UCLA

Objective

To investigate whether leptin and adiponectin are associated with body fat composition in a South Asian population independent of metabolic variables.

Design

Cross-sectional study.

Subjects

150 South Asian men and women, between the ages of 45-79 years, in the San Francisco Bay Area without pre-existing clinical cardiovascular disease.

Measurements

Blood samples were obtained to measure glucose metabolism variables, lipid profiles and adipokines. Total body fat was determined using dual-energy X-ray absorptiometry. Abdominal computed tomography was used to measure subcutaneous, visceral and hepatic fat.

Results

Average body mass index (BMI) was overweight at 26.1±4.6 kg m(-2) and did not differ by sex. However, women had significantly more total body fat (P<0.001) and subcutaneous fat (P<0.001) than men, whereas men had significantly more visceral fat (P<0.001) and hepatic fat (P=0.04) than women. Women had significantly higher levels of adiponectin (P<0.01) and leptin (P<0.01). In sex-stratified analyses, leptin was strongly associated with all-body composition measures in women (P<0.05) as well as in men (P<0.05 except for hepatic fat), whereas there was an insignificant trend towards an inverse association between adiponectin and body composition in both women and men, which was significant in combined bivariate analyses. In multivariate analyses, leptin was strongly associated with all measures of adiposity, including BMI (P<0.001), total body fat (P<0.001), visceral fat (P<0.001) and hepatic fat (P=0.01). However, adiponectin's inverse association with adiposity was significantly attenuated by high-density lipoprotein (HDL), triglycerides and insulin resistance. The association between adipokines and diabetes was markedly attenuated after adjusting for body composition.

Conclusion

Despite only modestly elevated BMI, South Asians have elevated levels of total and regional adiposity. Leptin is strongly associated with adiposity, whereas adiponectin's association with adiposity is attenuated by metabolic variables in South Asians. Adipokines in association with adiposity have an important role in the development of diabetes.