Metabolic syndrome occurs in about 25% of the adult population in industrialised countries. The pathogenesis of this syndrome is associated with insulin resistance. There are growing evidence that proteins produced in adipose tissue can play a role in development of insulin resistance. One of them is adiponectin (APM1), that circulates in human plasma at high level (5-30 microg/ml). A reduction in APM1 expression is closely associated with insulin resistance in animal models and in studies in humans. APM1 correlates with typical features of metabolic syndrome: BMI, WHR, total cholesterol, HDL, LDL and triglyceride levels, glucose, insulin, degree of insulin resistance in hyperinsulinemic-euglycemic clamp, blood pressure, hyperuricemia. There are some hypotheses that in the future therapy with APM1 may play a role in reversing insulin resistance in many disorders.