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Showing papers by "Scott M. Grundy published in 2013"


Journal ArticleDOI
01 Sep 2013-Obesity
TL;DR: VAT and abdominal subcutaneous adipose tissues contribute to obesity but may have different metabolic and atherosclerosis risk profiles, and the associations with markers of cardiac and metabolic risk in a large, multiethnic, population‐based cohort of obese adults are determined.
Abstract: Objective Visceral (VAT) and abdominal subcutaneous (SAT) adipose tissues contribute to obesity but may have different metabolic and atherosclerosis risk profiles. We sought to determine the associations of abdominal VAT and SAT mass with markers of cardiac and metabolic risk in a large, multiethnic, population-based cohort of obese adults. Design and methods Among obese participants in the Dallas Heart Study, we examined the cross-sectional associations of abdominal VAT and SAT mass, assessed by magnetic resonance imaging (MRI) and indexed to body surface area (BSA), with circulating biomarkers of insulin resistance, dyslipidemia, and inflammation (n = 942); and with aortic plaque and liver fat by MRI and coronary calcium by computed tomography (n = 1200). Associations of VAT/BSA and SAT/BSA were examined after adjustment for age, sex, race, menopause, and body mass index. Results In multivariable models, VAT significantly associated with the homeostasis model assessment of insulin resistance (HOMA-IR), lower adiponectin, smaller LDL and HDL particle size, larger VLDL size, and increased LDL and VLDL particle number (p Conclusion VAT associated with an adverse metabolic, dyslipidemic, and atherogenic obesity phenotype. In contrast, SAT demonstrated a more benign phenotype, characterized by modest associations with inflammatory biomarkers and leptin, but no independent association with dyslipidemia, insulin resistance, or atherosclerosis in obese individuals. These findings suggest that abdominal fat distribution defines distinct obesity sub-phenotypes with heterogeneous metabolic and atherosclerosis risk.

357 citations


Journal ArticleDOI
TL;DR: Visceral adipose tissue, a marker of central adiposity, was independently associated with concentric LV remodeling and adverse hemodynamics, in contrast, lower body subcutaneous fat was associated with eccentric remodeling.
Abstract: Background— The relation of body fat distribution to left ventricular (LV) structure and function is poorly defined. Methods and Results— A total of 2710 participants without heart failure or LV dysfunction in the Dallas Heart Study underwent dual energy x-ray absorptiometry and MRI assessment of fat distribution, LV morphology, and hemodynamics. Cross-sectional associations of fat distribution with LV structure and function were examined after adjustment for age, sex, race, comorbidities, and lean mass. Mean age was 44 years with 55% women; 48% blacks; and 44% obese. After multivariable adjustment, visceral adipose tissue was associated with concentric remodeling characterized by lower LV end-diastolic volume (β=−0.21), higher concentricity (β=0.20), and wall thickness (β=0.09; P <0.0001 for all). In contrast, lower body subcutaneous fat was associated with higher LV end-diastolic volume (β=0.48), reduced concentricity (β=−0.50), and wall thickness (β=−0.28, P <0.0001 for all). Visceral adipose tissue was also associated with lower cardiac output (β=−0.10, P <0.05) and higher systemic vascular resistance (β=0.08, P <0.05), whereas lower body subcutaneous fat associated with higher cardiac output (β=0.20, P <0.0001) and lower systemic vascular resistance (β=−0.18, P <0.0001). Abdominal subcutaneous fat showed weaker associations with concentric remodeling and was not associated with hemodynamics. Among the subset of obese participants, visceral adipose tissue, but not abdominal subcutaneous fat, was significantly associated with concentric remodeling. Conclusions— Visceral adipose tissue, a marker of central adiposity, was independently associated with concentric LV remodeling and adverse hemodynamics. In contrast, lower body subcutaneous fat was associated with eccentric remodeling. The impact of body fat distribution on heart failure risk requires prospective study.

138 citations


Journal ArticleDOI
TL;DR: Men with high adiponectin/leptin ratios have better triglyceride profile and insulin sensitivity than men with a low ratio regardless of waist girth, and the ratio decreased progressively with the increase in the number of risk factors for metabolic syndrome.
Abstract: Background. High adiponectin/leptin ratio may be protective from metabolic risks imparted by high triglyceride, low HDL, and insulin resistance. Methods. This cross-sectional study examines plasma adipokine levels in 428 adult men who were subgrouped according to low (<6.5 μg/mL)and high (≥6.5 μg/mL)adiponectin levels or a low or high ratio of adiponectin/leptin. Results. Men with high adiponectin/leptin ratio had lower plasma triglyceride and higher HDL cholesterol than those with low ratio. Similarly, those with high adiponectin/leptin ratio had lower TG/HDL cholesterol ratio and HOMA2-IR than those with low ratio. In contrast, levels of adiponectin or the ratio of adiponectin/leptin did not associate with systolic blood pressure. But the ratio of adiponectin/leptin decreased progressively with the increase in the number of risk factors for metabolic syndrome. Conclusion. Adipokine levels may reflect adipose tissue triglyceride storage capacity and insulin sensitivity. Leptin is an index of fat mass, and adiponectin is a biomarker of triglyceride metabolism and insulin sensitivity. Men with high adiponectin/leptin ratios have better triglyceride profile and insulin sensitivity than men with a low ratio regardless of waist girth.

