Toward an Improved Diagnosis of the Metabolic SyndromeOther Clues to the Presence of Insulin Resistance

A substantial portion of the population of the United States has the Metabolic Syndrome, a condition that greatly increases risk for cardiovascular disease and diabetes. Insulin resistance, and the resulting compensatory hyperinsulinemia, is the principal pathophysiologic abnormality underlying the majority of these cases. Based on the most recent recommendations of the National Cholesterol Education Panel, such patients can be identified by the presence of three or more of the following traits: impaired fasting glucose, abdominal obesity, hypertension, elevated levels of triglycerides, and low concentrations of HDL-cholesterol. However, a significant number of insulin resistant (and thus high risk) individuals will not be identified using these criteria. This discrepancy occurs because insulin resistance is a continuous variable, without an absolute cut-off between normal and abnormal, and those fitting the definition are the most insulin resistant. Moreover, easily applicable testing to diagnose insulin resistance accurately in the general population is currently not feasible. It is therefore necessary to broaden the criteria that define the metabolic syndrome to include other conditions associated with the presence of insulin resistance. Such conditions include the following: a family history of type 2 diabetes or coronary artery disease in first- or second-degree relatives, signs of an over active sympathetic nervous system, and elevated concentrations of uric acid. By recognizing these "other conditions," appropriate lifestyle changes and medication can be recommended to help prevent cardiovascular disease and diabetes from developing in these high-risk patients.