ABSTRACT
AIMS: To estimate the real-world effects of offering a group-based lifestyle intervention (GLI) to adults with diabetes. METHODS: This randomized encouragement trial included adult primary care patients in metropolitan Chicago with type 2 diabetes and body mass index ≥24â¯kg/m2. Participants were randomized to standard care (brief dietary and lifestyle counseling) or standard care plus being encouraged, but not required, to participate in a free-of-charge GLI offered by the YMCA. The GLI was a group-based adaptation of the Look AHEAD lifestyle intervention. RESULTS: Of 331 participants, 167 were randomized to standard care and 164 to the GLI encouragement arm. About one third of participants were non-Hispanic White (34.4%). In the GLI arm, 75 (45.7%) attended ≥1 GLI visits. In the primary intention-to-treat analysis, the effect of GLI encouragement was 0.95% weight loss at six months (95% confidence interval [CI], 0.13-1.77%; Pâ¯=â¯0.02), and 1.20% weight loss at 12â¯months (95% CI, 0.05-2.36%; Pâ¯=â¯0.04). At 12â¯months, there was a 0.30% (3.3â¯mmol/mol) reduction in hemoglobin A1c, but this result did not achieve statistical significance (Pâ¯=â¯0.054). In instrumental variable analysis estimating effects among the subgroup of participants who attended any GLI visits, the effect of GLI attendance was 2.30% weight loss at six months (95% CI, 0.30-4.30%; Pâ¯=â¯0.02), and 2.07% weight loss at 12â¯months (95% CI, 0.25-3.88%; Pâ¯=â¯0.02). We detected no significant blood pressure or cholesterol effects. CONCLUSIONS: Among adults with type 2 diabetes, a group-based lifestyle intervention in a community-based setting achieved modest weight loss at 6 and 12â¯months. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT01435603.