Role of leptin in the cardiovascular and endocrine complications of metabolic syndrome

Aim: To review the potential role of leptin, hyperleptinaemia and leptin resistance in the cardiovascular and endocrine complications of metabolic syndrome. Methods: Review of literature listed in Medline. Results: Hyperleptinaemia is common in obesity and reflects increased adiposity and leptin resistance. Nevertheless, leptin resistance may not be complete as several actions of leptin, such as cardiovascular sympatho-activation, might be preserved in obese subjects known to be resistant to the metabolic effects of leptin (i.e. selective leptin resistance). Notably, the renal and sympathetic actions of leptin may play an important role in the pathogenesis of hypertension related to obesity and metabolic syndrome. Furthermore, the lipotoxic effect of leptin resistance may cause insulin resistance and beta cell dysfunction, increasing the risk of type 2 diabetes. Leptin has also been shown to possess proliferative, pro-inflammatory, pro-thrombotic, and pro-oxidative actions. Conclusion: Hyperleptinaemia and leptin resistance may contribute to hypertension, impaired glucose metabolism, and pro-atherogenic state in obesity and metabolic syndrome.