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

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 nondiabetic, obese women and in 51 normal-weight subjects, using immunoenzymatic assays. Results: Obese women had significantly higher levels of leptin, VWF, FVIIa, F1 + 2 compared with healthy women. Simple correlation coefficients showed significant correlation between leptin and either VWF, FVIIa, or F1 + 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 proatherogenic effects in vivo, with a mechanism involving endothelial cell activation.