80 citations


Journal Article
TL;DR: This work investigated the associations of novel imaging markers of adiposity, including visceral adipose tissue (VAT) and abdominal subcutaneous adipOSE tissue (SAT) by magnetic resonance imaging, lower body sub cutaneous adipose tissues (LBAT)By dual-energy x-ray absorptiometry, and liver fat by magnetic Resonance spectroscopy with the risk for cardiovascular disease (CVD) events in a multiethnic cohort of obese adults.
Abstract: Background: Differences in body fat distribution may underpin heterogeneity in cardiovascular disease (CVD) risk associated with obesity. However, relative contributions of specific adipose tissue depots to CVD risk have not been fully explored. Methods: We analyzed data from obese (BMI ≥ 30 kg/m 2 ) participants in the Dallas Heart Study without baseline CVD who underwent dual energy x-ray absorptiometry and MRI assessment of adipose tissue distribution (visceral, abdominal subcutaneous, lower body subcutaneous) between 2000 and 2002. The composite outcome of incident and recurrent CVD events (CV death, myocardial infarction, stroke, coronary or peripheral artery revascularization, heart failure, or atrial fibrillation) was assessed over 8 years of follow-up. Associations between adipose depots and CVD events were assessed with multivariable-adjusted Cox proportional hazards models using the Wei-Lin-Weissfeld method for recurrent events. Results: The study cohort included 972 obese participants with mean age 44 yrs; 62% women; 54% African-Americans. 91 CVD events occurred in 68 participants (7.0%). After multivariable adjustment for age, sex, race, and traditional risk factors, visceral adipose tissue was independently associated with development of CVD (HR per 1 SD: 1.24 [95% CI 1.02, 1.50]), while lower body subcutaneous adipose tissue was inversely associated with CVD (HR per 1 SD: 0.73 [95% CI 0.54, 0.99], Figure). In contrast, no significant associations with CVD were observed for BMI, waist circumference, waist-hip ratio, or abdominal subcutaneous fat. Associations were consistent across components of the composite outcome and in age, sex, race, and BMI subgroups. Conclusions: Among obese adults, excess visceral adipose tissue was associated with higher CVD risk while increased lower body subcutaneous fat had a protective association. These findings highlight the biological importance of fat distribution with regard to CVD risk in obesity.

71 citations


Journal ArticleDOI
TL;DR: Intercorrelations among waist circumference, intraperitoneal fat (IPF), and subcutaneous abdominal fat (SAF) in ethnically diverse Dallas Heart Study and WC measures TAF reliably, but its association with IPF depends on IPF/ASF ratios that vary by gender and ethnicity.
Abstract: This study examines intercorrelations among waist circumference (WC), intraperitoneal fat (IPF), and subcutaneous abdominal fat (SAF) in ethnically diverse Dallas Heart Study consisting of 1538 women and 1212 men (50% Black). Correlations between fat depots and triglyceride or HOMA2-IR, biomarkers of metabolic syndrome, are also reported. Total abdominal fat (TAF), ASF, and IPF masses were measured by magnetic resonance imaging. The highest correlations with WC according to ethnicity and gender were noted for TAF (R (2) = 0.81 - 0.88) with progressively lower correlations with ASF (0.65-0.82) and IPF (0.29-0.85). The percentage of IPF relative to TAF was not significantly correlated with WC. For all WC categories, higher IPF/ASF ratios were associated with higher triglyceride levels. In contrast, differences in ratios had little or no association with HOMA2-IR. However, when all data were pooled, IPF was positively correlated with both triglyceride (r = 0.358 (men) and 0.363 (women)) and HOMA2-IR (r = 0.480 (men) and 0.517 (women)); after adjustment for ASF, IPF was still correlated with triglyceride (r = 0.353 (men) and 0.348 (women)) and HOMA2-IR (r = 0.290 (men) and 0.221 (women)). WC measures TAF reliably, but its association with IPF depends on IPF/ASF ratios that vary by gender and ethnicity.

