The Diabetes Prevention Program and Its Outcomes Study: NIDDK's Journey Into the Prevention of Type 2 Diabetes and Its Public Health Impact.
Level 5 - mechanism / opinion, no new human data
Narrative review summarizing the DPP randomized trial and DPPOS follow-up study
PubMed 40272279 · doi:10.2337/dc25-0014
What was done
This review summarizes the Diabetes Prevention Program (DPP) randomized clinical trial initiated in 1996 and its long-term follow-up, the Diabetes Prevention Program Outcomes Study (DPPOS) started in 2002. High-risk participants with prediabetes were randomized to an intensive lifestyle intervention (ILS), metformin, or placebo. The trial evaluated diabetes incidence over a mean of 2.8 years, and DPPOS tracked cumulative diabetes incidence, diabetes-free survival, and microvascular and cardiovascular outcomes over a median of 21 years of total follow-up.
What was found
At mean 2.8 years, diabetes risk was reduced by 58% with ILS and 31% with metformin compared with placebo. Over 21 years of median follow-up, cumulative diabetes incidence was reduced by 24% in the original ILS group and 17% in the metformin group, with median increases in diabetes-free survival of 3.5 and 2.5 years per person, respectively. There were no statistically significant effects of the original interventions on microvascular or cardiovascular outcomes during long-term follow-up; however, microvascular complication prevalence was significantly lower in participants who did not progress to diabetes compared to those who did.
Why it matters
This paper summarizes evidence that lifestyle modifications and metformin yield durable delays in type 2 diabetes onset over two decades. It also underscores that preventing progression to diabetes reduces microvascular risk, even if between-group differences in long-term vascular complications were not statistically significant.
Limits
The abstract is a narrative overview without sample sizes, cohort demographic characteristics, confidence intervals, or exact p-values. Long-term follow-up in DPPOS is subject to confounding from post-trial crossover and treatment changes, which may dilute long-term differences in cardiovascular and microvascular endpoints.
Cited by
- context In the Diabetes Prevention Program (DPP), a gentle lifestyle intervention was three times more effective than metformin.