Visceral Fat and Race-Dependent Health Risks in Obese Nondiabetic Premenopausal Women
ABSTRACT Our previous finding that a waist-to-hip ratio (WHR) >0.85 was not associated with similar health risks in black, compared with white, obese premenopausal non-diabetic women of similar fatness is attributed to either 1) a different relationship between WHR and visceral adiposity or 2) differences in the relationship between visceral adiposity and the metabolic abnormalities of obesity. We measured visceral (VAT) and subcutaneous adipose tissue (SCAT) areas at midwaist in 25 black and 25 white obese nondiabetic pre-menopausal women with similar BMI, percentage body fat, and wide range of WHR (0.7-0.95 for black women and 0.7-0.9 for white women) and then compared insulin sensitivity index (SI), glucose and insulin areas under the 2-h curve (AUCs) during an oral glucose tolerance test (OGTT), and blood lipids in the two groups before and after adjustments for total body and visceral adiposity. After adjusting for total body fat mass (FM), obese black women had significantly less VAT (by 32 cm2) and lower VAT/SCAT for any given WHR. The regression equations predicting the SI the glucose and insulin AUCs, and the triglyceride and HDL cholesterol levels from regional adipose tissue measurements (VAT, SCAT, or VAT/SCAT) and from total body fat (FM or percentage body fat) had slopes that were not significantly different for black and white women. LDL cholesterol levels were independently related to VAT in black but not in white women. The black women had a similar SI insulin AUC, and triglyceride levels but significantly lower glucose AUC and higher HDL cholesterol levels (P < 0.001), after adjusting for VAT and FM. Regression analysis of the pooled data showed that high VAT and high VAT/SCAT, but not SCAT, predicted lower SI higher glucose and insulin AUCs during OGTT, and higher triglyceride levels, independent of total adiposity. We conclude that while increases in VAT and VAT/SCAT adversely affect metabolism in both black and white obese premenopausal women, similar levels of total body and visceral adiposity are associated with different metabolic risk factors in these groups.
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- "One explanation for the increased risk of GDM observed at lower cutpoints for BMI among Koreans could be a higher proportion of visceral fat compared to overall BMI among Koreans . While Korean and other east Asian women have not been compared directly to other racial/ethnic groups, Korean women may have relatively greater proportions of visceral fat for specific levels of BMI compared to non-Hispanic whites; such racial/ethnic differences in proportions of visceral fat to body weight have been observed between other race/ethnicities . Korean premenopausal women specifically have lower correlations between visceral fat and anthropometric measurements such as waist circumference compared to Korean postmenopausal women or men . "
ABSTRACT: Gestational diabetes mellitus (GDM) reflects defects in insulin secretion in response to the metabolic demands of pregnancy. While GDM is increasingly common worldwide due in large part to the obesity epidemic, its frequency is relatively low in Korean women. In this report, the prevalence and risk factors for GDM, perinatal outcomes, and postpartum course are compared in non-Korean and Korean women. While Koreans and non-Koreans with GDM share pathophysiology and complications, there may be differences in the role of obesity and thus the effectiveness of interventions targeting obesity in GDM women. Further investigations of the effectiveness of weight loss interventions and pharmacotherapy specifically among Korean women are needed. Dietary and other lifestyle data from Korean populations could inform prevention and treatment strategies in other countries which suffer from significantly higher prevalences of GDM.Diabetes & metabolism journal 02/2014; 38(1):1-12. DOI:10.4093/dmj.2014.38.1.1
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- "A functional polymorphism representing a T-to-C substitution at the -492 position of this gene has been associated with waist circumference and lower levels of plasma APOA-II in European men , suggesting that genetic variation at the APOA2 may be associated with body fat distribution phenotypes. Lower levels of visceral adipose tissue (VAT), both absolute and relative to their total body fat, have been reported in African-American compared with white women [5, 6], which may be related to differences in genetic make-up between women of different ethnic backgrounds. "
ABSTRACT: Objectives. This study aims to analysis the relationship between c.-492T>C polymorphism in APOA2 gene and the risk for obesity in a sample of Egyptian adolescents and investigates its effect on body fat distribution and lipid metabolism. Material and Methods. A descriptive, cross-sectional study was conducted on 303 adolescents. They were 196 obese and 107 nonobese, aged 16-19 years old. Variables examined included body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR), systolic and diastolic blood pressure (BP), body fat percentage (BF%), abdominal visceral fat layer, and dietary intake. Abdominal visceral fat thickness was determined by ultrasonography. The polymorphism in the APOA2 c.-492T>C was analyzed by PCR amplification. Results. Genotype frequencies were in Hardy-Weinberg equilibrium. The frequency of the mutant C allele was significantly higher in obese cases compared to nonobese. After multivariate adjustment, waist, BF% and visceral adipose layer, food consumption, and HDL-C were significantly higher in homozygous allele CC carriers than TT+TC carriers. Conclusions. Homozygous individuals for the C allele had higher obesity risk than carriers of the T allele and had elevated levels of visceral adipose tissue and serum HDL-C. Moreover, the study shows association between the APOA2 c.-492T>C polymorphism and food consumption.Cholesterol 12/2013; 2013:289481. DOI:10.1155/2013/289481
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- "Prior studies also demonstrate puzzling differences in the characteristics of adiposity between African Americans and Caucasians.5,22–24 For example, African American women have less VAT and, therefore, more upper body subcutaneous adipose tissue (SAT) than Caucasian women,25,26 but they tend to be more insulin resistant.27 In fact, African Americans have worse cardiometabolic disease profiles overall: a higher incidence of hypertension, twice the prevalence of diabetes, and 2- to 3-fold greater incidences of coronary artery disease and stroke. "
ABSTRACT: Obesity is a threat to public health worldwide primarily due to the comorbidities related to visceral adiposity, inflammation, and insulin resistance that increase risk for type 2 diabetes and cardiovascular disease. The translational research portfolio that originally described these risk factors was significantly enhanced by imaging techniques, such as dual-energy X-ray absorptiometry (DEXA), computed tomography (CT), and magnetic resonance imaging (MRI). In this article, we briefly review the important contributions of these techniques to understand the role of body composition in the pathogenesis of obesity-related complications. Notably, these imaging techniques have contributed greatly to recent findings identifying gender and racial differences in body composition and patterns of body composition change during weight loss. Although these techniques have the ability to generate good-quality body composition data, each possesses limitations. For example, DEXA is unable to differentiate type of fat, CT has better resolution but provides greater ionizing radiation exposure, and MRI tends to require longer imaging times and specialized equipment for acquisition and analysis. With the serious need for efficacious and cost-effective therapies to appropriately identify and treat at-risk obese individuals, there is greater need for translational tools that can further elucidate the interplay between body composition and the metabolic aberrations associated with obesity. In conclusion, we will offer our perspective on the evolution toward an ideal imaging method for body composition assessment in obesity and weight loss, and the challenges remaining to achieve this goal.Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy 09/2010; 3:337-47. DOI:10.2147/DMSOTT.S9454