Differences in the association between serum leptin levels and body mass index in black and white women: a report from the Southern Community Cohort Study.

ABSTRACT

BACKGROUND/AIMS: Leptin may be an important link between obesity and many high-burden diseases, including cancer and cardiovascular disease, but leptin levels and correlates in individuals of diverse racial backgrounds have not been well characterized despite racial differences in incidence and mortality patterns for many obesity-related diseases. METHODS: In a cross-sectional study of 915 white and 892 black women enrolled in the Southern Community Cohort Study (age 40-79 years, half postmenopausal), serum leptin levels were compared between the race groups and across categories of body mass index (BMI). Potential correlates of leptin were assessed via race-stratified linear regression models. RESULTS: Blacks had higher unadjusted leptin levels than whites (geometric mean 22.4 vs. 19.0 ng/ml; p < 0.0001). Leptin increased with increasing BMI, and racial differences in leptin were most pronounced in women with BMI ≥25. Significant correlates of leptin included BMI, age, alcohol consumption, cigarette smoking, diabetes (both races) and fat consumption (black women only). Leptin remained higher in black women (22.7 vs. 18.8 ng/ml) after adjustment for these factors. CONCLUSIONS: Persistent racial differences in leptin concentrations exist after adjustment for BMI and other factors. Leptin assessment may be informative in future studies that investigate racial differences in the development of obesity-related diseases.