Lifestyle changes are more effective than drug treatment in preventing metabolic syndrome, the cluster of disorders that can lead to diabetes and heart disease, according to a new study.

Dr. Trevor J. Orchard, at the University of Pittsburgh in Pennsylvania, and colleagues followed 3234 people who had not yet developed outright diabetes but who had high blood glucose levels.

The subjects were enrolled in the Diabetes Prevention Program, and were randomly assigned to take the anti-diabetes drug metformin, or an inactive placebo pill, or to undertake an intensive lifestyle intervention -- designed to achieve and maintain a 7 percent weight loss and 150 minutes of exercise per week.

As reported in the Annals of Internal Medicine, metabolic syndrome -- which is a combination of obesity, high cholesterol, high blood pressure and high blood sugar levels -- was diagnosed in 53 percent of the participants overall when they were enrolled in the study.

After an average 3-year follow-up, the rate of metabolic syndrome decreased from 51 percent to 43 percent in the lifestyle group. However, it increased from 55 percent to 61 percent in the placebo group, and from 54 percent to 55 percent in the metformin group.

These findings highlight the value of lifestyle interventions in the prevention and treatment of metabolic syndrome, Orchard's group notes.

The "dramatic" effect of lifestyle in preventing metabolic syndrome and reducing of its overall prevalence "appears to be most strongly related to a reduction in waist circumference and in blood pressure," rather than to improved cholesterol levels, the team also reports.

SOURCE: Annals of Internal Medicine, April 19, 2005.