Characteristics of US adults with the metabolic syndrome and therapeutic implications

Background: The third Adult Treatment Panel (ATP III) of the National Cholesterol Education Program defines clinical criteria for diagnosis of the metabolic syndrome, which increases cardiovascular risk and is a target for therapy. Aim: We analysed the third National Health and Nutrition Examination Survey (NHANES III; 1988-94) to determine how many US adults meet these criteria and are recommended for lipid-modifying drug therapy by ATP III. Methods: NHANES III data were used to estimate the number of individuals with the metabolic syndrome and the number recommended for treatment by ATP III, based on 1990 census data. Results: An estimated 36.3 million (23%) US adults have the metabolic syndrome. Of these, 84% met the criterion for obesity, 76% for blood pressure, 75% for HDL-C, 74% for triglycerides and 41% for glucose. Most (54%) are in the higher risk categories of ATP III, yet only 39% overall are recommended for drug therapy by ATP III cutpoints; of these, most will achieve LDL-C targets with reductions of 35-40%. Of the 15.3 million individuals with the metabolic syndrome and triglycerides greater than or equal to2.26 mmol/l (200 mg/dl), non-HDL-C is above ATP 111 recommendations in 11.6 million. Conclusions: Of the large number of Americans with the metabolic syndrome, ATP III recommends drug therapy for only a minority, because LDL-C typically is not substantially elevated. Instead, high triglycerides and low HDL-C are more common; clinical trial data are needed to determine whether optimal therapy should focus on reductions in LDL-C or on comprehensive improvements to the lipid profile.