Plasma adiponectin concentration in relation to severity of coronary atherosclerosis and cardiovascular risk factors in middle-aged men

Adiponectin, an adipocyte-derived protein, seems to be a link between obesity, insulin resistance, and atherosclerosis. The present study investigated the association between adiponectin and coronary artery disease in middle-aged men. Material and methods: We examined 48 men (aged 40-60) with angiographically confirmed coronary atherosclerosis and 19 healthy men, matched by age, as a control group. Concentrations of glucose and lipids were estimated with enzymatic methods. Plasma level of adiponectin, total and free testosterone, estradiol, estrone, DHEA-S, and insulin were estimated with RIA commercial kits. Results: Men with coronary atherosclerosis had lower plasma adiponectin level than controls (16.2 +/- 9.2 +/- 20.5 6.7 mu g/mL; p < 0.05). However, after including BMI and waist as covariate data in ANCOVA, the difference in adiponectin levels between men with CAD and controls lost statistical significance (respectively for BMI and waist: p = 0.4 and p = 0.7). Moreover, although not significant, adiponectin levels decreased as a function of the number of significantly narrowed coronary arteries. In a priori comparison the lowest adiponectin plasma concentration was in men with three-vessel coronary artery disease (14.3 +/- 9.8 mu g/mL) and the highest in controls (20.5 +/- 6.8 mu g/mL; p = 0.09). Adiponectin plasma level correlated negatively (p < 0.05) with BMI, waist, percentage of total fat, fasting-insulin-resistance index (FIRI), total cholesterol and triglycerides, and positively with quantitative insulin sensitivity check index (QUICKI), HDL cholesterol, total testosterone, and total testosterone/estradiol ratio. Conclusions: Our data suggest that low plasma adiponectin level is connected with insulin resistance syndrome and atherogenic lipid profile. It seems that adiponectin plays a role in pathogenesis of coronary atherosclerosis, especially in obese and insulin-resistant subjects.