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Find video protocols related to scientific articles indexed in Pubmed.
Vitamin D Therapy in Individuals with Pre-Hypertension or Hypertension: The DAYLIGHT Trial.
Circulation
PUBLISHED: 11-01-2014
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-A large body of epidemiological and experimental evidence suggests that vitamin D deficiency may promote hypertension. This raises the possibility that vitamin D supplementation could be a simple intervention to reduce blood pressure, but data from prospective, randomized trials are limited.
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Biomarkers of cardiovascular stress and subclinical atherosclerosis in the community.
Clin. Chem.
PUBLISHED: 09-18-2014
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Biomarkers of cardiovascular stress have been associated with incident cardiovascular outcomes. Their relations with measures of subclinical atherosclerosis, as assessed by carotid intima-media thickness, have not been well described.
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The natural history of left ventricular geometry in the community: clinical correlates and prognostic significance of change in LV geometric pattern.
JACC Cardiovasc Imaging
PUBLISHED: 08-13-2014
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This study sought to evaluate pattern and clinical correlates of change in left ventricular (LV) geometry over a 4-year period in the community; it also assessed whether the pattern of change in LV geometry over 4 years predicts incident cardiovascular disease (CVD), including myocardial infarction, heart failure, and cardiovascular death, during an additional subsequent follow-up period.
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Temporal trends in the population attributable risk for cardiovascular disease: the Atherosclerosis Risk in Communities Study.
Circulation
PUBLISHED: 08-11-2014
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The extent to which the relative contributions of traditional cardiovascular risk factors to incident cardiovascular disease (CVD) may have changed over time remains unclear.
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Recognizing and managing left ventricular dysfunction associated with therapeutic inhibition of the vascular endothelial growth factor signaling pathway.
Curr Treat Options Cardiovasc Med
PUBLISHED: 08-08-2014
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Therapeutic inhibition of the vascular endothelial growth factor (VEGF) signaling pathway (VSP) is increasingly employed in the contemporary treatment of many cancer types. VSP inhibitors include the anti-VEGF monoclonal antibody (bevacizumab), soluble VEGF receptors (VEGF Trap), and small molecule tyrosine kinase inhibitors (TKIs) targeting the intracellular kinase domain of VEGF receptors. These agents are associated with cardiovascular toxicities such as hypertension, thrombosis, myocardial ischemia, and left ventricular (LV) dysfunction. Data on VSP inhibitor-associated LV dysfunction are largely limited to retrospective studies. Prospective studies are needed to establish the clinical significance of VSP inhibitor-associated LV dysfunction in the general population. Pre-clinical models of VSP inhibitor-associated LV dysfunction have identified mechanisms of cardiotoxicity and may improve our understanding of the pathophysiology underlying other cardiomyopathies. This review provides an overview of LV dysfunction that can occur in patients treated with VSP inhibitors. Potential strategies for clinical detection and management of this cardiotoxicity are explored, while acknowledging that currently available data specific to VSP-inhibitor LV dysfunction are limited. Avenues for future research are suggested.
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Age and the effectiveness of anti-hypertensive therapy on improvement in diastolic function.
J. Hypertens.
PUBLISHED: 08-02-2014
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Diastolic dysfunction is associated with adverse outcomes and is highly prevalent among older adults with hypertension. Lowering SBP with antihypertensive therapy has been shown to improve diastolic function, but whether or not age influences this effect is unknown.
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Stromal cell-derived factor 1 as a biomarker of heart failure and mortality risk.
Arterioscler. Thromb. Vasc. Biol.
PUBLISHED: 07-24-2014
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CXCL12 encodes stromal cell-derived factor 1? (SDF-1), which binds to the receptor encoded by CXCR4. Variation at the CXCL12 locus is associated with coronary artery disease and endothelial progenitor cell numbers, whereas variation at the CXCR4 locus is associated with leukocyte telomere length, which has been shown to be associated with coronary artery disease. Therefore, we examined the relationships of plasma SDF-1 levels to cardiovascular disease (CVD)-related outcomes, risk factors, leukocyte telomere length, and endothelial progenitor cells.
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Metabolite traits and genetic risk provide complementary information for the prediction of future type 2 diabetes.
Diabetes Care
PUBLISHED: 06-19-2014
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A genetic risk score (GRS) comprised of single nucleotide polymorphisms (SNPs) and metabolite biomarkers have each been shown, separately, to predict incident type 2 diabetes. We tested whether genetic and metabolite markers provide complementary information for type 2 diabetes prediction and, together, improve the accuracy of prediction models containing clinical traits.
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Associations Between Echocardiographic Arterial Compliance and Incident Cardiovascular Disease in Blacks: The ARIC Study.
Am. J. Hypertens.
PUBLISHED: 05-21-2014
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Systemic arterial compliance is sometimes derived by echocardiographic stroke volume to pulse pressure ratios. Few studies have assessed echocardiographic arterial compliance in blacks or its associations with explicit, rather than composite, cardiovascular disease (CVD) outcomes.
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Long-term cardiovascular risks associated with an elevated heart rate: the Framingham Heart Study.
J Am Heart Assoc
PUBLISHED: 05-10-2014
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Higher heart rate has been associated with an adverse prognosis, but most prior studies focused on individuals with known cardiovascular disease or examined a limited number of outcomes. We sought to examine the association of baseline heart rate with both fatal and nonfatal outcomes during 2 decades of follow-up.
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Cardiac target organ damage in hypertension: insights from epidemiology.
Curr. Hypertens. Rep.
PUBLISHED: 05-08-2014
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Hypertension is an important risk factor implicated in the development of multiple common cardiac conditions, including coronary atherosclerosis, heart failure, and atrial fibrillation. Epidemiologic studies have provided insights into the shared pathogenesis of hypertension and subclinical as well as clinically evident cardiac diseases. The mechanistic common ground between chronic blood pressure elevation and cardiac disease likely begins early in life. Understanding these connections will aid ongoing efforts to identify individuals at risk, develop targeted therapeutics, and improve overall outcomes for individuals with elevated blood pressure in the population at large.
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Delays and errors in abnormal chest radiograph follow-up: a systems approach to promoting patient safety in radiology.
J Eval Clin Pract
PUBLISHED: 04-17-2014
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This study aimed to apply the 'systems approach' to patient safety in order to identify causes for delays and errors in lung cancer diagnoses following an abnormal chest radiograph.
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Genetic loci associated with atrial fibrillation: relation to left atrial structure in the Framingham Heart Study.
