Prevalent and incident type 2 diabetes (T2D) risk may be higher among transfeminine (TF) persons compared with cisgender women but not cisgender men, according to a study in the Journal of Clinical Endocrinology & Metabolism.
The study also found there was little evidence linking T2D to gender-affirming hormone therapy (GAHT) in either TF or transmasculine (TM) people.
The findings are based on data from the Study of Transition Outcomes and Gender (STRONG), an electronic health record (EHR)-based population of transgender/ transgender diverse (TGD) persons receiving care at 3 health systems located in Northern California, Southern California, and Georgia. Data were obtained from 2006 through 2014, and follow-up was conducted through the end of 2016.
A total of 5002 TGD persons were included—2869 (57%) were TF and 2133 (43%) were transmasculine (TM). The TF participants were matched with 28,300 cisgender females (CF) and 28,258 cisgender males (CM). The TM group was matched with 20,997 CF and 20,964 CM referents. Among the TM patients, 21% were aged younger than 36 years vs 13% of TF patients, and 54% of TF persons and 60% of TM persons were non-Hispanic Whites.
Significantly higher odds were found for prevalent T2D in the full TF cohort vs CF referents, with an adjusted odds ratio estimate of 1.3 (95% CI, 1.1-1.5), according to logistic regression analyses.
The overall TF cohort had a moderately increased T2D rate compared with CF referents (hazard ratio [HR], 1.4; 95% CI, 1.1-1.8), but not compared with the CM group (HR, 1.2; 95% CI, 0.9-1.5), based on Cox proportional hazard analyses. The corresponding analyses for the TM group yielded HR (95% CI) estimates of 1.3 (0.9-1.8) and 1.2 (0.9-1.7) relative to the CF and CM reference cohorts, respectively.
The incidence of T2D per 1000 person-years was 9.3 (95% CI, 7.6-11.3) in all TF participants, and 5.9 (95% CI, 3.6-9.4) in TF participants who initiated gender-affirming hormone therapy (GAHT). The incidence rate estimates for TM participants were 6.2 (95% CI, 4.6-8.4) overall and 5.5 (95% CI, 3.1, 9.7) for those who initiated GAHT after the index date.
Among several study limitations noted by the investigators, the data were not collected at specified intervals and the number and frequency of clinical encounters was different among the participants. In addition, the algorithm that was used did not explicitly distinguish between type 1 diabetes (T1D) and T2D. Data were lacking for other T2D risk factors, such as family history, socioeconomic status, and adverse childhood experiences and gender minority stress. In particular, researchers noted other studies have shown sexual and gender minority stress may be related to a number of adverse clinical outcomes, including asthma, cardiovascular disease, elevated T2D risk, and poor glycemic control.
“There is little evidence that T2D occurrence in either TF or TM persons is attributable to GAHT use,” stated the study authors. “Whereas these findings provide reassurance, a more definitive conclusion regarding no effect of GAHT on T2D risk may require larger, more detailed studies with longer follow-up. In the meantime, clinicians should continue monitoring cardiometabolic status of the TGD individuals.”
Islam N, Nash R, Zhang Q, et al. Is there a link between hormone use and diabetes incidence in transgender people? Data from the STRONG cohort. J Clin Endocrinol Metab. First published online November 30, 2021; corrected and typeset December 2, 2021. doi:10.1210/clinem/dgab832