and adiposity in adolescents. A total of 823 European adolescents (45.4% girls) aged 14.8 ± 1.4 years were genotyped for the LEP (rs2167270, rs12706832, rs10244329, rs2071045, and rs3828942) and LEPR (rs1137100, rs1137101, and rs8179183) polymorphisms. The PI was calculated from parental reports of birth weight and length. Fat mass index (FMI) was calculated. Analyses were adjusted for relevant confounders. An "adiposity-risk-allele score" based on genotypes at the three single-nucleotide polymorphisms (SNPs) associated with adolescents FMI in adolescents within the lower tertile of PI was calculated. The LEP rs10244329 and rs3828942 polymorphisms were associated with higher FMI only in adolescents within the lower PI tertile (+0.55 kg/m(2) per minor T allele, P = 0.040, and +0.58 kg/m(2) per major G allele, P = 0.028, respectively). The LEPR rs8179183 polymorphism was significantly associated with higher FMI in adolescents within the lower PI tertile (+0.87 kg/m(2) per minor C allele, P = 0.006). After correction for multiple comparisons, only the association between the LEPR rs8179183 and FMI persisted. However, each additional risk allele conferred 0.53 kg/m(2) greater FMI in adolescents within the lower tertile of PI (P = 0.008). In conclusion, our results suggest that those adolescents born with lower PI could be more vulnerable to the influence of the LEP rs10244329 and rs3828942 polymorphisms and LEPR rs8179183 polymorphism on total adiposity content. Due to the relatively small sample size, these findings should be replicated in further larger population samples.
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Socioeconomic status and bone mass in Spanish adolescents. The HELENA Study.
J Adolesc Health
PUBLISHED: 04-18-2011
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Socioeconomic status (SES) has been frequently associated with body composition, particularly fat mass and obesity. However, the SES-bone mass association is not clear. We aimed to evaluate the associations between different SES indicators (Family Affluence Scale, parental education, and occupation) and bone mineral content in Spanish adolescents.
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Objectively measured physical activity and sedentary time in European adolescents: the HELENA study.
Am. J. Epidemiol.
PUBLISHED: 04-05-2011
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The authors aim in this cross-sectional study was to characterize levels of objectively measured physical activity and sedentary time in adolescents from 9 European countries. The study comprised 2,200 European adolescents (1,184 girls) participating in the HELENA cross-sectional study (2006-2008). Physical activity was measured by accelerometry and was expressed as average intensity (counts/minute) and amount of time (minutes/day) spent engaging in moderate- to vigorous-intensity physical activity (MVPA). Time spent in sedentary behaviors was also objectively measured. Cardiorespiratory fitness was measured by means of the 20-m shuttle run test. Level of maternal education was reported by the adolescents. A higher proportion of boys (56.8% of boys vs. 27.5% of girls) met the physical activity recommendations of at least 60 minutes/day of MVPA. Adolescents spent most of the registered time in sedentary behaviors (9 hours/day, or 71% of the registered time). Both average intensity and MVPA were higher in adolescents with high cardiorespiratory fitness, and sedentary time was lower in the high-fitness group. There were no physical activity or sedentary time differences between maternal education categories. These data provide an objective measure of physical activity and amount of time spent in sedentary behaviors in a relatively large number of European adolescents.
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The International Fitness Scale (IFIS): usefulness of self-reported fitness in youth.
Int J Epidemiol
PUBLISHED: 03-24-2011
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We examined: (i) the usefulness of the International Fitness Scale (IFIS) to correctly rank adolescents into physical fitness levels; (ii) the capacity of the IFIS for predicting cardiovascular disease (CVD) risk; and (iii) the reliability of the IFIS in adolescents.
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Comparison of the IPAQ-A and actigraph in relation to VO2max among European adolescents: the HELENA study.