J Am Heart Assoc
PUBLISHED: 04-04-2014
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Atrial fibrillation (AF) results in significant morbidity and mortality. Genome-wide association studies (GWAS) have identified genetic variants associated with AF. Whether genetic variants associated with AF are also associated with atrial structure, an intermediate phenotype for AF, has had limited investigation. We sought to investigate associations between single nucleotide polymorphisms (SNPs) and atrial structure obtained by cardiovascular imaging in the Framingham Heart Study.
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Association of exhaled carbon monoxide with subclinical cardiovascular disease and their conjoint impact on the incidence of cardiovascular outcomes.
Eur. Heart J.
PUBLISHED: 02-25-2014
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Whereas endogenous carbon monoxide (CO) is cytoprotective at physiologic levels, excess CO concentrations are associated with cardiometabolic risk and may represent an important marker of progression from subclinical to clinical cardiovascular disease (CVD).
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Assessment of right ventricular structure and function in mouse model of pulmonary artery constriction by transthoracic echocardiography.
J Vis Exp
PUBLISHED: 02-12-2014
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Emerging clinical data support the notion that RV dysfunction is critical to the pathogenesis of cardiovascular disease and heart failure(1-3). Moreover, the RV is significantly affected in pulmonary diseases such as pulmonary artery hypertension (PAH). In addition, the RV is remarkably sensitive to cardiac pathologies, including left ventricular (LV) dysfunction, valvular disease or RV infarction(4). To understand the role of RV in the pathogenesis of cardiac diseases, a reliable and noninvasive method to access the RV structurally and functionally is essential. A noninvasive trans-thoracic echocardiography (TTE) based methodology was established and validated for monitoring dynamic changes in RV structure and function in adult mice. To impose RV stress, we employed a surgical model of pulmonary artery constriction (PAC) and measured the RV response over a 7-day period using a high-frequency ultrasound microimaging system. Sham operated mice were used as controls. Images were acquired in lightly anesthetized mice at baseline (before surgery), day 0 (immediately post-surgery), day 3, and day 7 (post-surgery). Data was analyzed offline using software. Several acoustic windows (B, M, and Color Doppler modes), which can be consistently obtained in mice, allowed for reliable and reproducible measurement of RV structure (including RV wall thickness, end-diastolic and end-systolic dimensions), and function (fractional area change, fractional shortening, PA peak velocity, and peak pressure gradient) in normal mice and following PAC. Using this method, the pressure-gradient resulting from PAC was accurately measured in real-time using Color Doppler mode and was comparable to direct pressure measurements performed with a Millar high-fidelity microtip catheter. Taken together, these data demonstrate that RV measurements obtained from various complimentary views using echocardiography are reliable, reproducible and can provide insights regarding RV structure and function. This method will enable a better understanding of the role of RV cardiac dysfunction.
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Ultrasonic assessment of myocardial microstructure.
J Vis Exp
PUBLISHED: 01-25-2014
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Echocardiography is a widely accessible imaging modality that is commonly used to noninvasively characterize and quantify changes in cardiac structure and function. Ultrasonic assessments of cardiac tissue can include analyses of backscatter signal intensity within a given region of interest. Previously established techniques have relied predominantly on the integrated or mean value of backscatter signal intensities, which may be susceptible to variability from aliased data from low frame rates and time delays for algorithms based on cyclic variation. Herein, we describe an ultrasound-based imaging algorithm that extends from previous methods, can be applied to a single image frame and accounts for the full distribution of signal intensity values derived from a given myocardial sample. When applied to representative mouse and human imaging data, the algorithm distinguishes between subjects with and without exposure to chronic afterload resistance. The algorithm offers an enhanced surrogate measure of myocardial microstructure and can be performed using open-access image analysis software.
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Sex-specific cardiovascular structure and function in heart failure with preserved ejection fraction.
Eur. J. Heart Fail.
PUBLISHED: 01-12-2014
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Women are more likely to develop heart failure with preserved ejection fraction (HFpEF) than men. We studied the relationship between sex and cardiovascular structure and function in patients with HFpEF.
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Identifying early changes in myocardial microstructure in hypertensive heart disease.
PLoS ONE
PUBLISHED: 01-01-2014
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The transition from healthy myocardium to hypertensive heart disease is characterized by a series of poorly understood changes in myocardial tissue microstructure. Incremental alterations in the orientation and integrity of myocardial fibers can be assessed using advanced ultrasonic image analysis. We used a modified algorithm to investigate left ventricular myocardial microstructure based on analysis of the reflection intensity at the myocardial-pericardial interface on B-mode echocardiographic images. We evaluated the extent to which the novel algorithm can differentiate between normal myocardium and hypertensive heart disease in humans as well as in a mouse model of afterload resistance. The algorithm significantly differentiated between individuals with uncomplicated essential hypertension (N?=?30) and healthy controls (N?=?28), even after adjusting for age and sex (P?=?0.025). There was a trend in higher relative wall thickness in hypertensive individuals compared to controls (P?=?0.08), but no difference between groups in left ventricular mass (P?=?0.98) or total wall thickness (P?=?0.37). In mice, algorithm measurements (P?=?0.026) compared with left ventricular mass (P?=?0.053) more clearly differentiated between animal groups that underwent fixed aortic banding, temporary aortic banding, or sham procedure, on echocardiography at 7 weeks after surgery. Based on sonographic signal intensity analysis, a novel imaging algorithm provides an accessible, non-invasive measure that appears to differentiate normal left ventricular microstructure from myocardium exposed to chronic afterload stress. The algorithm may represent a particularly sensitive measure of the myocardial changes that occur early in the course of disease progression.
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Association of novel biomarkers of cardiovascular stress with left ventricular hypertrophy and dysfunction: implications for screening.
J Am Heart Assoc
PUBLISHED: 11-09-2013
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Currently available screening tools for left ventricular (LV) hypertrophy (LVH) and systolic dysfunction (LVSD) are either expensive (echocardiography) or perform suboptimally (B-type natriuretic peptide [BNP]). It is unknown whether newer biomarkers are associated with LVH and LVSD and can serve as screening tools.
