Associations of Leg Fat Accumulation with Adiposity-Related Biological Factors and Risk of Metabolic Syndrome

OBJECTIVE To examine associations between regional fat mass (FM) distribution and cardiometabolic risk factors among ethnic minority groups, such as non-Hispanic blacks and Hispanics. DESIGN AND METHODS The associations among 8,802 US residents who participated in the 1999-2004 US National Health and Nutrition Examination Survey were examined. Body composition was measured using dual-energy X-ray absorptiometry. Leg fat indices included leg FM, leg FM percent (FM%), leg to whole body FM ratio (leg/whole), and leg to trunk FM ratio (leg/trunk). The correlation between leg fat indices and adiposity-related risk factors, as well as the association of these indices with metabolic syndrome (MetS) was evaluated. RESULTS After adjusting for covariates including age, gender, and trunk FM or trunk FM%, higher leg FM and leg FM% were, in general, correlated favorably with adiposity-related risk factors and associated with lower odds of MetS in all ethnicities, including non-Hispanic whites and blacks and Hispanic groups. In addition, in all multivariate-adjusted models, leg/whole and leg/trunk ratios were strongly associated with lower levels of most risk factors and decreased odds of MetS in these ethnicities (all odds ratios comparing extreme quintiles < 0.1). CONCLUSIONS Results show that leg fat accumulation is inversely associated with adiposity-related biological factors and risk of MetS in both whites and ethnic groups, suggesting that regional fat distribution plays an important role in the etiology of adiposity-related diseases in these populations.