J Sci Med Sport
PUBLISHED: 02-19-2011
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The purpose was to compare data obtained from a modified, long, self-administered version of the International Physical Activity Questionnaire (IPAQ-A) with objective data obtained in parallel from Actigraph accelerometers, and VO(2)max in adolescents. The study comprised a total of 2018 adolescents (46% male) from ten European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study. Physical activity was assessed over seven consecutive days by accelerometry and expressed as min/day of moderate, vigorous, and moderate to vigorous (MVPA) physical activity (PA). PA was also assessed with the IPAQ-A. VO(2)max was estimated from a 20-m shuttle run test. Poor to fair correlations between the two methodologies were found for the whole study sample and when stratified by age and gender (r(s) = 0.08-0.26, p < 0.01). On average, the self-reported time spent in moderate PA was higher compared to the time measured with the accelerometer, while the differences between both instruments were less clear for vigorous intensity. Adolescents reporting high levels of PA (3rd tertile IPAQ-A) also showed higher levels of PA (accelerometers) in all the study variables (moderate, vigorous and MVPA), compared to adolescents reporting low PA (1st tertile IPAQ-A) (all p < 0.001). Both methods were moderately correlated with estimated VO(2)max. Within the HELENA-study, the IPAQ-A showed the modest comparability with the accelerometer data for assessing PA in each intensity level and was the highest for vigorous intensity. Both instruments are able to detect the adolescents with the highest cardio respiratory fitness, which are the most active adolescents.
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Comparison of mechanical ventilatory constraints between continuous and intermittent exercises in healthy prepubescent children.
Pediatr. Pulmonol.
PUBLISHED: 02-18-2011
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The aim of this study was to evaluate the occurrence and severity of mechanical ventilatory constraints in healthy prepubescent children during continuous and intermittent exercise.
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Effects of a multidisciplinary rehabilitation program on pediatric obesity: the CEMHaVi program.
Int J Rehabil Res
PUBLISHED: 02-15-2011
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The objective of this study is to assess the effects of the unique 1-year health-wellness program of exercise and health education for obese youth on body mass index (BMI) and blood pressure. The CEMHaVi program included 74 obese children. Participants, 19 girls and 18 boys, and controls, 17 girls and 20 boys, were assigned to treatment. The treatment participants were compared with a group who chose not to participate. Treatment consisted of a unique program of physical activity that emphasized playing games. Activity sessions were offered once per week, 2 h each session, for 12 months. Physical activity was complemented with health education. Controls received only the normal care of a physician in pediatrics. Physical and physiological measures were assessed before and after intervention. Findings of the study showed a significant difference in BMI between treatment and control participants (P<0.05). BMI decreased in the treatment group and increased in controls. There were no significant differences in blood pressure. In conclusion, results of the study suggest that a unique program of exercise and health education had beneficial effects on BMI in obese youth after 1 year. The feasibility of a beneficial lifestyle intervention program is encouraging.
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Relationship between self-reported dietary intake and physical activity levels among adolescents: the HELENA study.
Int J Behav Nutr Phys Act
PUBLISHED: 02-06-2011
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Evidence suggests possible synergetic effects of multiple lifestyle behaviors on health risks like obesity and other health outcomes. Therefore it is important to investigate associations between dietary and physical activity behavior, the two most important lifestyle behaviors influencing our energy balance and body composition. The objective of the present study is to describe the relationship between energy, nutrient and food intake and the physical activity level among a large group of European adolescents.
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Breastfeeding in infancy is not associated with inflammatory status in healthy adolescents.
J. Nutr.
PUBLISHED: 01-19-2011
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It has been suggested that breast-feeding (BF) may be associated with a decreased risk of cardiovascular disease in adulthood. A low-grade inflammation is associated with an increased risk of cardiovascular disease, even in apparently healthy children. The objective of this study was to assess the potential modulating effect of BF on the inflammatory status of healthy adolescents. Information on BF (duration) was obtained from parental records in 484 of 1040 healthy European urban adolescents (56.4% females) that had a blood sample obtained as part of the Healthy Lifestyle in Europe by Nutrition and Adolescence study. Blood serum inflammatory markers were measured, including high sensitivity C-reactive protein, complement factors 3 and 4, ceruloplasmin, adhesion molecules (L-selectin and soluble endothelial selectin, soluble vascular cell adhesion molecule 1, and intercellular adhesion molecule 1), cytokines, TGF?1, and white blood cells. After univariate analysis, a propensity score, including the potential confounding factors, was computed and used to assess the association between BF and selected inflammatory markers. BF was not significantly associated with any of the selected inflammatory markers after adjustment for gender and propensity score. In our study, BF was not associated with low-grade inflammatory status in healthy adolescents, suggesting that the potential cardiovascular benefits of BF are related to other mechanisms than modulation of inflammation or might become relevant at a later age. Groups at high risk for cardiovascular disease should be a target for further research concerning the effects of BF.