70 citations


Journal ArticleDOI
TL;DR: The results strongly point to a common biological basis of the regulation of theregulation of the authors' appetite for tobacco and food, and thus the vulnerability to nicotine addiction and obesity, and the effect of single-nucleotide polymorphisms affecting body mass index (BMI).
Abstract: Smoking influences body weight such that smokers weigh less than non-smokers and smoking cessation often leads to weight increase. The relationship between body weight and smoking is partly explained by the effect of nicotine on appetite and metabolism. However, the brain reward system is involved in the control of the intake of both food and tobacco. We evaluated the effect of single-nucleotide polymorphisms (SNPs) affecting body mass index (BMI) on smoking behavior, and tested the 32 SNPs identified in a meta-analysis for association with two smoking phenotypes, smoking initiation (SI) and the number of cigarettes smoked per day (CPD) in an Icelandic sample (N=34 216 smokers). Combined according to their effect on BMI, the SNPs correlate with both SI (r=0.019, P=0.00054) and CPD (r=0.032, P=8.0 × 10−7). These findings replicate in a second large data set (N=127 274, thereof 76 242 smokers) for both SI (P=1.2 × 10−5) and CPD (P=9.3 × 10−5). Notably, the variant most strongly associated with BMI (rs1558902-A in FTO) did not associate with smoking behavior. The association with smoking behavior is not due to the effect of the SNPs on BMI. Our results strongly point to a common biological basis of the regulation of our appetite for tobacco and food, and thus the vulnerability to nicotine addiction and obesity.

65 citations


Journal ArticleDOI
01 Jan 2013-Obesity
TL;DR: The association between perceptions of neighborhood environment and obesity among 5,907 participants in the Dallas Heart Study, a multi‐ethnic, probability‐based sample of Dallas County residents was examined.
Abstract: Objectives: Although psychosocial stress can result in adverse health outcomes, little is known about how perceptions of neighborhood conditions, a measure of environment-derived stress, may impact obesity. The association between perceptions of neighborhood environment and obesity (defined as body mass index [BMI] ≥ 30 kg/m2) among 5,907 participants in the Dallas Heart Study, a multi-ethnic, probability-based sample of Dallas County residents was examined. Design and Methods: Participants were asked to respond to 18 questions about perceptions of their neighborhood. Factor analysis was used to identify three factors associated with neighborhood perceptions: neighborhood violence, physical environment, and social cohesion. Logistic regression analyses were performed to determine the relationship between each factor (higher quintile = more unfavorable perceptions) and the odds of obesity. Results: Decreasing age, income, and education associated with unfavorable overall neighborhood perceptions and unfavorable perceptions about specific neighborhood factors (P trend <0.05 for all). Increasing BMI was associated with unfavorable perceptions about physical environment (P trend <0.05) but not violence or social cohesion. After adjustment for race, age, sex, income, education, and length of residence, physical environment perception score in the highest quintile remained associated with a 25% greater odds of obesity (OR 1.25, [95% CI 1.03-1.50]). Predictors of obesity related to environmental perceptions included heavy traffic (OR 1.39, [1.17-1.64]), trash/litter in neighborhood (OR 1.27, [1.01-1.46]), lack of recreational areas (OR 1.21, [1.01-1.46]), and lack of sidewalks (OR 1.25, [95% CI 1.04-1.51]). Conclusions: Thus, unfavorable perceptions of environmental physical conditions are related to increased obesity. Efforts to improve the physical characteristics of neighborhoods, or the perceptions of those characteristics, may assist in the prevention of obesity in this community.

63 citations


Journal ArticleDOI
TL;DR: Zhang and colleagues used electronic health records to explore statin discontinuation rates and found low rates of discontinuation in women and high rates in men.
Abstract: Statins are among the most widely prescribed drugs, but discontinuation rates are relatively high. In this issue, Zhang and colleagues used electronic health records to explore statin discontinuati...

18 citations


Journal ArticleDOI
TL;DR: The validity of plasma noncholesterol sterols for the evaluation of cholesterol absorption in humans is called into question, and the campesterol/lathosterol ratio should better indicate cholesterol absorption than the sitosterol/cholesterol ratio.

16 citations


Book ChapterDOI
01 Jan 2013
TL;DR: Recent studies have shown that polyunsaturated fatty acids tend to reduce LDL cholesterol when replacing saturated fat in the diet, and this is a major factor affecting LDL levels.
Abstract: High blood cholesterol is one of the leading risk factors for atherosclerosis. Blood cholesterol level is affected by a number of factors, including genetics, diet, tobacco use, level of physical activity, age, and menopause. Cholesterol is carried in the blood by macromolecular complexes called lipoproteins, which consist of a protein moiety (apolipoprotein) and also include, besides cholesterol, phospholipids, and triacylglycerol. A key determinant of cardiovascular risk is low-density lipoprotein (LDL) blood concentration. In turn, dietary fat quality and quantity is a major factor affecting LDL levels. Recent studies have shown that polyunsaturated fatty acids tend to reduce LDL cholesterol when replacing saturated fat in the diet.

5 citations