Drugs Delay Progression to Diabetes

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Glycemic durability of rosiglitazone, metformin, or glyburide monotherapy, by S.E. Kahn and colleagues. N Engl J Med 355:2427–2443, 2006.

What is the problem and what is known about it so far?

When a person’s body handles glucose and insulin poorly, drug treatment can delay the development of diabetes. Doctors have several types of drugs to choose from, but little is known about whether one type has advantages or benefits over the others.

Why did the researchers do this particular study?

The researchers wanted to test three drugs often chosen for first-time treatment of people with diabetes: metformin (Glucophage, Bristol-Myers Squibb), rosiglitazone (Avandia, GlaxoSmithKline), and glyburide (Micronase, Pfizer). The goal was to compare rosiglitazone to the two older drugs in their ability to control blood glucose levels.

Who was studied?

The study included 4,300 people who were recently diagnosed with diabetes and had not been prescribed any other drug therapy for it.

How was the study done?

Participants were randomly chosen to receive metformin, rosiglitazone, or glyburide. The pills looked identical, and dosages were adjusted until they were most effective. Participants were followed for four years.

What did the researchers find?

Rosiglitazone delayed a worsening of blood glucose control or diabetes longer than the other drugs, but is more expensive than the others and increased the likelihood of weight gain and heart problems.

At the study period’s end, 15% of those taking rosiglitazone needed a second drug to control blood glucose, as compared to 21% of those taking metformin and 32% of those taking glyburide.

What were the limitations of the study?

The study was not designed to see whether there are differences in heart problems among people who took the three different drugs. If heart problems were more or less common with one particular drug, that information could affect a doctor’s decision.

A fairly large number of participants didn’t finish the study, which could have affected the results.

What are the implications of the study?

Rosiglitazone appears to delay the development of diabetes, but the drug’s value must be weighed against other considerations.