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Excessive sedentary time and low cardiorespiratory fitness in European adolescents: the HELENA study.
Arch. Dis. Child.
PUBLISHED: 01-10-2011
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The aims of this study were to examine what amount of sedentary time is associated with low cardiorespiratory fitness (CRF) in adolescents and whether this association is independent of physical activity.
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Associations between common genetic polymorphisms in the liver X receptor alpha and its target genes with the serum HDL-cholesterol concentration in adolescents of the HELENA Study.
Atherosclerosis
PUBLISHED: 01-03-2011
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Genetic variability in the NR1H3 gene (encoding LXR?) and in several of its target genes is associated with serum HDL-cholesterol (HDL-C) concentrations. We sought to assess if these associations could be detected in adolescents.
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Adolescents physical activity levels and relatives physical activity engagement and encouragement: the HELENA study.
Eur J Public Health
PUBLISHED: 10-08-2010
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The aim of this article is to examine the association between adolescents physical activity (PA) levels and their relatives (father, mother, brothers, sisters and best friend) PA engagement and encouragement.
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Recommended levels and intensities of physical activity to avoid low-cardiorespiratory fitness in European adolescents: The HELENA study.
Am. J. Hum. Biol.
PUBLISHED: 08-20-2010
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The purpose of this study was to determine the sex-specific physical activity (PA) intensity thresholds that best discriminate between unhealthy/healthy cardiorespiratory fitness (CRF).
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Effect of multifibre mixture with prebiotic components on bifidobacteria and stool pH in tube-fed children.
Br. J. Nutr.
PUBLISHED: 08-06-2010
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The objective of the present study was to evaluate the effect of a paediatric tube feed supplemented with a multifibre mixture on the gut microbiota and nutritional and micronutrient status of children on long-term enteral nutrition (EN). A randomised, controlled, double-blind, cross-over trial (2 × 3 months) with a washout period of 1 month was carried out. Twenty-seven children (80% neurologically impaired) aged 11.9 (SD 3.9) years, on long-term EN (4.8 (SD 3.9) years) were recruited. The analyses of the childrens faecal pH, microbiota along with anthropometric measures, bowel movements and markers of blood micronutrient status were made. Twenty children completed the study. A significant increase in the proportion of stool bifidobacteria (+16.6%, P < 0.05) was observed during the multifibre period than during the fibre-free period, together with a significant reduction in stool pH (P < 0.001). Stool frequency and consistency as well as growth did not differ between the two periods. There was a significant increase (P < 0.05) in plasma ferritin at the end of the fibre-free period, but plasma ferritin levels remained within normal ranges during both periods. No diet effects on other blood parameters were observed. In conclusion, addition of a multifibre mixture with prebiotic components to paediatric EN is well tolerated, promotes bifidobacteria and reduces stool pH, indicating an improved gut health.
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The CEMHaVi program: control, evaluation, and modification of lifestyles in obese youth.
J Cardiopulm Rehabil Prev
PUBLISHED: 03-02-2010
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Obesity in children has increased in recent years. Many studies with differing methodologies have been undertaken to treat obesity. The Control, Evaluation, and Modification of Lifestyles in Obese Youth (CEMHaVi) program is a unique 2-year health-wellness program of physical activity and health education for obese youth. Findings of this study represent results at 1-year follow-up. The purpose of this study was to evaluate the effects of the CEMHaVi program.
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Reliability of the RT3 accelerometer for measurement of physical activity in adolescents.
