Intensive Lifestyle Intervention for Overweight Patients with Diabetes — A Randomized Trial
Allan S. Brett, MD
The intervention didn't lower cardiovascular morbidity and mortality, but caveats apply.
We routinely advise lifestyle modification — particularly diet and exercise — for overweight patients with diabetes. In the NIH-supported Look AHEAD study, researchers aimed to show that intensive lifestyle change improves cardiovascular outcomes for these patients.
About 5000 overweight or obese patients with type 2 diabetes were assigned randomly to one of two groups. Those assigned to intensive lifestyle intervention received weekly counseling on diet and exercise (both individually and in groups) for the first 6 months, followed by monthly contact through 4 years; the goal was to lose 10% of body weight. The control intervention consisted only of three group sessions annually for 4 years. At baseline, median patient age and duration of diabetes were 59 years and 5 years, respectively. Mean weight was 101 kg, and mean body-mass index was 36 kg/m2. Mean glycosylated hemoglobin (HbA1c), blood pressure, and LDL cholesterol level were 7.3%, 129/70 mm Hg, and 112 mg/dL, respectively.
During median follow-up of 10 years, the primary composite outcome — cardiovascular death or the first occurrence of nonfatal myocardial infarction, stroke, or hospitalization for angina — occurred with similar frequency in the two groups (about 2 events per 100 person-years). During the first study year, measurable risk factors diverged substantially (favoring the intervention group), but by the end of the trial, differences between groups were minimal: Mean weight had decreased by about 7 kg and 5 kg in the intervention and control groups, respectively; HbA1c and blood pressure changed minimally in both groups; and LDL cholesterol levels fell by about 23 mg/dL in both groups.
Citation(s):
The Look AHEAD Research Group. Cardiovascular effects of intensive lifestyle intervention in type 2 diabetes. N Engl J Med 2013 Jun 24; [e-pub ahead of print]. (http://dx.doi.org/10.1056/NEJMoa1212914)
Gerstein HC. Do lifestyle changes reduce serious outcomes in diabetes? N Engl J Med 2013 Jun 24.
