Table 4.

Role of adipokines in promoting risk factors of metabolic syndrome

Leptin suppress appetite and increase energy expenditure. Most obese persons have elevated leptin levels that do not suppress appetite. Leptin may elevate blood pressure and contribute to atherosclerosis and cardiovascular disease. Adiponectin has anti-atherogenic properties and improves insulin sensitivity. Its levels are decreased in obese subjects. Tumor necrosis factor-alpha and interleukin-6 may increase insulin resistance by preventing the auto-phosphorylation of the insulin receptor and suppressing second messenger signaling, through the inhibition of the enzyme tyrosinase kinase. Plaminogen activator inhibitor-1 prevents the dissolution of clots by inhibiting extracellular matrix degradation and fibrinolysis. It is thought to contribute to the development of type 2 diabetes and coronary thrombi. Angiotensinogen has vasoconstrictive effects on the blood vessels, and contributes to hypertension. Vascular endothelial growth factor plays a role in atherogenesis and hypertension.