J Sports Sci
PUBLISHED: 02-23-2010
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The aim of this study was to assess the reliability of the RT3 accelerometer under conditions of normal physical activity. Sixty healthy individuals (30 boys, 30 girls) aged 10-16 years wore two accelerometers while performing different structured physical activities. The accelerometers were synchronized and data were recorded every minute during nine 15-min sessions of physical activity that varied in intensity from sedentary (watching television, playing video games) to vigorous (running on a treadmill at different speeds). Intra-instrument coefficients of variation (CV) were assessed using the formula CV = standard deviation of the measure x 100/mean of the measure. The intra-instrument coefficient of variation was higher for sedentary (17%) and light activity (16.2%) than moderate (9.3%) and vigorous activity (6.6%). These results confirmed the poor reliability of the RT3 for activity of low magnitude and frequency that was demonstrated in studies using a shaker.
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Calibration of the RT3 accelerometer for various patterns of physical activity in children and adolescents.
J Sports Sci
PUBLISHED: 02-23-2010
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The aim of this study was to determine thresholds for various intensities of physical activity in children and adolescents using the RT3 accelerometer. Forty healthy participants aged 10-16 years were recruited to the study. To validate the RT3 accelerometer data, an independent sample of 20 children and adolescents aged 10-16 years performed the same activities. Accelerometer data, heart rate, and oxygen consumption were measured at nine levels of physical activity, which varied in intensity: sedentary, light, moderate, and vigorous. Age and sex did not affect thresholds. The activity categories and accelerometer counts were: sedentary activity, 0-40 counts x min(-1); light activity, 41-950 counts x min(-1); moderate activity, 951-3410 counts x min(-1); and vigorous activity, >3410 counts x min(-1), respectively. These thresholds were considered valid as the difference between threshold values obtained using two independent groups of children was not significant. This study has established threshold values for various physical activities and enables the RT3 accelerometer to be used to quantify the duration of various levels of activity in adolescents under free-living conditions.
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Correspondences between continuous and intermittent exercises intensities in healthy prepubescent children.
Eur. J. Appl. Physiol.
PUBLISHED: 11-10-2009
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The aim of this article is to determine correspondences between three levels of continuous and intermittent exercise (CE and IE, respectively) in terms of steady-state oxygen uptake (VO(2SS)) and heart rate (HR) in children. Fourteen healthy children performed seven exercises on a treadmill: one graded test for the determination of maximal aerobic speed (MAS), three CE at 60, 70 and 80% of MAS (CE60, CE70 and CE80) and three IE (alternating 15 s of exercise intercepted with 15 s of passive recovery) at 90, 100 and 110% of MAS (IE90, IE100 and IE110). Mean VO(2SS) and mean HR were determined for both continuous and intermittent exercises. For comparison, three associations were designed: CE60 versus IE90, CE70 versus IE100 and CE80 versus IE110. No VO(2SS) difference was observed for CE60 versus IE90 and CE70 versus IE100 whereas a significant difference (P < 0.01) was found for CE80 versus IE110 (1.36 +/- 0.45 vs. 1.19 +/- 0.38 L min(-1), respectively). Significant linear regressions were found for the three CE versus IE associations for VO(2SS) (0.60 < r (2) < 0.99, P < 0.05). For the three associations, mean HR presented no significant difference. Only one significant relation was found for CE80 versus IE110 association (r(2) = 0.49, P < 0.05). Correspondences between CE and IE intensities are possible in terms of VO(2SS) whatever the level of exercise; even if for high intensities, VO(2SS) was higher during CE. These results demonstrated that it is possible to diversify the exercise modality while conserving exercise individualization.
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Associations between common genetic polymorphisms in angiopoietin-like proteins 3 and 4 and lipid metabolism and adiposity in European adolescents and adults.
J. Clin. Endocrinol. Metab.
PUBLISHED: 11-04-2009
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Plasma-borne angiopoietin-like proteins (ANGPTL) act as endocrine factors on their target tissues. Because ANGPTL3 and ANGPTL4 play important roles in lipid metabolism and the regulation of adiposity in mice, we hypothesized that genetic variability at the ANGPTL3 and ANGPTL4 genes loci might influence lipid metabolism and fat deposition in humans.
