Overview
- The JAMA report, published June 16, 2026, analyzed Medicare claims for 1,173 participants from the Diabetes Prevention Program and found a 21% lower risk of multimorbidity for those randomized to the lifestyle intervention (hazard ratio 0.79).
- Metformin, given at 850 mg twice daily in the original trial, did not significantly reduce multimorbidity versus placebo over 21 years (hazard ratio 0.91, 95% CI 0.78–1.07).
- More than 80% of participants developed at least two chronic conditions by 2021, with final rates of 82% in the lifestyle arm, 85% with metformin, and 87% for placebo, and the study counted common conditions such as hypertension, heart disease, cancer, dementia, chronic kidney disease, depression, and diabetes.
- Progression to diabetes raised the risk of later multimorbidity by about 33% regardless of original treatment, underscoring how developing diabetes accelerates clustering of other chronic illnesses.
- Authors and editorialists note key caveats—the analysis used a Medicare subset that may not represent all people with prediabetes and adherence to metformin waned—and say the findings support investing in lifestyle programs while further studying whether newer weight-loss drugs change long-term multimorbidity and health spending.