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Rationale and Design of a Multicenter Echocardiographic Study to Assess the Relationship Between Cardiac Structure and Function and Heart Failure Risk in a Biracial Cohort of Community Dwelling Elderly Persons: The Atherosclerosis Risk in Communities (ARI
Circ Cardiovasc Imaging
PUBLISHED: 11-08-2013
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-Heart failure (HF) is an important public health concern particularly among persons over 65 years of age. Women and African Americans are critically understudied populations that carry a sizeable portion of the HF burden. Limited normative and prognostic data exist regarding measures of cardiac structure, diastolic function, and novel measures of systolic deformation in older adults living in the community.
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Secular trends in echocardiographic left ventricular mass in the community: the Framingham Heart Study.
Heart
PUBLISHED: 09-16-2013
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To investigate secular trends in echocardiographically determined left ventricular mass (LVM).
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Aortic Root Remodeling and Risk of Heart Failure in the Framingham Heart Study.
JACC Heart Fail
PUBLISHED: 09-03-2013
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The aim of this study was to investigate the association between aortic root remodeling and incident heart failure (HF).
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Reproducibility of speckle-tracking-based strain measures of left ventricular function in a community-based study.
J Am Soc Echocardiogr
PUBLISHED: 08-14-2013
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The reproducibility of echocardiographic measurements of myocardial strain, performed in a community-based setting, has not been reported previously.
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Influence of age-related versus non-age-related renal dysfunction on survival in patients with left ventricular dysfunction.
Am. J. Cardiol.
PUBLISHED: 08-08-2013
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Normal aging results in a predictable decrease in glomerular filtration rate (GFR), and low GFR is associated with worsened survival. If this survival disadvantage is directly caused by the low GFR, as opposed to the disease causing the low GFR, the risk should be similar regardless of the underlying mechanism. Our objective was to determine if age-related decreases in estimated GFR (eGFR) carry the same prognostic importance as disease-attributable losses in patients with ventricular dysfunction. We analyzed the Studies Of Left Ventricular Dysfunction limited data set (n = 6,337). The primary analysis focused on determining if the eGFR-mortality relation differed by the extent to which the eGFR was consistent with normal aging. Mean eGFR was 65.7 ml/min/1.73 m(2) (SD = 19.0). Across the range of age in the population (27 to 80 years), baseline eGFR decreased by 0.67 ml/min/1.73 m(2)/year (95% confidence interval [CI] 0.63 to 0.71). The risk of death associated with eGFR was strongly modified by the degree to which the low eGFR could be explained by aging (p for interaction <0.0001). For example, in a model incorporating the interaction, uncorrected eGFR was no longer significantly related to mortality (adjusted hazard ratio 1.0 per 10 ml/min/1.73 m(2), 95% CI 0.97 to 1.1, p = 0.53), whereas a disease-attributable decrease in eGFR above the median carried significant risk (adjusted hazard ratio 2.8, 95% CI 1.6 to 4.7, p <0.001). In conclusion, in the setting of left ventricular dysfunction, renal dysfunction attributable to normal aging had a limited risk for mortality, suggesting that the mechanism underlying renal dysfunction is critical in determining prognosis.
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Age- and sex-based reference limits and clinical correlates of myocardial strain and synchrony: the Framingham Heart Study.
Circ Cardiovasc Imaging
PUBLISHED: 08-05-2013
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There is rapidly growing interest in applying measures of myocardial strain and synchrony in clinical investigations and in practice; data are limited regarding their reference ranges in healthy individuals.
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Differential influence of distinct components of increased blood pressure on cardiovascular outcomes: from the atherosclerosis risk in communities study.
Hypertension
PUBLISHED: 07-22-2013
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Elevation in blood pressure (BP) increases risk for all cardiovascular events. Nevertheless, the extent to which different indices of BP elevation may be associated to varying degrees with different cardiovascular outcomes remains unclear. We studied 13340 participants (aged 54 ± 6 years, 56% women and 27% black) of the Atherosclerosis Risk in Communities Study who were free of baseline cardiovascular disease. We used Cox proportional hazards models to compare the relative contributions of systolic BP, diastolic BP, pulse pressure, and mean arterial pressure to risk for coronary heart disease, heart failure, stroke, and all-cause mortality. For each multivariable-adjusted model, the largest area under the receiver-operating curve (AUC) and smallest -2 log-likelihood values were used to identify BP measures with the greatest contribution to risk prediction for each outcome. A total of 2095 coronary heart disease events, 1669 heart failure events, 771 stroke events, and 3016 deaths occurred during 18 ± 5 years of follow-up. In multivariable analyses adjusting for traditional cardiovascular risk factors, the BP measures with the greatest risk contributions were the following: systolic BP for coronary heart disease (AUC=0.74); pulse pressure for heart failure (AUC=0.79); systolic BP for stroke (AUC=0.74); and pulse pressure for all-cause mortality (AUC=0.74). With few exceptions, results were similar in analyses stratified by age, sex, and race. Our data indicate that distinct BP components contribute variably to risk for different cardiovascular outcomes.
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Biomarkers of cardiovascular stress and incident chronic kidney disease.
Clin. Chem.
PUBLISHED: 07-19-2013
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Growth differentiation factor-15 (GDF-15), soluble ST2 (sST2), and high-sensitivity troponin I (hsTnI) are emerging predictors of adverse clinical outcomes. We examined whether circulating concentrations are related to the development of kidney disease in the community.
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Common genetic variation at the IL1RL1 locus regulates IL-33/ST2 signaling.
J. Clin. Invest.
PUBLISHED: 06-27-2013
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The suppression of tumorigenicity 2/IL-33 (ST2/IL-33) pathway has been implicated in several immune and inflammatory diseases. ST2 is produced as 2 isoforms. The membrane-bound isoform (ST2L) induces an immune response when bound to its ligand, IL-33. The other isoform is a soluble protein (sST2) that is thought to be a decoy receptor for IL-33 signaling. Elevated sST2 levels in serum are associated with an increased risk for cardiovascular disease. We investigated the determinants of sST2 plasma concentrations in 2,991 Framingham Offspring Cohort participants. While clinical and environmental factors explained some variation in sST2 levels, much of the variation in sST2 production was driven by genetic factors. In a genome-wide association study (GWAS), multiple SNPs within IL1RL1 (the gene encoding ST2) demonstrated associations with sST2 concentrations. Five missense variants of IL1RL1 correlated with higher sST2 levels in the GWAS and mapped to the intracellular domain of ST2, which is absent in sST2. In a cell culture model, IL1RL1 missense variants increased sST2 expression by inducing IL-33 expression and enhancing IL-33 responsiveness (via ST2L). Our data suggest that genetic variation in IL1RL1 can result in increased levels of sST2 and alter immune and inflammatory signaling through the ST2/IL-33 pathway.