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Breast-feeding modulates the influence of the peroxisome proliferator-activated receptor-gamma (PPARG2) Pro12Ala polymorphism on adiposity in adolescents: The Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) cross-sectional study.
Diabetes Care
PUBLISHED: 10-21-2009
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The peroxisome proliferator-activated receptor-gamma2 (PPARG2) Pro12Ala polymorphism has been associated with a higher BMI and a lower risk of type 2 diabetes in adulthood. The association between adiposity and PPARG variants can be influenced by environmental factors such as early growth, dietary fat, and (as recently shown) breast-feeding. The objectives of this study were to assess 1) the influence of the PPARG2 Pro12Ala polymorphism on adiposity markers in adolescents and 2) a possible modulating effect of breast-feeding on these associations.
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Equivalence of accelerometer data for walking and running: treadmill versus on land.
J Sports Sci
PUBLISHED: 05-09-2009
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The aim of this study was to compare equivalence and agreement of physical activity output data collected by a Research Tri-axial accelerometer (R3T) during walking and running on a treadmill versus on land. Fifty healthy volunteers, 35 males (age 21.9 +/- 1.8 years) and 15 females (age 21.6 +/- 0.7 years), underwent a series of tests on a treadmill and on land with the order of testing administered randomly. Each participant walked for 10 min at 4 km x h(-1) and 6 km x h(-1), and ran at 8 km x h(-1) and 10 km x h(-1), with the same accelerometer. Analysis of output data was assessed by two statistical tests: the equivalence test and Bland and Altman method. Mean differences for walking were 41.2 +/- 129.8 counts per minute and -68.8 +/- 173.15 counts per minute at 4 km . h(-1) and km x h(-1), respectively. Mean differences for running were 19.1 +/- 253.20 counts per minute and 38.9 +/- 270.2 counts per minute at 8 km x h(-1) and 10 km x h(-1), respectively. The physical activity output data from the treadmill were higher by an average of 3.5% than the data collected on land. The differences obtained between the treadmill and on land were small and non-significant. The equivalence test showed that output data from the treadmill versus on land were equivalent (P < 0.05). The Bland and Altman method showed good agreement between the counts obtained on the treadmill and on land (P < 0.05). In conclusion, physical activity output data were similar as measured by the RT3 accelerometer on a treadmill and on land. The findings suggest that the RT3 may be used in a laboratory and extrapolated to data obtained on land.
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Changes in lung function in young cystic fibrosis patients between two courses of intravenous antibiotics against Pseudomonas aeruginosa.
Pediatr. Pulmonol.
PUBLISHED: 04-11-2009
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Repeated intravenous antibiotic therapy (IVAT) against chronic pulmonary infection with Pseudomonas aeruginosa is often necessary in cystic fibrosis patients (CF). The aim of this study was to monitor kinetics of degradation of pulmonary and nutritional status after IVAT in CF patients.
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Influence of esophageal pH recording on physical activity in children.
J. Pediatr. Gastroenterol. Nutr.
PUBLISHED: 03-31-2009
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Twenty-four-hour pH-metry represents the gold standard for the diagnosis of gastroesophageal reflux. Ambulatory esophageal pH recording provides a better reflection of occurrences under normal domestic living conditions, but it may influence physical activity. The aim of this study was to assess the influence of ambulatory esophageal pH recording on physical activity in children.
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Genetic and molecular insights into the role of PROX1 in glucose metabolism.
Diabetes
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Genome-wide association studies have shown that the rs340874 single nucleotide polymorphism (SNP) in PROX1 is a genetic susceptibility factor for type 2 diabetes. We conducted genetic and molecular studies to better understand the role of PROX1 in type 2 diabetes. We assessed the impact of the whole common genetic variability of PROX1 (80 SNPs) on type 2 diabetes-related biochemical traits in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study (n = 1,155). Three SNPs (rs340838, rs340837, and rs340836) were significantly associated with fasting plasma insulin levels (P ? 0.00295). We evaluated the impact of nine PROX1 SNPs (the three insulin-associated SNPs plus six SNPs in strong linkage disequilibrium) on luciferase reporter gene expression. The insulin-lowering alleles of rs340874, rs340873, and rs340835 were associated with lower luciferase activity in MIN6 and HepG2 cells (except for rs340874, which was in HepG2 cells only). Electrophoretic mobility shift assays indicated that specific nuclear protein bindings occur at the three SNPs in HepG2 cells, with allele-binding differences for rs340874. We also showed that the knockdown of Prox1 expression by small interfering RNAs in INS-1E cells resulted in a 1.7-fold reduction in glucose-stimulated insulin secretion. All together, we propose that reduced expression of PROX1 by cis-regulatory variants results in altered ?-cell insulin secretion and thereby confers susceptibility to type 2 diabetes.
