Endocrine Abstracts

Hyperleptinemia is associated with such risk factors for cardiovascular disease as insulin resistance, obesity and hypertension. Recently, it has been identified that leptin has prothrombotic properties and increases the accumulation of oxidant radicals in endothelial cells. It is hypothesized that leptin may be also one of the mediators promoting atherosclerosis.

The objectives of the work were to:

determine whether there are any connections between serum leptin and the presence and extent of coronary arteriosclerosis and such of cardiovascular risk factors as hypertension, diabetes, body mass and age.

The tests comprised 149 men with angiographically diagnosed coronary artery disease (CAD), mean age was 56, mean BMI 28. 38 men had 1-vessel disease, 35 men: 2-vessel disease and 76 men had diffuse changes in coronary angiograms. 92 men with CAD had recognised hypertension and 58 men had diabetes. The control group consisted of 14 healthy men without risk factors in which coronarography excluded atherosclerotic changes (mean age 48, mean BMI 26). Leptin concentrations were measured by RIA method. The studies were carried out with the permission of the local Bioethic Committee.

Results: Serum levels of leptin were significantly higher in the group with CAD(p<0,01). We found significant correlation between leptin and BMI (p<0,001) and cholesterol concentration (p<0,001). No correlations emerged between leptin concentrations and age. Leptin levels were compared in cases with 1- and 2- and 3-vessel disease, showing no differences associated with increasing severity of CAD. Men with CAD and hypertension and diabetes had a significantly higher leptin concentration (9,6 ng/ml) compared with the patients with CAD and hypertension/or diabetes (8,7 ng/ml), independent of BMI. The lowest concentration (6,3 ng/ml) we observed in men with CAD but without hypertension and without diabetes.

Conclusions: Leptin probably is one of the many factors which are involved in the pathogenesis of complications of obesity as atherosclerosis, hypertension and diabetes.

Leptin does not directly affect the severity of changes in coronary arteries in men.