Diabetes Prevention Program Trial - DPP
The goal of the trial was to evaluate whether treatment with metformin or a lifestyle modification intervention would be associated with the prevention or delay in development of diabetes in nondiabetic patients with elevated glucose and high risk for diabetes.
Patients Enrolled: 3,234
Mean Follow Up: Mean follow-up 2.8 years
Mean Patient Age: Mean age 51 years
Age ≥25 years, body mass index ≥24, and fasting plasma glucose of 95-125 mg/dl and 140-199 mg/dl two hours after a 75-g oral glucose load
Use of medications known to alter glucose tolerance or if they had illnesses that could seriously reduce their life expectancy or their ability to participate in the trial
Development of diabetes
Patients were randomized to 1) placebo (n=1,082), 2) metformin (n=850 mg twice daily) (n=1,073), or 3) a lifestyle-modification intervention (n=1,079) with a goal of ≥7% weight loss and ≥150 minutes of physical activity per week. The trial was designed to enroll half of patients from racial or ethnic minority groups.
Mean body mass index at baseline was 34.0 and baseline fasting glucose averaged 106.5 mg/dl. In the lifestyle intervention group, 50% achieved the goal of weight loss of ≥7% by 24 weeks and 74% achieved the goal of ≥150 minutes per week of physical activity. Caloric intake decreased by 249 kcal in the placebo group, 296 kcal in the metformin group, and 450 kcal in the lifestyle intervention group (p<0.001), while average weight loss was 0.1 kg, 2.1 kg, and 5.6 kg, respectively (p<0.001).
The primary endpoint of development of diabetes was highest in the placebo group (11.0 cases per 100 person-years), followed by the metformin group (7.8 per 100 person-years) and the lifestyle modification group (4.8 per 100 person-years), a 58% reduction for lifestyle versus placebo, 31% reduction for metformin versus placebo, and 39% reduction for lifestyle versus metformin. The incidence of diabetes at three years was 28.9% in the placebo group, 21.7% in the metformin group, and 14.4% in the lifestyle modification group. Gastrointestinal symptom adverse events were highest in the metformin group (77.8 per 100 person-years vs. 30.7 and 12.9 per 100 person-years for placebo and lifestyle groups, respectively). There was no significant difference in mortality (0.16, 0.20, and 0.10 per 100 person-years for placebo, metformin, and lifestyle modification, respectively).
Among nondiabetic patients with elevated glucose and at high risk for diabetes, use of a lifestyle intervention program was associated with a reduction in the development of diabetes compared with treatment with metformin or placebo. The development of diabetes in the metformin group, while not as low as the lifestyle intervention group, was lower than in the placebo group.
Development of diabetes is a costly and, as the present study demonstrates, preventable condition that is associated with an increased risk of cardiovascular disease and mortality. The data from the present study do not indicate which portion of the lifestyle modification intervention was responsible for the reduction in the development of diabetes or if it was a combination of multiple components. Additionally, patients in the present study were at high risk for development of diabetes, and it is unknown if such interventions would be effective in lower risk patients.
Knowler WC, Barrett-Conner E, Fowler SE, et al. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med 2002;346:393-403.
Keywords: Behavior Therapy, Life Style, Body Mass Index, Weight Loss, Metformin, Motor Activity, Energy Intake, Fasting, Diabetes Mellitus, Glucose
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