Publications (208) View all
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Article: The geographic concentration of U.S adult obesity prevalence and associated social, economic, and environmental factors.
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ABSTRACT: Objective: This study used spatial statistical methods to test the hypotheses that county-level adult obesity prevalence in the United States is 1) regionally concentrated at significant levels, and 2) linked to local-level factors, after controlling for state-level effects. Design and Methods: Data were obtained from the Centers for Disease Control and Prevention (CDC) and other secondary sources. The units of analysis were counties. The dependent variable was the age-adjusted percentage of adults who were obese in 2009 (body mass index >30 kg/m(2) ). Results: The prevalence of county-level obesity varied from 13.5% to 47.9% with a mean of 30.3%. Obesity prevalence across counties was not spatially random: 15.8% belonged to high-obesity regions and 13.5% belonged to low-obesity regions. Obesity was positively associated with unemployment, outpatient healthcare visits, physical inactivity, female-headed families, black populations, and less education. Obesity was negatively correlated with physician numbers, natural amenities, percent ≥65 years, Hispanic populations, and larger population size. A number of variables were notable for not reaching significance after controlling for other factors, including poverty and food environment measures. Conclusions: The findings demonstrate the importance of local-level factors in explaining geographic variation in obesity prevalence, and thus hold implications for geographically targeted interventions to combat the obesity epidemic.Obesity 04/2013; · 4.28 Impact Factor -
Article: Prealbumin is Associated With Visceral Fat Mass in Patients Receiving Hemodialysis.
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ABSTRACT: OBJECTIVE: Albumin and prealbumin are associated with nutritional status and inflammatory status. Each has a residual effect on mortality outcomes when included in regression models that include the other. Prealbumin is increased in the obese mouse model as a consequence of stabilization of prealbumin by retinol binding protein 4 (RBP4) secreted by adipocytes. We carried out this study to establish the contribution of adiposity to prealbumin levels in prevalent patients receiving dialysis and the relationship of prealbumin to RBP4. DESIGN AND METHODS: We determined whether prealbumin was associated with adiposity in patients receiving hemodialysis (HD), controlling for the effects of inflammation and nutrition. We evaluated body composition in 48 prevalent patients receiving HD by magnetic resonance imaging (MRI), measuring total skeletal muscle mass (SM), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and serum albumin, prealbumin, RBP4, and interleukin-6 (IL-6) levels. We used normalized protein catabolic rate (nPCR) to report nutrition and separately analyzed the determinants of albumin and then of prealbumin by multiple stepwise regression. RESULTS: Thirty-two patients were women, 16 patients were diabetic, and median age and body mass index were 54.5 and 27.3 kg/m(2), respectively. Median total adipose tissue (TAT) was 24.3 kg and VAT was 3.25 kg. Prealbumin was positively associated with VAT, nPCR, and RBP4 and was negatively associated with IL-6; r(2) for the model was 0.64. By contrast, albumin was positively associated with nPCR and negatively associated with IL-6 but not with any measure of adiposity (r(2) for the model = 0.2). CONCLUSIONS: Prealbumin, like albumin, is associated with markers of nutrition (nPCR) and inflammation, but unlike albumin, prealbumin levels are positively associated with visceral adiposity.Journal of Renal Nutrition 04/2013; · 1.57 Impact Factor -
Article: Comparison of the Relationship Between Bone Marrow Adipose Tissue and Volumetric Bone Mineral Density in Children and Adults.
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ABSTRACT: Several large-scale studies have reported the presence of an inverse relationship between bone mineral density (BMD) and bone marrow adipose tissue (BMAT) in adults. We aim to determine if there is an inverse relationship between pelvic volumetric BMD (vBMD) and pelvic BMAT in children and to compare this relationship in children and adults. Pelvic BMAT and bone volume (BV) was evaluated in 181 healthy children (5-17yr) and 495 healthy adults (≥18yr) with whole-body magnetic resonance imaging (MRI). Pelvic vBMD was calculated using whole-body dual-energy X-ray absorptiometry to measure pelvic bone mineral content and MRI-measured BV. An inverse correlation was found between pelvic BMAT and pelvic vBMD in both children (r=-0.374, p<0.001) and adults (r=-0.650, p<0.001). In regression analysis with pelvic vBMD as the dependent variable and BMAT as the independent variable, being a child or adult neither significantly contribute to the pelvic BMD (p=0.995) nor did its interaction with pelvic BMAT (p=0.415). The inverse relationship observed between pelvic vBMD and pelvic BMAT in children extends previous findings that found the inverse relationship to exist in adults and provides further support for a reciprocal relationship between adipocytes and osteoblasts.Journal of Clinical Densitometry 03/2013; · 1.29 Impact Factor -
Article: Relationships between body roundness with body fat and visceral adipose tissue emerging from a new geometrical model.
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ABSTRACT: OBJECTIVE: To develop a new geometrical index that combines height, waist circumference (WC), and hip circumference (HC) and relate this index to total and visceral body fat. DESIGN AND METHODS: Subject data were pooled from three databases that contained demographic, anthropometric, dual energy X-ray absorptiometry (DXA) measured fat mass, and magnetic resonance imaging measured visceral adipose tissue (VAT) volume. Two elliptical models of the human body were developed. Body roundness was calculated from the model using a well-established constant arising from the theory. Regression models based on eccentricity and other variables were used to predict % body fat and % VAT. RESULTS: A body roundness index (BRI) was derived to quantify the individual body shape in a height-independent manner. Body roundness slightly improved predictions of % body fat and % VAT compared to the traditional metrics of body mass index (BMI), WC, or HC. On this basis, healthy body roundness ranges were established. An automated graphical program simulating study results was placed at http://www.pbrc.edu/bodyroundness. CONCLUSIONS: Body roundness index, a new shape measure, is a predictor of % body fat and % VAT and can be applied as a visual tool for health status evaluations.Obesity 03/2013; · 4.28 Impact Factor -
Article: Clinical utility of visceral adipose tissue for the identification of cardiometabolic risk in white and African American adults.
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ABSTRACT: BACKGROUND: Visceral adipose tissue (VAT) has been identified as a harmful fat depot, and sex and race differences in VAT have been reported in white and African Americans. OBJECTIVES: We determined the clinical utility of VAT in the identification of individuals at elevated cardiometabolic risk in white and African American adults and compared the clinical utility with measures obtained by using dual-energy X-ray absorptiometry (DXA) and anthropometric measures. DESIGN: The sample included 429 white women, 311 African American women, 406 white men, and 100 African American men who were 18-74 y of age. VAT was measured by using computed tomography, fat mass (FM) and percentage of body fat were measured by using DXA, and waist circumference (WC) and BMI were assessed. Receiver operating characteristic curves were used to compare the utility of measures in the identification of participants in the upper quintile of a continuous score derived from principal components analysis of fasting glucose, HDL cholesterol, triglycerides, and blood pressure. RESULTS: The clinical utility of measures varied across sex-by-race groups. In the overall sample, the areas under the curve were significantly higher for VAT and WC in comparison with the other indicators. Identified VAT thresholds were higher in white men (140 cm(2)) and women (141 cm(2)) than in African American men (82 cm(2)) and women (97 cm(2)). CONCLUSIONS: VAT and WC showed greater clinical utility than did other obesity measures. Because of the complexity of measuring VAT, the use of WC is recommended for the identification of adults with elevated cardiometabolic risk factors. The Pennington Center Longitudinal Study was registered at clinicaltrials.gov as NCT00959270.American Journal of Clinical Nutrition 01/2013; · 6.67 Impact Factor
