WASHINGTON -- Staying active increases the chances that a person with diabetes will stay alive, a study finds.
This is the first study to find a lower risk of death from any cause among those who report being physically active, researchers say. Previous research has found that exercisers have a lower risk of developing diabetes. And, among people who have diabetes, exercise controls conditions from weight gain to cardiovascular disease that are common outgrowths of the disease.
"The bottom line is, you survive longer," said Dr. Ming Wei of the Cooper Institute for Aerobics Research in Dallas, lead author of the paper in Annals of Internal Medicine.
The researchers studied 1,263 men with type 2 diabetes, which accounts for at least 90 percent of all diabetes cases in the United States. In Type 2 diabetes, the body's cells become resistant to insulin, the hormone that regulates blood sugar levels and helps the sugars enter cells, where they can be used for energy.
The men in the study were given a thorough physical examination, including an exercise test. Based on the results, their fitness levels were ranked. Over an average of 12 years of followup, the men also responded to questionnaires about their physical activity, including walking, jogging or taking part in aerobic exercise programs.
Over the study period, 180 men died.
Men in the low-fit group in the exam were 2.1 times more likely than high-fit men to die from any cause, including heart disease, a major cause of death among diabetics. But the overall risk of death shrank as the level of fitness rose, so moderately fit men were better off than unfit ones, Wei said.
Men who reported in questionnaires that they were physically inactive had a 70 percent greater chance of dying than did men who reported being physically active. But self-reports are not highly accurate, so researchers did not detail any changes in risk based on the amount of activity that the men reported.
The findings give doctors a new reason to recommend exercise to diabetic patients, the report said. "Our data suggest that the beneficial effect of physical activity for patients with type 2 diabetes extends beyond its effect on intermediate risk factors" such as weight control, it said.
The researchers did not determine what type of exercise would be best. But Wei suspected diabetics could get the risk-reduction job done simply by following the guidelines that the federal government sets out for most Americans -- a minimum of 30 minutes of moderate activity, such as a brisk walk, on most days. He cautioned that diabetics should see their doctors before starting an exercise program.
The findings drew support from experts who did not work on the paper.
"This is exciting information," said Dr. Bruce R. Zimmerman, president of the American Diabetes Association. "I hope it will have an influence on many physicians who don't normally deal with those issues."
The paper had some weaknesses -- for instance, diabetics who took insulin were not in the study -- but the findings nonetheless are compelling, said Zimmerman, an endocrinologist at the Mayo Clinic, Rochester, Minn.
Another doctor urged physicians to stop waiting for more research, and to get on with encouraging patients to exercise. "General admonishments to get more exercise are as unlikely to work as general advice to eat less or stop smoking," Dr. Charles M. Clark Jr. of the Richard Roudebush VA Medical Center in Indianapolis wrote, in an editorial in the internal medicine journal. "Specific programs need to be prescribed, and follow-up is essential."
On the Net:
American College of Physicians-American Society of Medicine, which has the journal article online: http://www.acponline.org
American Diabetes Association: http://www.diabetes.org/