KATZMARZYK, P. T., A. S. LEON, J. H. WILMORE, J. S. SKINNER, D. C. RAO, T. RANKINEN, and C. BOUCHARD. Targeting the Metabolic Syndrome with Exercise: Evidence from the HERITAGE Family Study. Med. Sci. Sports Exerc., Vol. 35, No. 10, pp. 1703–1709, 2003.
Purpose: To determine the efficacy of exercise training in treating the metabolic syndrome.
Methods: The sample included 621 black and white participants from the HERITAGE Family Study, identified as sedentary and apparently healthy (no chronic disease or injury). The metabolic syndrome was defined as having three or more risk factors according to the guidelines of the National Cholesterol Education Program, including elevated waist circumference, blood pressure, triglycerides, blood glucose, and low HDL cholesterol. The presence of the metabolic syndrome and component risk factors were determined before and after 20 wk of supervised aerobic exercise training.
Results: The prevalence of the metabolic syndrome was 16.9% in this sample (105/621) of apparently healthy participants. Of the 105 participants with the metabolic syndrome at baseline, 30.5% (32 participants) were no longer classified as having the metabolic syndrome after the exercise training. Among the 32 participants who improved their metabolic profile, 43% decreased triglycerides, 16% improved HDL cholesterol, 38% decreased blood pressure, 9% improved fasting plasma glucose, and 28% decreased their waist circumference. There were no sex or race differences in the efficacy of exercise in treating the metabolic syndrome: 32.7% of men, 28.0% of women, 29.7% of black, and 30.9% of white participants with the metabolic syndrome were no longer classified as having the syndrome after training.
Conclusion: Aerobic exercise training in patients with the metabolic syndrome can be useful as a treatment strategy and provides support for a role for physical activity in the prevention of chronic disease.
A major new feature of the U.S. National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III) recommendations for the reduction of high blood cholesterol is the emphasis on aggressively targeting individuals with multiple risk factors for treatment due to their substantially increased risk for coronary artery disease (27). Indeed, results from the Multiple Risk Factor Intervention Trial (MRFIT) indicate that the risk of cardiovascular disease mortality increases with the number of risk factors that a person has (1). The metabolic syndrome is a constellation of multiple hypertension, dyslipidemia, and diabetes risk factors that cluster together and increase the risk of Type 2 diabetes, coronary artery disease, and premature mortality. According to the operational definition provided by the NCEP ATP III, an individual has the metabolic syndrome if three or more of high blood pressure, high blood glucose, high plasma triglycerides, low HDL cholesterol, and high waist circumference are present (27). The metabolic syndrome is a prevalent condition in North America, as recent estimates indicate that 24% and 23% of U.S. men and women, respectively (8), and 17% and 13% of Canadian men and women, respectively (2), have the metabolic syndrome as recently defined by the NCEP ATP III (27). Thus, there is a need to develop efficacious and effective lifestyle strategies to combat the metabolic syndrome and its associated health risks.
Current recommendations for the treatment of the metabolic syndrome and the primary prevention of cardiovascular diseases encourage the use of therapeutic lifestyle changes such as increasing physical activity and reducing the dietary intake of saturated fat and cholesterol (21,27). Physical activity interventions, in the form of exercise training programs, have been shown to reduce individual heart disease risk factors such as high blood pressure (7), high plasma triglycerides (6), high blood glucose (14), and low HDL cholesterol (6,19). However, little is known about the effects of exercise training on the reduction of several risk factors simultaneously in individuals already at a high risk for metabolic diseases. Thus, the purpose of this study was to determine the efficacy of aerobic exercise training for treating the metabolic syndrome in participants in the HERITAGE Family Study.