Abstract 1921: Body fatness and sex steroid hormone concentrations in US men – Results from NHANES III

Background: Obesity is associated with a variety of chronic diseases, including cancer, which may partly be explained by its influence on sex steroid hormone concentrations. However, different measures of obesity are not equally strongly associated with the risk of these diseases, and, thus, might also differently influence circulating levels of sex steroid hormones. Objective: To estimate and compare the associations of body mass index (BMI), waist circumference, and percent body fat with circulating sex steroid hormone levels. Methods: In our analysis, we included 1,256 men, aged 20+ years, who attended the morning examination session of the Third National Health and Nutrition Examination Survey (NHANES III; 1988-1991). Serum hormones were measured by immunoassay. Weight, height, and waist circumference were measured by trained staff. Percent body fat was estimated from bioelectrical impedance. Linear regression was used to estimate associations between body fatness measures and hormone levels adjusting for age, race/ethnicity, previously identified correlates of hormone levels, and the other hormones. Results. Total and free testosterone and sex hormone binding globulin (SHBG) concentrations decreased with increasing BMI, waist circumference, and percent body fat (all p-trend