Cardiovascular outcomes in transgender individuals in Sweden after initiation of gender-affirming hormone therapy

Aims We compared the incidence of cardiovascular disease (CVD) in transgender participants with a diagnosis of gender dysphoria (GD) with and without gender-affirming hormone therapy (GAHT) to the incidence observed in the general population. Methods and results The population-based cohort included all individuals >10 years in Sweden linked to Swedish nationwide healthcare Registers (2006-16). Two comparator groups without GD/GAHT were matched (1:10) on age, county of residence, and on male and female birth-assigned sex, respectively. Cox proportional models provided hazard ratios (HRs) and 95% confidence intervals (CI) for CVD outcomes. Among 1779 transgender individuals [48% birth-assigned males (AMAB), 52% birth-assigned females (AFAB)], 18 developed CVD, most of which were conduction disorders. The incidence of CVD for AFAB individuals with GD was 3.7 per 1000 person-years (95% CI: 1.4-10.0). Assigned male at birth individuals with GD had an incidence of CVD event of 7.1 per 1000 person-years (95% CI: 4.2-12.0). The risk of CVD event was 2.4 times higher in AMAB individuals (HR: 2.4, 95% CI: 1.3-4.2) compared with cisgender women, and 1.7 higher compared with cisgender men (HR: 1.7, 95% CI: 1.0-2.9). Analysis limited to transgender individuals without GAHT yielded similar results to those with GAHT treatment. Conclusion The incidence of CVD among GD/GAHT individuals was low, although increased compared with matched individuals without GD and similar to the incidence among GD/no GAHT individuals, thus not lending support for a causal relationship between treatment and CVD outcomes. Larger studies with longer follow-up are needed to verify these findings, as well as possible effect modification by comorbidity.

Automated summary

This study compared the incidence of cardiovascular disease (CVD) in transgender individuals with gender dysphoria (GD) who received gender-affirming hormone therapy (GAHT) with those without GAHT and the general population. The results showed that the incidence of CVD was low among transgender individuals with GD/GAHT, although it was higher compared to those without GD and similar to those with GD but no GAHT. This suggests that there may not be a causal relationship between GAHT treatment and CVD outcomes. Larger studies with longer follow-up are needed to confirm these findings.