The drug Actos (pioglitazone), designed to reduce insulin resistance in type 2 diabetics, also appears to slow the thickening of artery walls, a process that increases the risk of heart attacks and strokes, according to University of Illinois at Chicago researchers.

Their study, presented at the American Heart Association annual meeting, involved 462 adults in the Chicago area who received either Actos or an older diabetes drug, Amaryl (glimepiride).

Over the course of 18 months, researchers used ultrasound to measure the thickness of the inner lining of the carotid artery of participants in the study. Those taking Actos actually had a slight regression of inner wall carotid thickness while those on glimepiride had an increase.

Those on Actos also had a 13 percent increase in HDL (good) cholesterol compared with a 1 percent drop in glimepiride users. Actos users also had a 13 percent drop in triglycerides, a type of unhealthy fat found in the blood, compared with a 2 percent increase in those on glimepiride.

"The importance of our study rests on the relationship between diabetes and heart attack and stroke," said Dr. Theodore Mazzone, of the University of Illinois at Chicago.

"Heart disease kills 80 percent of people with diabetes," said Mazzone. "If you prevent heart disease in those patients, it's a big advance."

However, the researchers noted that concerns remain about side effects of the drug and cautioned that more research is needed.

Actos is in a class of drugs called thiazolidinediones, which lower the amount of blood sugar glucose released by the liver and make cells more sensitive to insulin. Mazzone said it was unclear whether the other major medication in the class, Avandia, would have the same effect on artery wall thickness as Actos.