title: The deadly quartet--the insulin resistance syndrome.
abstract: BACKGROUND
  Obesity, non-insulin-dependent diabetes mellitus, hypertension, and dyslipidemia (syndrome X, "the deadly quartet") are common metabolic disorders that predispose to early cardiovascular disease. We examine the relationship between insulin resistance and the deadly quartet and address therapeutic implications.
  
  
  METHODS
  We review the literature on insulin resistance, using MEDLINE files from 1975 to the present. Fifty references were reviewed.
  
  
  RESULTS
  Insulin resistance consists of a cluster of disorders and biochemical abnormalities. We discuss the mechanisms responsible for the defects in insulin-mediated glucose utilization, as well as the relation of insulin resistance to obesity, hypertension, and dyslipidemia. We review the current strategies used in light of this pathophysiologic approach.
  
  
  CONCLUSIONS
  This extremely common syndrome contributes excessively to mortality and morbidity of millions of Americans and generates enormous costs to the health care system. Better molecular understanding of insulin resistance is leading to improved treatment of all components of the syndrome.
authors.affiliation: Department of Family and Preventive Medicine, Meharry Medical College, Nashville, Tenn, USA.
authors.forename: J U
authors.initials: JU
authors.lastname: Opara
authors.forename: J H
authors.initials: JH
authors.lastname: Levine
mesh_terms: D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy / Q000503:physiopathology*; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D007333:Insulin Resistance / Q000502:physiology; D009765:Obesity / Q000503:physiopathology*; D013577:Syndrome