Type 2 diabetes rate in transgender adults on HT similar to general population
Type 2 diabetes incidence rates do not differ between transgender adults after starting hormone therapy and cisgender adults, according to study findings published in The Journal of Clinical Endocrinology & Metabolism.
“Due to the decrease in insulin sensitivity in feminizing hormone therapy and an increase in insulin sensitivity in masculinizing hormone therapy, we hypothesized an increase in incident type 2 diabetes in transgender women and a decrease in transgender men,” Martin den Heijer, MD, PhD, professor in the department of internal medicine, division of endocrinology at Amsterdam UMC, University of Amsterdam in the Netherlands, and colleagues wrote. “However, in the present uniquely large cohort study including 4,099 transgender individuals, we found no clear differences in the incidence of type 2 diabetes in transgender women and transgender men after initiation of hormone therapy.”
Researchers conducted a retrospective study of transgender adults in the Amsterdam Cohort of Gender Dysphoria, which includes all people who visited a gender identity clinic at Amsterdam UMC between 1972 and 2018. Adults who began HT at age 17 years or older and did not use pubertal blockers prior to HT were included in the analysis. Due to the lack of a central registry for diabetes diagnosis, type 2 diabetes cases were identified through the first disposal of a glucose-lowering agent as recorded in the National Civil Record Registry from 2007 to 2018. Standardized incidence ratios were calculated to compare type 2 diabetes incidences among transgender women and transgender men with adults with the same birth sex in the general population.
The study included 2,585 transgender women and 1,514 transgender men. Transgender women had 4.5 cases of type 2 diabetes per 1,000 person-years, and transgender men had 3.4 cases per 1,000 person-years. Incidence rates for transgender women and transgender men did not differ compared with cisgender adults, according to the researchers.
“These reassuring results refute the concerns of increased type 2 diabetes risk in transgender women raised in previous reports,” the researchers wrote. “In transgender men, the risk of type 2 diabetes tended to be higher (although no statistical difference was observed) compared to women in the general population, which is in contrast to the hypothesized decreased risk due to increases in peripheral insulin sensitivity.”
Each 1-point increase in BMI at HT initiation was associated with an increased risk for developing type 2 diabetes in transgender women (HR = 1.12; 95% CI, 1.06-1.19) and transgender men (HR = 1.09; 95% CI, 1.01-1.18). Transgender men had an increased risk for type 2 diabetes with each 5-year increase in age (HR = 1.11; 95% CI, 1.01-1.23). There were no increased risks for diabetes with smoking or alcohol use, and no comorbidities were associated with diabetes risk at the start of HT.
“As incidence rates of type 2 diabetes in transgender individuals did not differ much from rates in the general population, we thus do not recommend routine additional screening for type 2 diabetes in transgender individuals,” the researchers wrote. “With regard to cardiometabolic risk, the current Endocrine Society guidelines for transgender care only recommends routine evaluation of cholesterol. To add to this, it may still be beneficial to evaluate fasting glucose in older, obese transgender individuals for whom primary care is not readily available. Otherwise, the general focus should remain on counseling overweight patients on the importance of lifestyle management during clinic visits.”