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Relation of N-terminal pro-B-type natriuretic peptide with diastolic function in hypertensive heart disease.
Am. J. Hypertens.
PUBLISHED: 06-22-2013
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Elevated natriuretic peptide levels in asymptomatic individuals without heart failure are associated with increased risk of adverse cardiovascular outcomes and may reflect subclinical cardiac dysfunction.
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A combined epidemiologic and metabolomic approach improves CKD prediction.
J. Am. Soc. Nephrol.
PUBLISHED: 05-16-2013
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Metabolomic approaches have begun to catalog the metabolic disturbances that accompany CKD, but whether metabolite alterations can predict future CKD is unknown. We performed liquid chromatography/mass spectrometry-based metabolite profiling on plasma from 1434 participants in the Framingham Heart Study (FHS) who did not have CKD at baseline. During the following 8 years, 123 individuals developed CKD, defined by an estimated GFR of <60 ml/min per 1.73 m(2). Numerous metabolites were associated with incident CKD, including 16 that achieved the Bonferroni-adjusted significance threshold of P?0.00023. To explore how the human kidney modulates these metabolites, we profiled arterial and renal venous plasma from nine individuals. Nine metabolites that predicted CKD in the FHS cohort decreased more than creatinine across the renal circulation, suggesting that they may reflect non-GFR-dependent functions, such as renal metabolism and secretion. Urine isotope dilution studies identified citrulline and choline as markers of renal metabolism and kynurenic acid as a marker of renal secretion. In turn, these analytes remained associated with incident CKD in the FHS cohort, even after adjustment for eGFR, age, sex, diabetes, hypertension, and proteinuria at baseline. Addition of a multimarker metabolite panel to clinical variables significantly increased the c-statistic (0.77-0.83, P<0.0001); net reclassification improvement was 0.78 (95% confidence interval, 0.60 to 0.95; P<0.0001). Thus, the addition of metabolite profiling to clinical data may significantly improve the ability to predict whether an individual will develop CKD by identifying predictors of renal risk that are independent of estimated GFR.
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Cardiovascular complications of radiation therapy for thoracic malignancies: the role for non-invasive imaging for detection of cardiovascular disease.
Eur. Heart J.
PUBLISHED: 05-10-2013
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Radiation exposure to the thorax is associated with substantial risk for the subsequent development of cardiovascular disease. Thus, the increasing role of radiation therapy in the contemporary treatment of cancer, combined with improving survival rates of patients undergoing this therapy, contributes to a growing population at risk of cardiovascular morbidity and mortality. Associated cardiovascular injuries include pericardial disease, coronary artery disease, valvular disease, conduction disease, cardiomyopathy, and medium and large vessel vasculopathy-any of which can occur at varying intervals following irradiation. Higher radiation doses, younger age at the time of irradiation, longer intervals from the time of radiation, and coexisting cardiovascular risk factors all predispose to these injuries. The true incidence of radiation-related cardiovascular disease remains uncertain due to lack of large multicentre studies with a sufficient duration of cardiovascular follow-up. There are currently no consensus guidelines available to inform the optimal approach to cardiovascular surveillance of recipients of thoracic radiation. Therefore, we review the cardiovascular consequences of radiation therapy and focus on the potential role of non-invasive cardiovascular imaging in the assessment and management of radiation-related cardiovascular disease. In doing so, we highlight characteristics that can be used to identify individuals at risk for developing post-radiation cardiovascular disease and propose an imaging-based algorithm for their clinical surveillance.
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Soluble ST2 predicts elevated SBP in the community.
J. Hypertens.
PUBLISHED: 04-26-2013
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Soluble ST2 (sST2) is an emerging prognostic biomarker in patients with existing cardiovascular disease. ST2 and its ligand, interleukin-33 (IL-33), are expressed in endothelial cells, and may play an important role in the development of early atherosclerosis and vascular biology. We sought to investigate the association of sST2 and progression of blood pressure (BP), as well as the development of hypertension.
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Circulating CD31+ leukocyte frequency is associated with cardiovascular risk factors.
Atherosclerosis
PUBLISHED: 03-01-2013
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CD31 identifies a heterogeneous population of cells in the blood, consisting of mature leukocytes and platelets, as well as smaller numbers of endothelial and progenitor cells. Because unfractionated CD31+ blood cells have demonstrated angiogenic properties in vivo, we hypothesized that circulating CD31+ cells would be related to the presence of cardiovascular risk factors in humans.
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Metabolite profiles during oral glucose challenge.
Diabetes
PUBLISHED: 02-04-2013
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To identify distinct biological pathways of glucose metabolism, we conducted a systematic evaluation of biochemical changes after an oral glucose tolerance test (OGTT) in a community-based population. Metabolic profiling was performed on 377 nondiabetic Framingham Offspring cohort participants (mean age 57 years, 42% women, BMI 30 kg/m(2)) before and after OGTT. Changes in metabolite levels were evaluated with paired Student t tests, cluster-based analyses, and multivariable linear regression to examine differences associated with insulin resistance. Of 110 metabolites tested, 91 significantly changed with OGTT (P ? 0.0005 for all). Amino acids, ?-hydroxybutyrate, and tricarboxylic acid cycle intermediates decreased after OGTT, and glycolysis products increased, consistent with physiological insulin actions. Other pathways affected by OGTT included decreases in serotonin derivatives, urea cycle metabolites, and B vitamins. We also observed an increase in conjugated, and a decrease in unconjugated, bile acids. Changes in ?-hydroxybutyrate, isoleucine, lactate, and pyridoxate were blunted in those with insulin resistance. Our findings demonstrate changes in 91 metabolites representing distinct biological pathways that are perturbed in response to an OGTT. We also identify metabolite responses that distinguish individuals with and without insulin resistance. These findings suggest that unique metabolic phenotypes can be unmasked by OGTT in the prediabetic state.
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Regional cardiac dysfunction and dyssynchrony in a murine model of afterload stress.
