Type 2 Diabetes Is Preventable

From the WebMD Archives

May 2, 2001 -- Diabetes is nothing to fool with. If you're at high risk for it -- that is, if you are a bit overweight, a couch potato, and have a family history of diabetes -- you risk a lifetime of serious complications. What's more, you may end up taking medications such as insulin for the rest of your life.

But a new study adds proof to what doctors have been advising all along: eat right and get a little exercise, and you can stave off the disease.

You can find out more about preventing diabetes, or managing it if you have it, at WebMD's Diabetes chat board moderated by Gloria Yee, RN, CDE.

"This study provides evidence that type 2 diabetescan be prevented by changes in the lifestyles of both men and women at high risk for the disease," writes study author Jaakko Tuomilehto, MD, PhD, a researcher in the Diabetes and Genetic Epidemiology Unit of the University of Helsinki in Finland. His study appears in the current issue of The New England Journal of Medicine.

"This is an extremely important study," P. Antonio Tataranni, MD, a senior scientist with the NIH's National Institute of Diabetes, Digestive and Kidney Diseases, tells WebMD. "Doctors are always struggling with trying to convince patients that embracing a healthy lifestyle is a good thing to do. Now the data are there to show that that these changes will have a significant impact on the life of people who are at risk of diabetes." Tataranni was co-author of an editorial on the study.

Risk of diabetes is not to be taken lightly, says Lee J. Sanders, DPM, president of healthcare and education for the American Diabetes Association. "People with diabetes have a two- to fourfold increase for cardiovascular events like heart attacks and strokes," he tells WebMD. "Diabetes causes nerve damage throughout the body, making it the leading cause of blindness and lower extremity amputations. It is also the leading cause of end-stage renal failure. The long-term complications are very serious."

In their six-year study, Tuomilehto and colleagues enrolled 523 people who were at high risk of diabetes because they were overweight, between the ages of 40 and 65, and had a family history of diabetes. Each had taken a glucose tolerance test that showed that their glucose tolerance was impaired, evidence they were at an intermediate stage in terms of their risk of developing the disease. The patients were split into two groups.


Those in the comparison group were told that by changing dietary and exercise habits, they could reduce their risk of diabetes. They were given a two-page leaflet of nutritional suggestions, kept a three-day food diary at the beginning of the study and reported -- on each annual visit -- their nutrition habits.

The "intervention group" got considerably more attention: people were given detailed advice about how to achieve their goals -- how to reduce weight, total intake of fat, intake of saturated fat, increase in fiber. Each had seven sessions with a nutritionist during the first year and one session every three months afterwards. They were also coached to increase exercise to 30 minutes each day, mostly through "endurance exercise" such as walking, jogging, swimming, aerobic ball games or skiing.

On annual visits, if the doctor discovered that cholesterol level or blood pressure was high, the patient was advised to contact his or her doctor for treatment and follow-up.

At the study's end, researchers found that the incidence of diabetes was 58% lower in the intervention group than the comparison group. Among men the incidence was 63% lower; among women it was 54% lower. Those in the intervention group had made many more lifestyle changes than the others, and changes in weight, waist circumference, plasma glucose levels, serum insulin, serum lipids, and blood pressure were all significantly better in the intervention group.

The people in this study were counseled to do endurance exercises, to improve cardiorespiratory fitness and muscle strength. But merely becoming more active -- whether through "sports, household work, gardening, or work-related physical activity -- is similarly beneficial in preventing diabetes," Tuomilehto writes.

Even losing a small amount of weight made a difference, says Tuomilehto. "The effect of the intervention ... was most pronounced among subjects who made comprehensive changes in lifestyle." While the amount of weight lost was not large, those who lost at least 5% of their initial weight did not develop diabetes.

The message is clear, Sanders tells WebMD. "Being overweight -- and especially the presence of intra-abdominal fat -- is a very significant risk factor for development of type 2 diabetes. But lifestyle modification does make a difference ... individuals can benefit from weight loss, dietary modification, and exercise."


Often though, lifestyle changes are easier to plan than to do. This begs the question; will these methods work outside of a study? Tataranni writes the researchers believe they will, whether the people are Finnish or American. "Their optimism may be justified by the low dropout rate in their study -- less than 9% in the intervention group and less than 7% in the [comparison] group," he writes.

WebMD Health News Reviewed by Gary D. Vogin, MD
© 2001 WebMD, Inc. All rights reserved.