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Validation of the Diet Quality Index for Adolescents by comparison with biomarkers, nutrient and food intakes: the HELENA study.
Br. J. Nutr.
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Food-based dietary guidelines (FBDG) aim to address the nutritional requirements at population level in order to prevent diseases and promote a healthy lifestyle. Diet quality indices can be used to assess the compliance with these FBDG. The present study aimed to investigate whether the newly developed Diet Quality Index for Adolescents (DQI-A) is a good surrogate measure for adherence to FBDG, and whether adherence to these FBDG effectively leads to better nutrient intakes and nutritional biomarkers in adolescents. Participants included 1804 European adolescents who were recruited in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) Study. Dietary intake was assessed by two, non-consecutive 24 h recalls. A DQI-A score, considering the components dietary quality, diversity and equilibrium, was calculated. Associations between the DQI-A and food and nutrient intakes and blood concentration biomarkers were investigated using multilevel regression analysis corrected for centre, age and sex. DQI-A scores were associated with food intake in the expected direction: positive associations with nutrient-dense food items, such as fruits and vegetables, and inverse associations with energy-dense and low-nutritious foods. On the nutrient level, the DQI-A was positively related to the intake of water, fibre and most minerals and vitamins. No association was found between the DQI-A and total fat intake. Furthermore, a positive association was observed with 25-hydroxyvitamin D, holo-transcobalamin and n-3 fatty acid serum levels. The present study has shown good validity of the DQI-A by confirming the expected associations with food and nutrient intakes and some biomarkers in blood.
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Main characteristics and participation rate of European adolescents included in the HELENA study.
Arch Public Health
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Participation rate and response rate are key issues in a cross sectional large-scale epidemiological study. The objective of this paper is to describe the study population and to evaluate participation and response rate as well as the key nutritional status variables in male and female adolescents involved in the HELENA study.
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Validation of the Vivago Wrist-Worn accelerometer in the assessment of physical activity.
BMC Public Health
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Most accelerometers are worn around the waist (hip or lower back) to assess habitual physical activity. Wrist-worn accelerometers may be an alternative to the waist-worn monitors and may improve compliance in studies with prolonged wear. The aim of this study was to validate the Vivago® Wrist-Worn Accelerometer at various intensities of physical activity (PA) in adults.
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Active relatives and health-related physical fitness in European adolescents: the HELENA Study.
J Sports Sci
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High physical fitness in childhood and adolescence is positively associated with favourable health-related outcomes. Our aim was to examine the relationship between relatives (father, mother, brother, sister, and best friend) physical activity engagement and encouragement on adolescents physical fitness. Adolescents were part of the HELENA study, a multi-centre study conducted in 10 cities from nine European countries in 2006-2008. Participants were 3288 adolescents (48% boys, 52% girls) aged 12.5-17.5 years with valid data on at least one of the three fitness variables studied: muscular strength (standing long jump), speed/agility (4×10 m shuttle run), and cardiorespiratory fitness (20 m shuttle run). The adolescents reported their relatives physical activity engagement and encouragement. Analysis of covariance showed that relatives physical activity engagement (father, mother, brother, and best friend) was positively related to cardiorespiratory fitness (P < 0.05); and mothers and sisters physical activity engagement were positively associated with higher muscular strength in adolescents (P < 0.05). Furthermore, fathers physical activity encouragement was positively linked to physical fitness (all fitness components) in adolescents (P < 0.05). Interventions aimed at improving physical fitness in young people might be more successful when family members, particularly mothers and fathers, are encouraged to engage in physical activity and support adolescents physical activity.
