Drugs commonly prescribed for high blood pressure and heart disease may lower mortality rates in people with diabetes, even if they show no signs of heart or blood pressure problems.

Writing in the journal Diabetes Care, a team of researchers said that in a study over five years of almost 5,000 patients with diabetes, they found significant benefits for those taking the drugs, called ACE inhibitors.

The researchers, led by Jeffrey Johnson of the University of Alberta in Canada, reported that in the period of the study, there was a 51 percent reduction in deaths from all causes among the 1,187 patients taking the medication. There was a 23 percent reduction in deaths related to cardiovascular disease. The study estimated that for every 12 of the diabetics in the study given ACE inhibitors, after about four years, one death was prevented.

The study looked at Type 2 diabetes, which generally affects adults. The average age of the subjects was 60.

Many doctors already prescribe ACE inhibitors to patients with diabetes. But until now, the study said, there was only limited evidence to support benefits of the practice.

ACE inhibitors help blood vessels relax, allowing more oxygen to make it to the heart. They may also block an enzyme that appears to help bring about cardiovascular disease, which is the leading cause of death for diabetics, the American Diabetes Association says. Diabetics are more than twice as likely to die of heart disease as people without diabetes.