Inactivity better than BMI at flagging heart risk.(Clinical Rounds)

Physical inactivity and high body mass index are not necessarily equivalent in terms of predicting disease risk in women, according to findings from two studies.

Inactivity predicted increased heart disease risk in women with suspected ischemia more accurately than either body mass index or abdominal fat, but BMI was a stronger predictor of type 2 diabetes than was inactivity, according to data from the studies, both of which evaluated adult women participating in ongoing studies.

Being overweight is clearly a risk factor for cardiovascular disease, but studies on the role of exercise have been limited, especially in women with possible coronary artery disease and heart problems, said Dr. Timothy R. Wessel of the University of Florida, Gainesville, and his associates.

Of 908 women participating in the ongoing Women's Ischemia Syndrome Evaluation (WISE), 70% had low physical activity levels, 76% were overweight, and 41% were obese. The women (mean age 58 years) had been referred for coronary angiography. No significant differences in baseline angiograms were evident when women in higher BMI categories were compared.

Dr. Wessel and his colleagues evaluated physical fitness using the Duke Activity Status Index (DASI), a self-report questionnaire that assesses participants' abilities to perform various activities.

Regardless of their BMI category, women who were the least active (a DASI score of less than 25) had the highest risk of adverse events, including death from any cause or hospitalization for nonfatal MI, stroke, congestive heart failure, and unstable angina, during a mean follow-up of 4 years.

The incidence of adverse events in women with a BMI less than 30 kg/[m.sup.2], for example, was significantly lower in those with a DASI score of at least 25 (24%) than in those with a DASI score of less than 25 (43%). BMI did not predict all adverse events, major adverse events, or all-cause mortality (JAMA 292[10]:1179-87, 2004).