Abstract MP81: Differences in Body Composition Between Metabolically Healthy Obese and Metabolically Abnormal Obese Phenotypes

Abstract

Purpose: Studies of body composition between metabolically healthy obese (MHO) and metabolically abnormal obese (OA) cardiometabolic profiles have been limited to mostly small sample sizes and postmenopausal women. Thus, the purpose is to determine whether measures of body composition differ between MHO and OA using men and women across a wide age range. Methods: The sample included 395 obese (≥30 kg/m 2 ) adults (66% women; 62% white, 38% African American) from the Pennington Center Longitudinal Study, 18-68 years of age (mean±SD: 40.6±13.2). Adults were classified as OA (≥2 cardiometabolic risk factors: blood pressure ≥130/85 mmHg; triglycerides ≥150 mg/dL, high density lipoprotein cholesterol men <40, women <50 mg/dL; fasting glucose ≥100 mg/dL) or MHO (<2 cardiometabolic risk factors). Whole-body bone mineral density (BMD; g/cm 2 ), bone mineral content (BMC; kg), percent body fat (%), fat mass (kg), lean mass (kg) and trunk adipose tissue mass (kg) were measured with dual-energy x-ray absorptiometry. Visceral (VAT; cm 2 ), subcutaneous (SAT; cm 2 ), and total abdominal adipose tissue (TAT; cm 2 ) were measured with computed tomography. Non-normally distributed variables were log transformed for analysis (lean mass, VAT, BMD and BMC) but means were reverse-transformed for presentation of results. Gender-specific general linear regression models (men: n=136; women: n=259) were used to determine differences in body composition between MHO (men: n=57; women n=153) and OA (men: n=79; women n=106) controlling for age, race, smoking status, and menopause status (in women). Results: In men, OA had greater fat mass (OA vs. MHO mean±SE; p-value for difference: 31.4±1.2 vs. 28.6±1.2 kg; p=0.02) and greater trunk adipose tissue (16.5±0.7 vs. 14.3±0.8 kg; p=0.002) compared with MHO, but no significant differences between MHO and OA profiles for BMD, BMC, % fat, lean mass, VAT, SAT, or TAT. Women with OA profiles had greater lean mass (54.4±1.0 vs. 51.5±1.0 kg; p<0.0001), greater VAT (119.4±1.1 vs. 95.7±1.1 cm 2 ; p<0.0001) and greater trunk adipose tissue (18.0±0.5 vs. 17.1±0.5 kg; p=0.03) when compared with MHO women, with no significant differences between MHO and OA for BMD, BMC, % fat, fat mass, SAT or TAT. Conclusion: OA and MHO cardiometabolic profiles are characterized by differences in body composition that vary by gender. Men have differences in overall and trunk adipose tissue while women have differences in lean mass and centralized fat (VAT and trunk). Future studies should confirm these results in different race and age groups.