THE DEADLY QUARTET - THE INSULIN-RESISTANCE SYNDROME

Background. Obesity, non-insulin-dependent diabetes mellitus, hyperten sion, and dyslipidemia (syndrome X, ''the deadly quartet'') are common metabolic disorders that predispose to early cardiovascular disease. We examine relationship between insulin resistance and the deadly quar tet and address therapeutic implications. Methods. We review the liter ature on insulin resistance,using MEDLINE files from 1975 to the prese nt. Fifty references were reviewed. Results. Insulin resistance consis ts of a cluster of disorders and biochemical abnormalities. We discuss the mechanisms responsible for the defects in insulin-mediated glucos e utilization,as well as the relation of insulin resistance to obesity , hypertension, and dyslipidemia. We review the current strategies use d in light of this pathophysiologic approach. Conclusions. This extrem ely common syndrome contributes excessively to mortality and morbidity of millions of Americans and generates enormous costs to the health c are system. Better molecular understanding of insulin resistance is le ading to improved treatment of all components of the syndrome.