Sex Steroids Regulate Liver Fat Content and Body Fat Distribution in Both Men and Women: A Study in Transgender Persons

Abstract

Abstract Context Liver fat content and visceral fat volume are associated with insulin resistance and cardiovascular disease and are higher in men than in women. Objective To determine the effect of estradiol and testosterone treatment on liver fat and visceral fat in transgender persons. Design Open-label intervention study (SHAMVA) with a 1-year follow-up. Setting Gender clinic in a hospital. Patients 8 trans women and 18 trans men receiving hormone treatment. Interventions Trans women received an antiandrogen and after 6 weeks estradiol was added. Trans men were randomized to receive triptorelin, testosterone, and anastrozole for 12 weeks or triptorelin and testosterone for 12 weeks, followed by only testosterone until week 52. Main outcome measures Liver fat content, visceral and abdominal subcutaneous fat volume, measured by magnetic resonance spectrometry or imaging at baseline, 6, 8, 18, and 58 weeks in transwomen or at baseline; at 6 and 12 weeks in trans men with anastrozole; and at 52 weeks in trans men without anastrozole. Results In trans women, liver fat content decreased by 1.55% (−2.99 to −0.12) after 58 weeks, compared to week 6. Visceral fat did not change. In trans men with anastrozole, the liver fat content and visceral fat volume did not change. In trans men without anastrozole, after 52 weeks, liver fat content increased by 0.83% (0.14 to 1.52) and visceral fat volume increased by 34% (16 to 51). Conclusions Sex hormones regulate liver fat content and visceral fat in men and women.