PLoS ONE
PUBLISHED: 01-31-2013
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Small animal models of afterload stress have contributed much to our present understanding of the progression from hypertension to heart failure. High-sensitivity methods for phenotyping cardiac function in vivo, particular in the setting of compensated cardiac hypertrophy, may add new information regarding alterations in cardiac performance that can occur even during the earliest stages of exposure to pressure overload. We have developed an echocardiographic analytical method, based on speckle-tracking-based strain analyses, and used this tool to rapidly phenotype cardiac changes resulting from afterload stress in a small animal model. Adult mice were subjected to ascending aortic constriction, with and without subsequent reversal of the pressure gradient. In this model of compensated hypertrophic cardiac remodeling, conventional echocardiographic measurements did not detect changes in left ventricular (LV) function at the early time points examined. Strain analyses, however, revealed a decrement in basal longitudinal myofiber shortening that was induced by aortic constriction and improved following relief of the pressure gradient. Furthermore, we observed that pressure overload resulted in LV segmental dyssynchrony that was attenuated with return of the afterload to baseline levels. Herein, we describe the use of echocardiographic strain analyses for cardiac phenotyping in a mouse model of pressure overload. This method provides evidence of dyssynchrony and regional myocardial dysfunction that occurs early with compensatory hypertrophy, and improves following relief of aortic constriction. Importantly, these findings illustrate the utility of a rapid, non-invasive method for characterizing early cardiac dysfunction, not detectable by conventional echocardiography, following afterload stress.
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2-Aminoadipic acid is a biomarker for diabetes risk.
J. Clin. Invest.
PUBLISHED: 01-11-2013
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Improvements in metabolite-profiling techniques are providing increased breadth of coverage of the human metabolome and may highlight biomarkers and pathways in common diseases such as diabetes. Using a metabolomics platform that analyzes intermediary organic acids, purines, pyrimidines, and other compounds, we performed a nested case-control study of 188 individuals who developed diabetes and 188 propensity-matched controls from 2,422 normoglycemic participants followed for 12 years in the Framingham Heart Study. The metabolite 2-aminoadipic acid (2-AAA) was most strongly associated with the risk of developing diabetes. Individuals with 2-AAA concentrations in the top quartile had greater than a 4-fold risk of developing diabetes. Levels of 2-AAA were not well correlated with other metabolite biomarkers of diabetes, such as branched chain amino acids and aromatic amino acids, suggesting they report on a distinct pathophysiological pathway. In experimental studies, administration of 2-AAA lowered fasting plasma glucose levels in mice fed both standard chow and high-fat diets. Further, 2-AAA treatment enhanced insulin secretion from a pancreatic ? cell line as well as murine and human islets. These data highlight a metabolite not previously associated with diabetes risk that is increased up to 12 years before the onset of overt disease. Our findings suggest that 2-AAA is a marker of diabetes risk and a potential modulator of glucose homeostasis in humans.
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A genome-wide association study of the human metabolome in a community-based cohort.
Cell Metab.
PUBLISHED: 01-11-2013
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Because metabolites are hypothesized to play key roles as markers and effectors of cardiometabolic diseases, recent studies have sought to annotate the genetic determinants of circulating metabolite levels. We report a genome-wide association study (GWAS) of 217 plasma metabolites, including >100 not measured in prior GWAS, in 2076 participants of the Framingham Heart Study (FHS). For the majority of analytes, we find that estimated heritability explains >20% of interindividual variation, and that variation attributable to heritable factors is greater than that attributable to clinical factors. Further, we identify 31 genetic loci associated with plasma metabolites, including 23 that have not previously been reported. Importantly, we include GWAS results for all surveyed metabolites and demonstrate how this information highlights a role for AGXT2 in cholesterol ester and triacylglycerol metabolism. Thus, our study outlines the relative contributions of inherited and clinical factors on the plasma metabolome and provides a resource for metabolism research.
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Circulating CD34(+) progenitor cell frequency is associated with clinical and genetic factors.
Blood
PUBLISHED: 01-03-2013
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Circulating blood CD34(+) cells consist of hematopoietic stem/progenitor cells, angiogenic cells, and endothelial cells. In addition to their clinical use in hematopoietic stem cell transplantation, CD34(+) cells may also promote therapeutic neovascularization. Therefore, understanding the factors that influence circulating CD34(+) cell frequency has wide implications for vascular biology in addition to stem cell transplantation. In the present study, we examined the clinical and genetic characteristics associated with circulating CD34(+) cell frequency in a large, community-based sample of 1786 Framingham Heart Study participants.Among subjects without cardiovascular disease (n = 1595), CD34(+) frequency was inversely related to older age, female sex, and smoking. CD34(+) frequency was positively related to weight, serum total cholesterol, and statin therapy. Clinical covariates accounted for 6.3% of CD34(+) variability. CD34(+) frequency was highly heritable (h(2) = 54%; P < .0001). Genome-wide association analysis of CD34(+) frequency identified suggestive associations at several loci, including OR4C12 (chromosome 11; P = 6.7 × 10(-7)) and ENO1 and RERE (chromosome 1; P = 8.8 × 10(-7)). CD34(+) cell frequency is reduced in older subjects and is influenced by environmental factors including smoking and statin use. CD34(+) frequency is highly heritable. The results of the present study have implications for therapies that use CD34(+) cell populations and support efforts to better understand the genetic mechanisms that underlie CD34(+) frequency.
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Cardiac natriuretic peptides, obesity, and insulin resistance: evidence from two community-based studies.
J. Clin. Endocrinol. Metab.
PUBLISHED: 08-17-2011
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The natriuretic peptides play an important role in salt homeostasis and blood pressure regulation. It has been suggested that obesity promotes a relative natriuretic peptide deficiency, but this has been a variable finding in prior studies and the cause is unknown.
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The relationship between renal impairment and left ventricular structure, function, and ventricular-arterial interaction in hypertension.
J. Hypertens.
PUBLISHED: 07-30-2011
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Our objective was to define the relationship between renal dysfunction--both albuminuria and reduced estimated glomerular filtration rate (eGFR)--and cardiac structure and diastolic dysfunction among patients with chronic hypertension.
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Circulating angiogenic cell populations, vascular function, and arterial stiffness.
Atherosclerosis
PUBLISHED: 07-12-2011
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Several bone marrow-derived cell populations have been identified that may possess angiogenic activity and contribute to vascular homeostasis in experimental studies. We examined the extent to which lower quantities of these circulating angiogenic cell phenotypes may be related to impaired vascular function and greater arterial stiffness.
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Dyssynchrony, contractile function, and response to cardiac resynchronization therapy.
Circ Heart Fail
PUBLISHED: 05-22-2011
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Despite benefits of cardiac resynchronization therapy (CRT) in patients with severe but less symptomatic heart failure, approximately 30% of patients do not fully respond to treatment. We hypothesized that a combined assessment of left ventricular (LV) dyssynchrony and contractile function by strain-based imaging would identify patients who would most benefit from CRT.
