Drugs lower blood glucose without weight gain

NEW YORK (Reuters Health) - Two new antidiabetes drugs are modestly effective at reducing blood glucose levels without causing weight gain in people with type 2 diabetes, according to a review in this week's Journal of the American Medical Association.

Both drugs target incretin hormones that are produced in the gastrointestinal tract and boost the release of insulin triggered by glucose. This "incretin pathway" appears to be weakened in type 2 diabetes.

In 2005, the US Food and Drug Administration approved exenatide, which mimics the effect of the incretins, as add-on treatment for type 2 diabetes. The following year, the agency approved the incretin enhancer sitagliptin. Of the two, only sitagliptin is taken orally.

Dr. Anastassios Pittas and associates at the Tufts-New England Medical Center in Boston reviewed clinical trials comparing incretin-based drugs with inactive "placebo" treatment or other diabetes medications.

The drugs reduced A1c levels, a measure of long-term glucose control, by a little less than a percentage point more did placebo. Both types of medication were "noninferior" to other anti-diabetic drugs.

Episodes of excessively low glucose levels (that is, hypoglycemia) were rare with both types of drug.

The drugs either produced a slight weight loss or were "weight neutral."

Nevertheless, there were significant side effects, the researchers note. Exenatide-type agents were linked to nausea and vomiting during the first two months, and diarrhea was also common. Sitagliptin-type drugs did not cause any gastrointestinal side effects but were associated with sore throat, urinary tract infection, and headache.

The authors propose that people with mild diabetes who are at risk of hypoglycemia and in need of weight loss "may benefit from this new class" of glucose-lowering drugs.

SOURCE: Journal of the American Medical Association, July 11, 2007.