A combination of drugs that researchers hoped would delay progression to diabetes and/or heart disease in people with impaired glucose tolerance provided little benefit, researchers reported Sunday at an Atlanta meeting of the American College of Cardiology. The findings were the second disappointing diabetes-related study at the meeting. A major study of intensively lowering blood pressure and cholesterol levels also found little benefit from the drugs and a potential for harm.
The new study was a large international trial of patients with impaired glucose tolerance, a disorder that is generally a first step in the development of diabetes. The study, sponsored by the Swiss drug maker Novartis, involved two of the company's drugs, Diovan and Starlix. Diovan, known generically as valsartan, is a heart drug from the family known as angiotensin-converting enzyme (ACE) inhibitors. Some small studies have suggested that drugs in this family can delay progression to diabetes. Starlix, known generically as nateglinide, is a member of the sulfonylurea family of drugs that stimulate the pancreas to produce more insulin. Researchers had hoped that using it after meals would reduce the postprandial spike in blood sugar levels, thereby slowing the progression to full-blown diabetes.
They didn't work.
Dr. Robert M. Cailiff, of Duke University Medical Center, studied 9,306 pre-diabetic patients at 806 medical centers in 40 countries. Half of them were given either Diovan or a placebo and half were given either Starlix or a placebo. All the subjects were required to participate in a lifestyle-modification program with the goal of maintaining a 5% weight loss, following a low-fat diet and increasing exercise to an average of 30 minutes five times per week. The results were reported at the meeting and in two papers published online Sunday in the New England Journal of Medicine.
The team found that Diovan decreased progression to diabetes by about 14% over the five years of followup. About 33.1% of those in the Diovan group developed diabetes, compared with 36.8% of those in the placebo group. That's a much lower percentage of improvement than is shown with the older, cheaper drug metformin.
In contrast to the results with Diovan, about 36% of those in the Starlix group developed diabetes, compared with 34% in the placebo group. The risk of heart disease, heart attacks and death in 6 1/2 years of followup was not changed in the groups that took either drug or in a small group that took both.
In an editorial accompanying the papers, Dr. David Nathan, of Massachusetts General Hospital, wrote that the "prevention of diabetes remains a critical public health priority, but for now we should steer away from these two drugs and use effective lifestyle interventions" or metformin.
-- Thomas H. Maugh II