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Genetic and clinical correlates of early-outgrowth colony-forming units.
Circ Cardiovasc Genet
PUBLISHED: 04-14-2011
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Several bone marrow-derived cell populations may have angiogenic activity, including cells termed endothelial progenitor cells. Decreased numbers of circulating angiogenic cell populations have been associated with increased cardiovascular risk. However, few data exist from large, unselected samples, and the genetic determinants of these traits are unclear.
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Reference limits for N-terminal-pro-B-type natriuretic peptide in healthy individuals (from the Framingham Heart Study).
Am. J. Cardiol.
PUBLISHED: 04-05-2011
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N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) is a commonly measured cardiovascular biomarker in ambulatory and hospital settings. Nonetheless, there are limited data regarding "normal" ranges for NT-pro-BNP in healthy subjects, despite the importance of such information for interpreting natriuretic peptide measurements. In this study, a healthy reference sample free of cardiovascular disease from the Framingham Heart Study Generation 3 cohort was examined; there were 2,285 subjects (mean age 38 years, 56% women). Plasma NT-pro-BNP levels were measured using the Roche Diagnostics Elecsys 2010 assay, and reference values (2.5th, 50th, and 97.5th quantiles) were determined using empiric and quantile regression methods. Gender, age, blood pressure, and body mass index accounted for approximately 33% of the interindividual variability in NT-pro-BNP in the reference sample. NT-pro-BNP values were substantially higher in women compared to men at every age, and levels increased with increasing age for both genders. Using quantile regression, the upper reference values (97.5th quantile) for NT-pro-BNP were 42.5 to 106.4 pg/ml in men (depending on age) and 111.0 to 215.9 pg/ml in women. Intraindividual variability was assessed in an additional 12 healthy subjects, who had serial NT-pro-BNP measurements over 1 month. Intraclass correlation was 0.85, indicating that most of the variability in NT-pro-BNP concentrations was among rather than within subjects. However, the reference change value was 100%, suggesting that small proportional differences in NT-pro-BNP could be attributable to analytic variability. In conclusion, the reference limits obtained from this large, healthy, community-based sample may aid in the evaluation of NT-pro-BNP concentrations measured for clinical and research purposes.
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Vitamin D status is not related to development of atrial fibrillation in the community.
Am. Heart J.
PUBLISHED: 03-24-2011
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Atrial fibrillation (AF) is common and is an important cause of cardiovascular morbidity and mortality. Vitamin D is an emerging risk factor in cardiovascular disease, and vitamin D status is modifiable. Thus, we sought to investigate whether vitamin D status predisposed to the development of AF in a community-based sample.
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Relation of visceral adiposity to circulating natriuretic peptides in ambulatory individuals.
Am. J. Cardiol.
PUBLISHED: 03-23-2011
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Natriuretic peptides have important roles in the regulation of vasomotor tone, salt homeostasis, and ventricular remodeling. Lower natriuretic peptide levels observed in obese individuals may underlie the greater cardiovascular risk associated with obesity. Thus the aim of this study was to determine whether lower natriuretic peptide levels in obesity are attributable to differences in regional fat distribution. We investigated the relation of plasma N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) to regional adiposity in 1,873 community-based individuals (46% women, mean age 45 years). Subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) volumes were measured by multidetector computed tomography. In gender-specific multivariable analyses adjusting for age and blood pressure, log NT-pro-BNP was inversely associated with VAT in men (beta -0.11 per standard deviation increment, p <0.001) and women (beta -0.19, p <0.001). Log NT-pro-BNP was inversely associated with SAT in women only (beta -0.14, p <0.001). In models containing VAT and SAT, only VAT was significantly associated with log NT-pro-BNP (men, beta -0.137, p <0.001; women, beta -0.184, p <0.001). VAT remained associated with log NT-pro-BNP even after adjustment for body mass index and waist circumference (beta -0.119, p <0.001) and in analyses restricted to nonobese patients (beta -0.165, p <0.001). Adjustment for insulin resistance attenuated the associations of NT-pro-BNP with VAT and SAT. In conclusion, this study demonstrates that circulating NT-pro-BNP is related to variations in regional and particularly visceral adiposity. These findings suggest that excess visceral adiposity and concomitant hyperinsulinemia may contribute to the natriuretic peptide "deficiency" observed in obesity.
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Influence of sex and hormone status on circulating natriuretic peptides.
J. Am. Coll. Cardiol.
PUBLISHED: 03-15-2011
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The aim of this study was to assess the relationship between sex hormones and natriuretic peptide levels in community-based adults.
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Echocardiographic speckle-tracking based strain imaging for rapid cardiovascular phenotyping in mice.
Circ. Res.
PUBLISHED: 03-03-2011
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High-sensitivity in vivo phenotyping of cardiac function is essential for evaluating genes of interest and novel therapies in small animal models of cardiovascular disease. Transthoracic echocardiography is the principal method currently used for assessing cardiac structure and function; however, standard echocardiographic techniques are relatively insensitive to early or subtle changes in cardiac performance, particularly in mice.
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Racial and ethnic differences in subclinical myocardial function: the Multi-Ethnic Study of Atherosclerosis.
Heart
PUBLISHED: 01-21-2011
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Racial/ethnic differences in the incidence and severity of heart failure (HF) are not well understood, but may be related to pre-existing variations in myocardial function.
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Metabolite profiles and the risk of developing diabetes.
Nat. Med.
PUBLISHED: 01-19-2011
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Emerging technologies allow the high-throughput profiling of metabolic status from a blood specimen (metabolomics). We investigated whether metabolite profiles could predict the development of diabetes. Among 2,422 normoglycemic individuals followed for 12 years, 201 developed diabetes. Amino acids, amines and other polar metabolites were profiled in baseline specimens by liquid chromatography-tandem mass spectrometry (LC-MS). Cases and controls were matched for age, body mass index and fasting glucose. Five branched-chain and aromatic amino acids had highly significant associations with future diabetes: isoleucine, leucine, valine, tyrosine and phenylalanine. A combination of three amino acids predicted future diabetes (with a more than fivefold higher risk for individuals in top quartile). The results were replicated in an independent, prospective cohort. These findings underscore the potential key role of amino acid metabolism early in the pathogenesis of diabetes and suggest that amino acid profiles could aid in diabetes risk assessment.
