One-year effects of a group-based lifestyle intervention in adults with type 2 diabetes: A randomized encouragement trial

Abstract

AimsTo estimate the real-world effects of offering a group-based lifestyle intervention (GLI) to adults with diabetes. MethodsThis randomized encouragement trial included adult primary care patients in metropolitan Chicago with type 2 diabetes and body mass index ≥24 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. ResultsOf 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%; P = 0.02), and 1.20% weight loss at 12 months (95% CI, 0.05–2.36%; P = 0.04). At 12 months, there was a 0.30% (3.3 mmol/mol) reduction in hemoglobin A1c, but this result did not achieve statistical significance (P = 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%; P = 0.02), and 2.07% weight loss at 12 months (95% CI, 0.25–3.88%; P = 0.02). We detected no significant blood pressure or cholesterol effects. ConclusionsAmong adults with type 2 diabetes, a group-based lifestyle intervention in a community-based setting achieved modest weight loss at 6 and 12 months.Clinical trial registration: ClinicalTrials.gov Identifier NCT01435603.