Look AHEAD: Action for Health in Diabetes

Short-term studies have shown numerous benefits of weight loss in overweight or obese patients, including improvements in glycemic control, risk factors for cardiovascular disease, quality of life, and other obesity-related coexisting illnesses. The Look AHEAD study was designed to test whether weight loss similarly improved cardiovascular morbidity and mortality in patients with type 2 diabetes. The study is a multicenter, randomized clinical trial that examines the long-term effects of an intensive lifestyle intervention program designed to achieve and maintain weight loss by decreased caloric intake and increased physical activity.

Eligible patients with type 2 diabetes and a body-mass index (BMI) of 25.0 or more were enrolled and randomly assigned either to participate in an intensive lifestyle intervention (intervention group) or to receive diabetes support and education (control group). The intensive lifestyle intervention, which included both group and individual counseling sessions, was aimed at achieving and maintaining weight loss of at least 7% by focusing on reduced caloric intake and increased physical activity. The diabetes support and education program featured sessions focusing on diet, exercise, and social support. Both the intervention and control programs occurred with decreasing frequency as the trial progressed. The primary outcome measure is the first occurrence of a composite cardiovascular outcome, which consists of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, and hospitalization for angina. Participants will be followed for a planned period of 13.5 years.

An ancillary study, Look AHEAD Brain, was conducted to assess whether participation in the 10-year lifestyle intervention, as part of Look AHEAD, had an impact on white matter hyperintensity and loss of brain tissue among individuals with type 2 diabetes. A subset of Look AHEAD study participants underwent standardized brain magnetic resonance imaging in conjunction with tests assessing cognitive function 10-12 years post-randomization.

The Look AHEAD intensive lifestyle intervention ended in September, 2012. Participants continued to be followed to determine the long-term effects of the intervention on health outcomes.

The Look AHEAD Continuation Study (Look AHEAD-C) builds on the Look AHEAD study to determine the long-term impact of an intensive lifestyle intervention on 1) physical function and mobility disability, and 2) cognitive function and cognitive impairment. Collection of cognitive function measures began in Year 8 of the study and continued through Year 13.

The current data package contains data through the end of the post intervention program.