Lifestyle interventions produce short-term improvements in glycemia and cardiovascular disease (CVD) risk factors in individuals with type 2 diabetes, but no long-term data are available. We examined the effects of a lifestyle intervention on changes in weight, fitness and cardiovascular (CVD) risk factors over 4 years.
Research Design and Methods
Look AHEAD is a multi-center randomized clinical trial comparing the effects of intensive lifestyle intervention (ILI) and diabetes support and education (DSE, control group) on the incidence of major CVD events in 5145 individuals with type diabetes, aged 45 to 76 years, who were overweight or obese (BMI > 25 kg/m2). Participants have ongoing intervention and annual assessments.
Averaged across four years of follow-up, participants in ILI had greater percent weight losses than those in DSE (−6.15% vs −0.88%, p<.0001) and greater improvements in fitness (12.74% vs. 1.96%, p < .0001), HbA1c (A1c, −0.36% vs. 0.09%, p<.0001), systolic blood pressure (SBP, −5.33 vs. −2.97 mmHg, p<.0001), diastolic blood pressure (DBP, −2.92 vs. −2.48 mmHg, p<.012), HDL-cholesterol (HDL-C, 3.67 vs. 1.97 mg/dl, p<.0001), and triglycerides (−25.56 vs. −19.75 mg/dl, p<.0006). Reductions in LDL-C were greater in DSE than ILI (−11.27 vs. −12.84 mg/dl, p=.009), but adjusted for medication use, changes in LDL-C did not differ between the two groups. Although the greatest benefits were often seen at 1 year, ILI participants still had greater improvements than DSE in weight, fitness, HbA1c, SBP, and HDL-C at 4 years.
Intensive lifestyle intervention can produce and maintain significant weight losses and improvements in fitness in individuals with type 2 diabetes. Across four years of follow-up, those in ILI had better overall levels of glycemic control, blood pressure, HDL-C and triglycerides, and thus spent considerable time with lower CVD risk. Whether this translates to reduction in CVD events will ultimately be addressed by the Look AHEAD study.