Protective effects for transgender females?
Transgender females showed as much as a 47% decrease in the prevalence of stage 2 hypertension, from 19% to 10%, within 2 to 4 months of treatment with gender-affirming hormone therapy (P = .001), and the rate declined further to 8% at 11 to 21 months, suggesting a protective effect of the treatment.
“The rate of stage 2 hypertension did drop in transgender feminine individuals, which could be protective and lower their risk for cardiovascular events,” Dr. Irwig said.
“This was not a surprise, as lowering testosterone and the use of spironolactone can lower blood pressure,” he noted.
Exceptions in both groups
Of note, a sizable proportion of patients had blood pressure changes that were in fact the opposite of the patterns seen in the majority of their gender group.
Specifically, while 42% to 53% of the transgender females had systolic blood pressure readings of at least 5 mm Hg lower than their baseline readings, up to 32% had increases of at least 5 mm Hg compared to baseline readings.
Likewise, whereas 41% to 59% of transgender males had increases of at least 5 mm Hg compared with baseline, up to 35% had levels that were at least 5 mm Hg lower than baseline.
“It was a surprise that over a quarter of individuals had changes opposite to the mean changes,” Dr. Irwig said.
The differing blood pressure changes underscore that “more research is needed to determine which formulations of estrogen, testosterone, and antiandrogens are optimal regarding blood pressure and cardiovascular health, especially in older individuals,” the authors note.
Gender-affirming hormone therapy formulations differ
Various formulations for gender-affirming hormone regimens are available, including oral, transdermal, sublingual, and intramuscular preparations.
In the study, 77% to 91% of transgender males were on intramuscular testosterone injections, with the rest on transdermal formulations, and 92% of transgender female patients were started on oral estradiol, with mean doses generally increasing over time.
The study’s results are consistent with evidence from other studies, with 7 of 8 involving transgender males showing mean increases in systolic blood pressure ranging from 1 to 14 mm Hg.
Previous research supports cardiovascular risk
As reported by this news organization, other emerging research on cardiovascular risks to transgender people include a recent study showing more than 10% of transgender males were found to have hematocrit levels that could put them at risk for blood clots.
And further research on transgender youth also shows concerning elevations in lipids and other cardiovascular risks.
The authors have disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.