Role of diabetes in influencing leptin concentration in elderly overweightpatients

Background: Leptin, the product of the ob gene, could have a significant ro le in the pathogenesis of obesity and non-insulin-dependent diabetes mellit us. However, it is still debated whether different degrees of glucose toler ance may affect plasma leptin concentrations in obese patients. Objective: To investigate whether diabetes might influence leptin concentra tions in obese patients. Methods: We evaluated clinical parameters, anthropometric measures, and sex hormones, fasting plasma leptin, glucose and insulin concentrations in 100 elderly obese diabetic patients and 100 obese non-diabetic control individ uals matched for age and sex. Results: After adjustment for age and fat mass, plasma leptin concentration s did not differ between diabetic and non-diabetic obese individuals, in bo th men and women. In all patients leptin was significantly related to body mass index, fat mass and the homeostasis model insulin resistance index: mo reover we observed a significant relationship with fasting plasma glucose a nd age in diabetic obese women, and with blood pressure values and testoste rone concentrations in diabetic obese men. Multiple regression analysis rev ealed age and fasting plasma glucose to be the only independent determinant s of fasting plasma leptin in diabetic obese women. Conclusions: These data suggest that leptin concentrations do not differ be tween obese diabetic and obese non-diabetic elderly patients. Among correla tes of the metabolic syndrome, systolic pressure seems to be related to lep tin only in men. In the postmenopausal or andropausal status, sex hormones are related to leptin concentrations only in diabetic men: in diabetic wome n, however, high glucose seems to be relevant in maintaining the same lepti n concentrations as in non-diabetic women with similar degree of obesity.