1119-P: Persistent and Heterogeneous Long-Term Effects of the Diabetes Prevention Program (DPP) Intensive Lifestyle (ILS) Intervention on Diabetes Incidence

During the three years of the DPP, ILS reduced incidence of diabetes compared with placebo in high-risk adults. Diabetes was defined using ADA criteria based on 1) annual OGTT or semi-annual fasting glucose (the primary DPP outcome, diab-G, hazard ratio (HR) =0.42 and rate difference (RD) = -6.2 cases/100 person-years) or 2) annual HbA1c ≥ 6.5% (diab‑A1C, HR=0.51 and RD = -4.2) . After DPP ended, participants were unmasked, placebo was discontinued, and all participants were offered group-based ILS and followed in the DPP Outcomes Study. We now compare the original ILS and placebo groups over a mean of 21 years since randomization. We test heterogeneity across subgroups defined by demographics and baseline glucose, HbA1c, BMI, and history of gestational diabetes and express it by interaction p-values (P-het) . During the total follow-up, ILS, compared with placebo, significantly reduced incidence of diab‑G: HR=0.76 (95% CI=0.68, 0.85) , RD= -1.62 (-2.28, -0.97) and of diab-A1C: HR=0.80 (0.70, 0.92) , RD= -1.67 (‑2.24, -1.10) . Effects on diab-G were homogenous across subgroups except for fasting glucose (P-het