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Lipid profiling identifies a triacylglycerol signature of insulin resistance and improves diabetes prediction in humans.
J. Clin. Invest.
PUBLISHED: 01-19-2011
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Dyslipidemia is an independent risk factor for type 2 diabetes, although exactly which of the many plasma lipids contribute to this remains unclear. We therefore investigated whether lipid profiling can inform diabetes prediction by performing liquid chromatography/mass spectrometry-based lipid profiling in 189 individuals who developed type 2 diabetes and 189 matched disease-free individuals, with over 12 years of follow up in the Framingham Heart Study. We found that lipids of lower carbon number and double bond content were associated with an increased risk of diabetes, whereas lipids of higher carbon number and double bond content were associated with decreased risk. This pattern was strongest for triacylglycerols (TAGs) and persisted after multivariable adjustment for age, sex, BMI, fasting glucose, fasting insulin, total triglycerides, and HDL cholesterol. A combination of 2 TAGs further improved diabetes prediction. To explore potential mechanisms that modulate the distribution of plasma lipids, we performed lipid profiling during oral glucose tolerance testing, pharmacologic interventions, and acute exercise testing. Levels of TAGs associated with increased risk for diabetes decreased in response to insulin action and were elevated in the setting of insulin resistance. Conversely, levels of TAGs associated with decreased diabetes risk rose in response to insulin and were poorly correlated with insulin resistance. These studies identify a relationship between lipid acyl chain content and diabetes risk and demonstrate how lipid profiling could aid in clinical risk assessment.
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Exhaled carbon monoxide and risk of metabolic syndrome and cardiovascular disease in the community.
Circulation
PUBLISHED: 09-27-2010
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Endogenous carbon monoxide (CO) at physiological concentrations is cytoprotective, whereas excess levels reflect underlying oxidative stress, inflammation, and vascular pathology and portend adverse clinical sequelae. However, the relation of exhaled CO to metabolic/vascular risk in the community is unknown.
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Association of colony-forming units with coronary artery and abdominal aortic calcification.
Circulation
PUBLISHED: 09-07-2010
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Certain bone marrow-derived cell populations, called endothelial progenitor cells, have been reported to possess angiogenic activity. Experimental data suggest that depletion of these angiogenic cell populations may promote atherogenesis, but limited data are available on their relation to subclinical atherosclerotic cardiovascular disease in humans.
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Correlates of echocardiographic indices of cardiac remodeling over the adult life course: longitudinal observations from the Framingham Heart Study.
Circulation
PUBLISHED: 07-26-2010
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The heart progressively remodels over the life course, yet longitudinal data characterizing such remodeling in the community are limited.
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Metabolic signatures of exercise in human plasma.
Sci Transl Med
PUBLISHED: 05-28-2010
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Exercise provides numerous salutary effects, but our understanding of how these occur is limited. To gain a clearer picture of exercise-induced metabolic responses, we have developed comprehensive plasma metabolite signatures by using mass spectrometry to measure >200 metabolites before and after exercise. We identified plasma indicators of glycogenolysis (glucose-6-phosphate), tricarboxylic acid cycle span 2 expansion (succinate, malate, and fumarate), and lipolysis (glycerol), as well as modulators of insulin sensitivity (niacinamide) and fatty acid oxidation (pantothenic acid). Metabolites that were highly correlated with fitness parameters were found in subjects undergoing acute exercise testing and marathon running and in 302 subjects from a longitudinal cohort study. Exercise-induced increases in glycerol were strongly related to fitness levels in normal individuals and were attenuated in subjects with myocardial ischemia. A combination of metabolites that increased in plasma in response to exercise (glycerol, niacinamide, glucose-6-phosphate, pantothenate, and succinate) up-regulated the expression of nur77, a transcriptional regulator of glucose utilization and lipid metabolism genes in skeletal muscle in vitro. Plasma metabolic profiles obtained during exercise provide signatures of exercise performance and cardiovascular disease susceptibility, in addition to highlighting molecular pathways that may modulate the salutary effects of exercise.
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Increased drug use and STI risk with injection drug use among HIV-seronegative heterosexual methamphetamine users.
J Psychoactive Drugs
PUBLISHED: 05-15-2010
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Methamphetamine (MA) use has been found to be associated with increased risk of HIV and sexually transmitted infections (STI) among men having sex with men, but it is unknown whether those who inject MA are at greater risk for these infections than those who administer MA by other routes. Furthermore, comparable data from heterosexual MA users are lacking. We investigated whether the HIV and STI risks of male and female heterosexual MA users who inject MA differ from those of comparable users who do not inject. Between 2001 and 2005, we interviewed 452 HIV-negative men and women aged 18 and older who had recently used MA and engaged in unprotected sex. Their mean age was 36.6 years; 68% were male; ethnicity was 49.4% Caucasian, 26.8% African-American, and 12.8% Hispanic. Logistic regression identified factors associated with injecting MA. Compared to non-IDU, IDU were more likely to: be Caucasian; be homeless; have used MA for a longer period and used more grams of MA in the last 30 days; have a history of felony conviction; and report a recent STI. HIV and STI prevention interventions should be tailored according to MA users method of administration.
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Relation of QRS width in healthy persons to risk of future permanent pacemaker implantation.
Am. J. Cardiol.
PUBLISHED: 01-12-2010
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In the setting of acute myocardial infarction, prolongation of the QRS interval on electrocardiography identifies patients at risk for needing permanent pacemaker implantation. However, the implications of prolonged QRS intervals in healthy subjects are unclear, especially given that the QRS prolongation encountered in this setting is typically mild. The aim of this study was to assess the relation between QRS duration and incident pacemaker implantation in a community-based cohort of 8,311 subjects (mean age 54 years, 55% women) who attended 17,731 routine examinations with resting 12-lead electrocardiography. QRS duration was analyzed as a continuous and a categorical variable (<100, 100 to <120, and > or =120 ms). During up to 35 years of follow-up, 157 participants (56 women) developed need for permanent pacemakers. In multivariable Cox regression models adjusting for cardiovascular risk factors and previous myocardial infarction or heart failure, mild QRS prolongation was associated with a threefold risk for pacemaker implantation (adjusted hazard ratio 2.90, 95% confidence interval 1.81 to 4.66, p <0.0001), and bundle branch block was associated with a fourfold risk for pacemaker implantation (hazard ratio 4.43, 95% confidence interval 2.94 to 6.68, p <0.0001). Each standard deviation increment in QRS duration (11 ms) was associated with an adjusted hazard ratio of 1.14 (95% confidence interval 1.11 to 1.18, p <0.0001) for pacemaker placement. This association remained significant after excluding subjects with QRS durations > or =120 ms. In conclusion, subjects with prolonged QRS durations, even without bundle branch block, are at increased risk for future pacemaker implantation. Such individuals may warrant monitoring for progressive conduction disease.
