Endocrine Abstracts

Estrogens play a protective role on the peripheral vascular endothelium in both females and males, however, no studies have reported on the effects of estrogens on male coronary arterial reactivity. We investigated the effects of estrogen therapy on coronary and endothelial function in a group of male to female transsexuals (M-to-F).

Eight M-to-F transsexuals (group A), receiving oral estrogen therapy for 72 months were studied in comparison with 23 age-matched healthy controls subdivided into 3 groups: 8 women (group B), 7 men without cardiovascular risk factors (group C), and 8 men (group D) with a comparable cardiovascular risk of transsexuals. Coronary flow reserve (CFR), was assessed to investigate the coronary endothelium. Flow mediated dilation (FMD) was assessed on brachial artery after flow increase and after nitroglycerine administration. Cardiovascular risk factors (smoke, blood pressure, lipid profile) were recorded.

The average number of risk factors was significantly greater in transsexuals and group D than in groups B and C. Systolic blood pressure was higher in group A an D than in B. Total and HDL cholesterol levels were similar in all groups but LDL cholesterol and triglyceride levels were higher in group A and D than in group B and C. CFR was higher in transsexuals compared with group D, but significantly reduced compared with groups B and C.

FMD in transsexuals was higher, although not significantly, than in group D, whereas it was significantly reduced compared with group B and C. Response to nitroglycerine was similar in transsexuals and in group D, and significantly reduced compared to groups B and C.

Estrogen therapy in M-to-F transsexuals is not harmful in terms of peripheral vascular function and coronary endothelial function. A tendency toward small improvement of endothelial risk factors with respect to the general population seems to be produced by the treatment.