Incident Diabetes Risk Is Not Increased in Transgender Individuals Using Hormone Therapy

Context In trans women receiving hormone therapy, body fat and insulin resistance increases, with opposite effects in trans men. These metabolic alterations may affect the risk of developing type 2 diabetes in trans women and trans men. Context We aimed to compare the incidence of type 2 diabetes of adult trans women and trans men during hormone therapy with rates from their birth-assigned sex in the general population. Methods Retrospective data from the Amsterdam Cohort of Gender Dysphoria with transgender individuals on hormone therapy between 1972 and 2018 were linked to a nationwide health data registry. Because no central registry of diabetes is available, the occurrence of diabetes was inferred from the first dispense of a glucose-lowering agent. Standardized incidence ratios (SIR) were computed for trans women and trans men in comparison with the same birth sex from the general population. Results Compared with their birth-assigned sex in the general population, no difference in the incidence of type 2 diabetes mellitus was observed in trans women (N = 2585, 90 cases; SIR 0.94; 95% CI, 0.76-1.14) or trans men (N = 1514, 32 cases; SIR 1.40; 95% CI, 0.96-1.92). Conclusion Despite studies reporting an increase in insulin resistance in feminizing hormone therapy and a decrease in insulin resistance in masculinizing hormone therapy, the incidence of diabetes in transgender individuals after initiation of hormone therapy was not different compared with the general population.