Plasma endothelin-1 levels in non-insulin dependent diabetes mellitus patients with macrovascular disease

BACKGROUND: Endothelin-1 (ET-1) with its well-known vasoconstrictive and mitogenic action and through its interaction with insulin, blood glucose, and lipids might play an important role in the accelerated atherogenic process in diabetes mellitus. OBJECTIVE: To determine whether ET-1 levels are indicative of macrovascular disease in diabetes mellitus. METHODS: In the present cross-sectional study, plasma ET-1 concentrations were measured in members of three groups. The first group consisted of 20 patients (15 men and five women; aged 56.3 +/- 12.5 years) with non-insulin-dependent diabetes mellitus and coronary artery disease, the second group of 20 patients (16 men and four women, aged 56.9 +/- 11.2 years) with coronary artery disease only, and the third group of 10 healthy subjects who served as controls. ET-1 levels were determined by a radioimmunoassay. RESULTS: The mean plasma ET-1 levels for the three groups were 3.59 +/- 1.88, 4.31 +/- 1.32, and 4.42 +/- 1.01 pmol/l respectively, and there was no statistically significant difference among the groups (P = 0.23). There was also no correlation between the plasma ET-1 concentration and age, sex, body mass index, triglyceride, total cholesterol, high-, low- and very-low density lipoprotein levels, for all groups, and, for the first group, hemoglobin A1c (HbA1c), the duration of diabetes mellitus. CONCLUSION: The plasma ET-1 concentration is not elevated in non-insulin-dependent diabetes mellitus patients with macrovascular disease, which might reflect the fact that its action occurs in a paracrine or an autocrine rather than an endocrine fashion and suggests that ET-1 levels are not necessarily indicative of macrovascular disease in diabetes mellitus.