The multifaceted role of natriuretic peptides in metabolic syndrome.

Due to globalization and sophisticated western and sedentary lifestyle, metabolic syndrome has emerged as a serious public health challenge. Obesity is significantly increasing worldwide because of increased high calorie food intake and decreased physical activity leading to hypertension, dyslipidemia, atherosclerosis, and insulin resistance. Thus, metabolic syndrome constitutes cardiovascular disease, type 2 diabetes, obesity, and nonalcoholic fatty liver disease (NAFLD) and recently some cancers are also considered to be associated with this syndrome. There is increasing evidence of the involvement of natriuretic peptides (NP) in the pathophysiology of metabolic diseases. The natriuretic peptides are cardiac hormones, which are produced in the cardiac atrium, ventricles of the heart and the endothelium. These peptides are involved in the homeostatic control of body water, sodium intake, potassium transport, lipolysis in adipocytes and regulates blood pressure. The three known natriuretic peptide hormones present in the natriuretic system are atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and c-type natriuretic peptide (CNP). These three peptides primarily function as endogenous ligands and mainly act via their membrane receptors such as natriuretic peptide receptor A (NPR-A), natriuretic peptide receptor B (NPR-B) and natriuretic peptide receptor C (NPR-C) and regulate various physiological and metabolic functions. This review will shed light on the structure and function of natriuretic peptides and their receptors and their role in the metabolic syndrome.