Design and participant characteristics for a randomized effectiveness trial of an intensive lifestyle intervention to reduce cardiovascular risk in adults with type 2 diabetes: The I-D-HEALTH study

Intervening in Diabetes with Healthy Eating, Activity and Linkages To Healthcare (I-D-HEALTH) is a community-based randomized trial evaluating the effectiveness of a group-based adaption of the Look AHEAD intensive lifestyle intervention. Most potentially eligible patients were identified through electronic medical record queries or referral to a diabetes resource hub. Trial enrollees had a usual source of primary care, elevated body mass index (BMI) and type 2 diabetes. I-D-HEALTH participants were randomized to either standard care alone or standard care plus free-of-charge access to a group-based lifestyle intervention (GLI) offered by the YMCA. GLI participation was encouraged, but not required, for the latter group. The primary outcome is percent weight change over 6, 12 and 24 months. Secondary outcomes include direct intervention costs and direct medical and non-medical expenditures, as well as changes in systolic blood pressure, hemoglobin A1c and cholesterol. Among 331 I-D-HEALTH participants, 167 were randomized to standard care and 164 to GLI. The mean age (±standard deviation) in each group was 57.1years (±12.2) and 57.6years (±10.5), respectively. Mean BMI was 34.9kg/m² (±7.3) among standard care participants and 36.2kg/m² (±7.8) among GLI participants. In both groups, approximately one third of participants were non-Hispanic Whites. We detected no significant differences between groups in mean systolic blood pressure, hemoglobin A1c or total cholesterol (P >0.05 for all characteristics above). The I-D-HEALTH study enrolled a diverse sample of adults with diabetes and offers a unique opportunity to evaluate the effectiveness of offering a community-based intensive lifestyle intervention.