Leptin increase is associated with markers of the hemostatic system in obese healthy women

Summary.  Background : Leptin, a hormone secreted by the adipose tissue, might be a link between obesity and increased morbidity for cardiovascular disease. Leptin exerts proinflammatory, pro-angiogenic actions by activating a specific receptor (Ob-Rb) which is expressed in human endothelial cells. Thus, a link may exist between leptin expression and endothelial dysfunction. Objectives : We sought to determine whether in obese women there is a correlation between leptin levels, endothelial perturbation and coagulative activation. Methods : Circulating levels of leptin, von Willebrand Factor (VWF), factor (F)VIIa, prothrombin fragment 1 + 2 (F1+2), were measured in 51 non-diabetic, obese women and in 51 normal-weight subjects, using immunoenzymatic assays. Results : Obese women had significantly higher levels of leptin, VWF, FVIIa, F 1+2 compared with healthy women. Simple correlation coefficients showed significant correlation between leptin and either VWF, FVIIa, or F 1+2 concentrations. A multiple linear regression analysis, performed to quantify further the relationship between leptin levels and the above-mentioned variables as well as the inflammatory marker C-reactive protein (CRP) and including age, body mass index (BMI), waist–hip ratio (WHR) and lipid parameters as potential confounders, revealed that only FVIIa and VWF were independently related to leptin levels. Reduction in adipose tissue after weight loss resulted in a decrease in both circulating leptin and endothelial and coagulative activation markers. Conclusions : We suggest that leptin might have pro-atherogenic effects in vivo , with a mechanism involving endothelial cell activation.