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The six-minute walk test in obese youth: reproducibility, validity, and prediction equation to assess aerobic power.
Disabil Rehabil
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Purpose: The aim of this study was to assess reproducibility and validity of the 6 minute walk test (6MWT) in obese youth and to develop an equation to predict aerobic power (VO(2max)). Methods: Fifty-two girls and 45 boys, ages 7-17.8 participated in the study. Three walk tests were administered 1 week apart. Each visit corresponded to a specific test, either an incremental treadmill test, or the 6MWT. The 6MWT was performed on two occasions 1 week apart to assess reproducibility. Treadmill and walk tests were randomly assigned to avoid order effect. Results: Subjects walked 689.4?±?98.6 m on the initial 6MWT and 690.4?±?98.2 m on the second test. Intraclass correlation coefficient was r = 0.99. The Bland and Altman method also showed good agreement between the two 6MWTs. Stepwise multiple regression determined that distance walked in 6 MWT and BMI are the most significant factors in predicting VO(2max). The prediction equation is VO2 max (ml.kg.min(-1)) = 26.9 + 0.014?×?6 MWT (meters) - 0.38 × BMI (kg/m((2))). Conclusions: In obese youth, the 6 MWT is a reproducible and valid test for assessing aerobic power. A prediction equation was developed to estimate VO(2)max, using distance walked in 6MWT and BMI. [Box: see text].
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Comparative interinstrument reliability of uniaxial and triaxial accelerometers in free-living conditions.
Percept Mot Skills
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The aim of this study was to measure the inter-instrument reliability of the ActiGraph and RT3 accelerometers in free-living conditions. 15 healthy adults wore eight ActiGraph accelerometers and five RT3 accelerometers fastened to their back with an elastic belt and adjustable buckle in free-living conditions. For both accelerometers, the inter-instrument coefficient of variation (CV) decreased with increasing physical activity intensity. The inter-instrument CV of the ActiGraph (3% to 10.5%) was significantly lower than that of the RT3 (12.6% to 35.5%; p < 0.05). This finding demonstrates that the ActiGraph has higher inter-instrument reliability than the RT3. For both accelerometers, the inter-instrument reliability was higher for moderate and vigorous physical activity, the two intensities recommended for public health purposes. Studies using these devices can be compared with a low risk of misclassification of participants who meet the recommendation to perform moderate to vigorous physical activity.
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Can differences in physical activity by socio-economic status in European adolescents be explained by differences in psychosocial correlates? A mediation analysis within the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study.
Public Health Nutr
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Socio-economic status (SES) has been positively associated with physical activity (PA) levels in adolescents. In order to tackle these social inequalities, information is needed about the underlying mechanisms of this association. The present study aimed to investigate the potential mediating role of psychosocial correlates of PA on the relationship between SES and PA in European adolescents.
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A conative educational model for an intervention program in obese youth.
BMC Public Health
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Obesity in children has increased in recent years throughout the world and is associated with adverse health consequences. Early interventions, including appropriate pedagogy strategies, are important for a successful intervention program. The aim of this study was to assess changes in body mass index, the ability to perform sport activities, behavior in the classroom and academic performance following one year of a health-wellness intervention program in obese youth.
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Comparison of two ActiGraph accelerometer generations in the assessment of physical activity in free living conditions.
BMC Res Notes
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The aim of this study was to compare physical activity measured using GT1M ActiGraph and GT3X ActiGraph accelerometers in free living conditions.
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Comparison of uniaxial and triaxial accelerometry in the assessment of physical activity among adolescents under free-living conditions: the HELENA study.
BMC Med Res Methodol
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Different types of devices are available and the choice about which to use depends on various factors: cost, physical characteristics, performance, and the validity and intra- and interinstrument reliability. Given the large number of studies that have used uniaxial or triaxial devices, it is of interest to know whether the different devices give similar information about PA levels and patterns. The aim of this study was to compare physical activity (PA) levels and patterns obtained simultaneously by triaxial accelerometry and uniaxial accelerometry in adolescents in free-living conditions.
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