Differential Association of Sex Hormones with Metabolic Parameters and Body Composition in Men and Women from the United States.

Sex hormones impact body composition. Data on the specific impact of each hormone on different body depots in men and women are scarce. The aim of this study is to evaluate the association between testosterone, estradiol and body fat distribution in the general population. This is a population-based cross-sectional study based on data from the 2013-2016 cycles of the National Health and Nutrition Examination Survey. Dual energy X-ray absorptiometry (DXA) and liquid chromatography tandem mass spectrometry were performed on participants aged 18-59 years to evaluate body composition and sex hormone levels, respectively. Weighted multivariable linear regression analyses were performed to evaluate the association between these parameters after adjustment for potential confounders. A total of 6655 participants (3309 males and 3346 females) was included in the analysis. Men with lower testosterone levels were older, had a higher body mass index (BMI) and had a generally unfavorable metabolic profile, while no specific trends were found in women. Among men, testosterone was positively associated with lean body mass and was negatively associated with fat mass and the android/gynoid (A/G) ratio, while an opposite trend was found for estradiol. Among women, testosterone did not impact body composition, while estradiol levels were positively associated with lean mass and were negatively associated with fat mass. Our results support the notion that the impact of different sex hormones on specific fat depots varies substantially between men and women.