One could question whether these studies are applicable to the transsexual population. Evidence suggests that they are, certainly in respect to vasoreactivity, and probably in respect to cholesterol. The LDL cholesterol was lowered in all treatment groups. The HDL cholesterol was higher in all groups, but the highest levels were obtained in women taking estrogen alone or with micronized progesterone. Numerous other studies have confirmed the PEPI findings.
Most studies indicate that estrogen increases plasma triglyceride levels.
The significance of an elevated triglyceride in the absence of an elevated cholesterol is probably minimal, and the addition of progesterone seems to prevent much of the increase. These drugs included conjugated estrogens in 2.5 mg and 5 mg dosages, as well as thyroxine, niacin, and clofibrate. The estrogen components of the study were terminated early because of increased incidence of thromboembolism and nonfatal myocardial infarction. It should be noted that the test subjects were elderly males with a known history of coronary disease. No controls were established with regard to other cardiovascular treatment, especially aspirin use and cigarette smoking.