Summary points

• Insulin resistance is a state in which normal concentrations of insulin produce a subnormal biological response

• Patients with insulin resistance have hyperinsulinaemia together with normoglycaemia or hyperglycaemia

• Insulin resistance is commonly associated with obesity, non-insulin dependent diabetes mellitus, and essential hypertension

• The insulin resistance syndrome includes impaired insulin stimulated glucose uptake, hyperinsulinaemia, glucose intolerance, hypertension, and dyslipidaemia

• Drugs such as corticosteroids, ß blockers, and high dose thiazides can exacerbate insulin resistance; angiotensin converting enzyme inhibitors and (alpha) blockers may reduce resistance

• Reducing insulin resistance is important in managing non-insulin dependent diabetes—for example, by losing weight, aerobic exercise, and stopping smoking; moderate alcohol consumption improves insulin resistance

• Metformin improves multiple aspects of the insulin resistance syndrome. Novel insulin action enhancing drugs including the thiazolidinediones are under evaluation