Managing Cardiometabolic Risk

Exercise and Cardiometabolic Risk

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A joint statement by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) challenged the concept of the metabolic syndrome and questioned its clinical utility above and beyond individual risk factors (12). The statement also concluded that “the metabolic syndrome has been imprecisely defined, there is a lack of certainty regarding its pathogenesis, and there is considerable doubt regarding its value as a CVD risk marker” (12). Following the publication of the critical review of the metabolic syndrome, the International Chair on Cardiometabolic Risk (13), the ADA, and the American Heart Association (AHA) introduced the concept of global cardiometabolic risk, which goes beyond the earlier meaning of the metabolic syndrome to encompass a broader cluster of risk factors associated with CVD and type 2 diabetes (14). Cardiometabolic risk includes the features of the metabolic syndrome as well as traditional CVD risk factors (13). Among Canadian adults, physical inactivity is the most prevalent cause of abdominal obesity and the metabolic syndrome (15), and along with smoking is one of the factors that is easiest to target. In addition, physical activity and/or exercise have consistently been recommended for the reduction of many individual cardiometabolic risk factors (9) (10) (16). Prospective studies have shown that increasing physical activity seems to protect against the development of diabetes and CVD in a dose-response manner (17) (18). Exercise’s specific role in reducing abdominal obesity, intra-abdominal (visceral) fat in particular, and improving insulin sensitivity, lipid levels (triglycerides, HDL cholesterol, LDL size), blood pressure, thrombosis, and inflammation is examined below.

Although the terms physical activity and exercise are often used interchangeably, a distinction has been made between them for the purposes of this document. Physical activity is defined as any bodily movement produced by skeletal muscles resulting in increased energy expenditure. It includes both occupational and leisure-time physical activity. Exercise is a component of leisure-time physical activity that is planned, structured, repetitive, and performed for the purpose of improving or maintaining physical fitness. While the evidence presented here mainly addresses the effects of structured and regular exercise, it is well established that increasing physical activity during leisure and non-leisure time yields significant benefits (19).

Reference

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9. Executive Summary of The Third Report of The National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, And Treatment of High Blood Cholesterol In Adults (Adult Treatment Panel III). JAMA 2001; 285: 2486-97.

10. Grundy SM, Brewer HB, Jr., Cleeman JI, et al. Definition of metabolic syndrome: Report of the National Heart, Lung, and Blood Institute/American Heart Association conference on scientific issues related to definition. Circulation 2004; 109: 433-8.

12. Kahn R, Buse J, Ferrannini E, et al. The metabolic syndrome: time for a critical appraisal: joint statement from the American Diabetes Association and the European Association for the Study of Diabetes. Diabetes Care 2005; 28: 2289-304.

13. Després JP and Lemieux I. Abdominal obesity and metabolic syndrome. Nature 2006; 444: 881-7.

14. Eckel RH, Kahn R, Robertson RM, et al. Preventing cardiovascular disease and diabetes: a call to action from the American Diabetes Association and the American Heart Association. Diabetes Care 2006; 29: 1697-9.

15. Statistics Canada. Physical Activity, by age group and sex. 2005. http://www40.statcan.ca/l01/cst01/health46.htm, last accessed August 2007.

16. Grundy SM, Hansen B, Smith SC, Jr., et al. Clinical management of metabolic syndrome: report of the American Heart Association/National Heart, Lung, and Blood Institute/American Diabetes Association conference on scientific issues related to management. Circulation 2004; 109: 551-6.

17. Kohl HW, 3rd. Physical activity and cardiovascular disease: evidence for a dose response. Med Sci Sports Exerc 2001; 33: S472-83; discussion S93-4.

18. Kelley DE and Goodpaster BH. Effects of exercise on glucose homeostasis in Type 2 diabetes mellitus. Med Sci Sports Exerc 2001; 33: S495-501; discussion S28-9.

19. Physical activity and health. A report from the surgeon general executive summary. http://www.cdc.gov/nccdphp/sgr/pdf/execsumm.pdf. 1999.

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