Effects of exercise and weight loss on cardiac risk factors associated with syndrome X

Patients with high blood pressure (BP) often exhibit syndrome X, an aggregation of abnormalities in carbohydrate and lipoprotein metabolism associated with increased risk of coronary heart disease (CHD). The present study evaluated the effects of a 6-month intervention involving either aerobic exercise training alone (EX only) or exercise combined with a structured weight loss program (EX + WL) on CHD risk factors associated with syndrome X.

A total of 53 men and women were selected from a larger behavioral intervention trial, who showed the hyperinsulinemia, dyslipidemia, and high BP characteristic of syndrome X. Participants were randomly assigned to EX only (n = 21), EX + WL (n = 21), or a waiting list control group (n = 11). Before and following treatment, participants underwent measurement of glucose tolerance, lipid levels, and clinical BP.

Hyperinsulinemic responses to glucose challenge were significantly reduced in both the EX + WL group (P<.001) and the EX-only group (P =.003). Participants who showed the largest amount of weight loss showed the most robust improvements in abnormal insulin responses (EX + WL group, 47% reduction; EX-only group, 27% reduction). Diastolic BP was significantly reduced in the EX + WL group (96 +/- 4 to 87 +/- 5 mm Hg [mean +/- SD]; P =.01), but not in the EX-only group (93 +/- 4 to 89 +/- 5 mm Hg [mean +/- SD]; P =.08). Lipid profile was not significantly improved by either intervention.

These results suggest that EX + WL is an effective treatment for hyperinsulinemia and lowering of diastolic BP in patients with the syndrome X.