Insulin levels in insulin resistance: Phantom of the metabolic opera?

• Insulin resistance is considered a core component in the pathophysiology of the metabolic syndrome. • Some clinicians measure serum insulin concentrations in the mistaken belief that they can be used to diagnose insulin resistance. • Serum insulin levels are poor measures of insulin resistance. Furthermore, there is no clinical benefit in measuring insulin resistance in clinical practice. • Measurements of fasting serum insulin levels should be reserved for large population-based epidemiological studies, where they can provide valuable data on the relationship of insulin sensitivity to risk factors for diabetes and cardiovascular disease. • Clinicians should shift from identifying "insulin resistance" to identifying riskfactors, such as fasting glucose and lipid levels, hypertension and central obesity. These proven risk factors converge within the metabolic syndrome. • Individuals "at risk" of diabetes and atherosclerotic cardiac disease can be identified simply and inexpensively, using classic clinical techniques, such as history-taking, physical examination, and very basic investigations.