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Adiposity, cardiometabolic risk, and vitamin D status: the Framingham Heart Study.
Diabetes
PUBLISHED: 10-15-2009
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Because vitamin D deficiency is associated with a variety of chronic diseases, understanding the characteristics that promote vitamin D deficiency in otherwise healthy adults could have important clinical implications. Few studies relating vitamin D deficiency to obesity have included direct measures of adiposity. Furthermore, the degree to which vitamin D is associated with metabolic traits after adjusting for adiposity measures is unclear.
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Differences in sexual risk behaviors among male and female HIV-seronegative heterosexual methamphetamine users.
Am J Drug Alcohol Abuse
PUBLISHED: 07-11-2009
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Despite increased awareness and attention towards methamphetamine (MA) use among men who have sex with men (MSM), few studies have examined behaviors and effects of MA use among heterosexual populations.
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Long-term outcomes in individuals with prolonged PR interval or first-degree atrioventricular block.
JAMA
PUBLISHED: 06-25-2009
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Prolongation of the electrocardiographic PR interval, known as first-degree atrioventricular block when the PR interval exceeds 200 milliseconds, is frequently encountered in clinical practice.
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The rate of sexually transmitted infections in ED patients with vaginal bleeding.
Am J Emerg Med
PUBLISHED: 06-06-2009
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Early diagnosis of sexually transmitted infections (STI) such as Chlamydia trachomatis (CT) and Neisseria gonorrhoea (NG) is crucial in reducing complications. Vaginal bleeding (VB) has been suggested as a possible presentation of STI.
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Myocardial tissue tagging with cardiovascular magnetic resonance.
J Cardiovasc Magn Reson
PUBLISHED: 04-23-2009
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Cardiovascular magnetic resonance (CMR) is currently the gold standard for assessing both global and regional myocardial function. New tools for quantifying regional function have been recently developed to characterize early myocardial dysfunction in order to improve the identification and management of individuals at risk for heart failure. Of particular interest is CMR myocardial tagging, a non-invasive technique for assessing regional function that provides a detailed and comprehensive examination of intra-myocardial motion and deformation. Given the current advances in gradient technology, image reconstruction techniques, and data analysis algorithms, CMR myocardial tagging has become the reference modality for evaluating multidimensional strain evolution in the human heart. This review presents an in depth discussion on the current clinical applications of CMR myocardial tagging and the increasingly important role of this technique for assessing subclinical myocardial dysfunction in the setting of a wide variety of myocardial disease processes.
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Age-related left ventricular remodeling and associated risk for cardiovascular outcomes: the Multi-Ethnic Study of Atherosclerosis.
Circ Cardiovasc Imaging
PUBLISHED: 03-26-2009
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Age-related alterations of left ventricular (LV) structure and function that may predispose to cardiovascular events are not well understood.
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Predictors of initial nontherapeutic anticoagulation with unfractionated heparin in ST-segment elevation myocardial infarction.
Circulation
PUBLISHED: 02-23-2009
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Although weight-based nomograms have improved the efficacy and safety of dosing unfractionated heparin in ST-segment elevation myocardial infarction, achieving therapeutic anticoagulation in practice remains challenging.
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Superior vena cava syndrome: a contemporary review of a historic disease.
Cardiol Rev
PUBLISHED: 02-13-2009
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Superior vena cava (SVC) syndrome is a historic entity that is reemerging as an important, albeit still uncommon, contemporary vascular disease condition. The causes of SVC syndrome have evolved dramatically over the last century: whereas the majority of originally described cases were due to infection, contemporary presentations are now predominantly associated with the presence of an intravascular device and/or mediastinal malignancy. Multiple underlying pathologic mechanisms often coexist to confer risk for SVC syndrome. Although the diagnosis is still best made at the bedside, advanced imaging modalities may be used to clarify etiology, grade severity, and facilitate intervention. Treatment of SVC syndrome often requires a combination of noninvasive and invasive therapies. With regard to invasive strategies, endovascular approaches to revascularization are now considered first-line given their relative safety and efficacy. Fortunately, both endovascular and open surgical interventions can offer definitive therapy in a majority of cases.
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Self-administered vaginal swabs are a feasible alternative to physician-assisted cervical swabs for sexually transmitted infection screening in the emergency department.
Acad Emerg Med
PUBLISHED: 02-11-2009
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Screening for sexually transmitted infections (STIs) in the emergency department (ED) is limited by the need for pelvic examination. It has been suggested that using self-administered vaginal swabs (SAVS) for this purpose may save time and resources and may be more comfortable for patients. Objectives: The objective was to test the feasibility of using SAVS for STI screening in the ED.
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Blood pressure tracking over the adult life course: patterns and correlates in the Framingham heart study.
Hypertension
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The extent to which select vascular risk factors differentially influence blood pressure (BP) is incompletely understood. Thus, we used multilevel modeling to analyze serial BP measurements using 21 732 person-observations obtained on Framingham Heart Study participants (mean age, 38 years, 52% women; 4993 unique individuals) over a 28-year period. We related longitudinal tracking of each BP measure (systolic BP, diastolic BP, mean arterial pressure, and pulse pressure) to age, sex, body mass index, smoking, diabetes mellitus, total/high-density lipoprotein cholesterol ratio, and heart rate. In multivariable-adjusted analyses, we observed that older age, male sex, greater body mass index, and higher heart rate were positively associated with increase in all BP measures (P<0.0001). Notably, higher total/high-density lipoprotein cholesterol ratio was associated with greater mean arterial pressure (P<0.01). Conversely, diabetes mellitus and smoking were associated with higher pulse pressure (P<0.01). We also observed effect modification by sex: the increase in pulse pressure with age and body mass index was more pronounced in women compared with men (P<0.0001). All BP measures tracked at higher levels in both men and women with multiple vascular risk factors. Taken together, our longitudinal observations in a large community-based sample demonstrate a greater pulsatile load in women than in men with increasing age. We also observed a differential impact of select vascular risk factors on the individual components of BP, underscoring distinct regulation of these measures over the life course.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.