Sex Hormones and Abdominal Muscle Area and Radiodensity in Men: The Multi-Ethnic Study of Atherosclerosis.

Information on the associations of testosterone levels with abdominal muscle volume and quality in men is limited, while the role of estradiol and SHBG on these muscle characteristics are unclear. To investigate the association between fasting serum sex hormones and CT-derived abdominal muscle area and radiodensity in adult men. Cross sectional observational study using data from the Multi-Ethnic Study of Atherosclerosis. A community-based sample of 907 men aged 45-84 years; 878 men with complete data were included in the analysis. CT scans of the abdomen were interrogated for muscle characteristics. Multivariable linear regressions were used to test the associations. After adjustment, higher levels of both total testosterone and estradiol were associated with higher abdominal muscle area (1.79, 0.1-3.4, & 1.79, 0.4-3.2, respectively). In the final analyses, levels of total testosterone showed a positive association, while an inverse relationship was observed for SHBG with abdominal muscle radiodensity (0.3, 0.0-0.6, & -0.34, -0.6 - -0.1, respectively). Our results indicate a complex association between sex hormones and abdominal muscle characteristics in men. Specifically, total testosterone and estradiol were associated with abdominal muscle area, while only total testosterone was associated with muscle radiodensity and SHBG was inversely associated with muscle radiodensity.