PAI-1 is a cytokine responsible for much of the prothrombotic state associated with metabolic syndrome. PAI-1 regulates the formation of thrombi by promoting formation of thrombin, platelet aggregation, and fibrin. PAI-1 inhibits fibrinolysis by blocking the activity of tissue-type plasminogen activator. PAI-1 is synthesized and released from the liver and adipocytes.
PAI-1 is increased in obesity, is associated with insulin resistance, and is an early inflammatory predictor of type 2 diabetes.