Circulating endothelin-1 levels in obese patients with the metabolic syndrome

We evaluated venous plasma ET-1 concentrations in 18 never-treated obese men (body mass index 31.0+/-0.5 kg/m(2); age 45.4+/-4.3 years) showing the whole features of the above syndrome and 12 control men (age 44.1+/-3.6 years). Circulating ET-1 levels were significantly higher in patients than in controls (p<0.05), and were directly correlated with fasting insulin levels (r=0.564, p=0.015) and erythrocyte Na+/Li+ counter-transport activity (r=0.504, p=0.033). In conclusion, venous plasma ET-1 levels are elevated in obese men manifesting the whole features of the metabolic syndrome. Due to the biological properties of ET-1, our findings suggest the peptide as a further component of the cluster of cardiovascular risk factors which characterizes this syndrome.