Can insulin resistance and prediabetes be reversed?

Yes. Physical activity and weight loss help the body respond better to insulin. The Diabetes Prevention Program (DPP) was a federally funded study of 3,234 people at high risk for diabetes.

The DPP and other large studies proved that people with prediabetes can often prevent or delay diabetes if they lose a modest amount of weight by cutting fat and calorie intake and increasing physical activity—for example, walking 30 minutes a day, 5 days a week.

People at High Risk for Diabetes

DPP study participants were overweight and had prediabetes. Many had family members with type 2 diabetes. Prediabetes, obesity, and a family history of diabetes are strong risk factors for type 2 diabetes. About half of the DPP participants were from minority groups with high rates of diabetes, including African Americans, Alaska Natives, American Indians, Asian Americans, Hispanics/Latinos, and Pacific Islander Americans.

DPP participants also included others at high risk for developing type 2 diabetes, such as women with a history of gestational diabetes and people ages 60 and older.

Approaches to Preventing Diabetes

The DPP tested three approaches to preventing diabetes:

Making lifestyle changes. People in the lifestyle change group exercised, usually by walking 5 days a week for about 30 minutes a day, and lowered their intake of fat and calories.

Taking the diabetes medication metformin. Those who took metformin also received information about physical activity and diet.

Receiving education about diabetes. The third group only received information about physical activity and diet and took a placebo—a pill without medication in it.

People in the lifestyle change group showed the best outcomes. However people who took metformin also benefited. The results showed that by losing an average of 15 pounds in the first year of the study, people in the lifestyle change group reduced their risk of developing type 2 diabetes by 58 percent over 3 years.

Lifestyle change was even more effective in those ages 60 and older. People in this group reduced their risk by 71 percent.

People in the metformin group also benefited, reducing their risk by 31 percent. More information about the DPP, funded under NIH clinical trial number NCT00004992, is available at www.bsc.gwu.edu/dpp .