Physical Activity and Cardiovascular Risk in Diabetic Women

IN RESPONSE:

Dr. Kessler questions the clinical implications of our study (1) and raises the issue of benefits compared with costs of physical activity. He has raised similar issues regarding our previous reports (2, 3). Despite his intricate calculations, Dr. Kessler misses the point of our study. First, although it may take several years of activity to prevent a single cardiovascular event among the least active group as a whole, for each individual woman, only 30 minutes to 1 hour of moderate to vigorous exercise per day is needed. Second, Dr. Kessler considers only the lowest and highest risk groups and ignores women in the middle categories. As we showed, the inverse association between physical activity and risk for cardiovascular disease is approximately linear, and women in the middle categories (<1 hour of exercise per week) also benefit substantially from exercise. Third, exercise has numerous other benefits, such as reducing blood pressure, increasing levels of high-density lipoprotein cholesterol, maintaining healthy weight, preventing osteoporosis, reducing risk for some types of cancer, and improving quality of life (4). Exercise is one of the most cost-effective ways to reduce morbidity and mortality. Unfortunately, most of the U.S. population is sedentary.