Michelle Rizzo, New York: Unlike earlier beta-blocker drugs used to treat high blood pressure, the newer drug carvedilol does not cause weight gain in people with diabetes, according to findings from a new study.

"Increases in body weight have been documented with long-term therapy of traditional beta-blockers," Dr. Franz H.Messerli, of St. Luke's-Roosevelt Hospital Center, New York, and colleagues write in the American Journal of Medicine.

"Anyweight gain is of concern in patients with type 2 diabetes because of the rise in insulin resistance associated with excess weight and obesity. "The researchers evaluated the effects of carvedilol as compared to the older beta-blocker metoprolol on weight gain in about 1100 patients with type 2 diabetes and high blood pressure.

Changes in body weight were tracked from the beginning of treatment over 5 months. On average, participants taking metoprolol gained 1.19 kg after 5 months, whereas there was a small and insignificant average gain of 0.17 kg among those given carvedilol.

A gain of at least 7 percent in body weight occurred in 4.5 percent of metoprolol-treated patients but in only 1.1 percent of those treated with carvedilol, the team reports.

The results "would indicate that with regard to weight gain...not all beta-blockers are created equal," Messerli told Reuters Health. He advised doctors "to avoid traditional beta-blockers such as atenolol and metoprolol in the diabetic hypertensive patient or in the hypertensive patient at risk for diabetes, and to use a beta-blocker such as carvedilol that has no detrimental effects."