Adults with elevated blood glucose (sugar) levels are at increased risk of developing type 2 diabetes. A recent study published in
The New England Journal of Medicine
heralds good news for people with elevated blood sugar levels: diet and exercise or the diabetes drug metformin (Glucophage) may reduce your risk of developing type 2 diabetes.
About the study
Between 1996 and 1999, researchers in the Diabetes Prevention Program Research Group enrolled 3234 men and women who did not have diabetes, but did have elevated blood glucose levels, into a study conducted at 27 different sites across the United States. Participants were aged 25 or older (average age 51) and had a body mass index (BMI) of 24 or higher. Sixty-eight percent of participants were women and 46% were members of minority groups. People were excluded from the study if they were taking medications known to alter blood glucose levels or had an illness that could shorten their life expectancy or impair their ability to participate in the study. The study ended in May 2001, with an average of 2.8 years of follow-up per participant.
Researchers randomly assigned 1073 participants to take the diabetes drug metformin, 1079 participants to an intensive lifestyle change program, and 1082 participants to take a placebo (inactive pill). People in the lifestyle change program were instructed to eat a healthy low-fat, low-calorie diet and exercise moderately for at least 150 minutes per week. They also attended one-to-one educational sessions for the first 24 weeks, where they received instruction on diet, exercise, and behavior modification. Throughout the remainder of the study, they attended individual and group brush-up sessions, usually monthly. In contrast, the placebo and metformin groups attended a yearly 20- to 30-minute individual session on healthy lifestyle and were given written lifestyle recommendations and encouraged to follow the Food Guide Pyramid and the National Cholesterol Education Program Step 1 diet.
When the study ended in May 2001, researchers compared the number of people who developed diabetes among the metformin group, the lifestyle change group, and the placebo group.
Both the lifestyle change program and metformin reduced the risk of diabetes, but the lifestyle-change program was more effective. Compared with the placebo group, the incidence of diabetes in the lifestyle change group was 58% lower and the incidence in the metformin group was 31% lower. In addition, the incidence of diabetes in the lifestyle-change group was 39% lower than in the metformin group.
The protective effects of lifestyle changes and metformin were consistent for all racial and ethnic groups and for both men and women. And there were some other interesting findings, as well. It appears that the lifestyle program was particularly effective for people aged 60 and older, whereas metformin was especially effective for people with higher BMI scores and higher fasting blood sugar levels.
There are limitations to this study, however. The people in the lifestyle change program underwent numerous individual counseling sessions to help them start and maintain new eating, exercise, and behavior habits. People who try to make lifestyle changes of this magnitude without such intensive counseling may not reap the same benefits. And like all studies of this kind, which rely on participants to adhere to their assigned regimens, there can be problems with compliance. However, compliance issues appear to have been fairly well controlled in this study.
How does this affect you?
If you have elevated blood sugar levels, you are at high risk of developing type 2 diabetes. The findings of this study suggest that adopting a healthy low-fat, low-calorie diet and exercising regularly can help you lose weight and reduce your chances of developing diabetes. The findings also suggest that, though somewhat less effective, the diabetes drug metformin can also reduce your risk of diabetes.
If your blood sugar is high, should you modify your eating and exercise habits or take metformin?
Diet and exercise were more effective than metformin in preventing the onset of diabetes. We know that these two lifestyle measures also may reduce your risk of heart disease, stroke, and certain cancers. So a diet and exercise program is a win-win strategy.
Because metformin is traditionally used to treat type 2 diabetes, its use in preventing diabetes may be considered somewhat atypical. If you are at high risk of developing type 2 diabetes, you may want to discuss these findings, which are quite noteworthy, with your health care provider.
Diabetes Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. New England Journal of Medicine
. February 7, 2002;346(6):393-403.
Please be aware that this information is provided to supplement the care
provided by your physician. It is neither intended nor implied to be a
substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER
IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the
advice of your physician or other qualified health provider prior to
starting any new treatment or with any questions you may have regarding a