Oestradiol levels in diabetic men with and without a previous myocardial infarction.

Elevated oestradiol levels have been found in men with a previous myocardial infarction and it has been suggested that hyperoestrogenaemia may explain partly the increased risk of coronary heart disease in diabetes mellitus. Therefore we have measured concentrations of oestradiol and testosterone (the main substrate for oestradiol) in a group of diabetic men with a previous myocardial infarction (n = 15), a matched group of diabetic men without overt cardiovascular disease (n = 13) and a group of healthy, non-diabetic men (n = 15). The diabetics had elevated oestradiol levels (p less than 0.03) despite lower testosterone levels (p less than 0.02) compared with control subjects. In the diabetic patients, a correlation between oestradiol and testosterone was found (r = 0.55, p less than 0.02) which suggested that the elevated oestradiol levels were only partly derived from the aromatization of testosterone. There were no differences in oestradiol or testosterone levels between the two diabetic groups. This study has shown that endogenous hyperoestrogenaemia is a consistent finding in diabetic men, irrespective of whether they have or have not sustained a previous myocardial infarction. The source of the raised oestradiol levels is uncertain. It is unclear whether hyperoestrogenaemia can be regarded as a risk for myocardial infarction in diabetic men.