Prediabetes and Multimorbidity: What a 21-Year Trial Follow-Up Suggests

For many adults with prediabetes, the goal has shifted from “prevent diabetes” to “protect healthspan”—keeping daily life healthier for longer. A new long-term follow-up from the NIH-supported Diabetes Prevention Program (DPP), published June 15, 2026, adds important context: intensive lifestyle intervention was linked to a lower risk of developing multiple chronic conditions over time, while metformin did not show a statistically significant multimorbidity reduction in this analysis.

Based on Medicare-linked follow-up data through 2021, the study looked beyond whether people developed diabetes. Instead, it assessed how often participants ended up with combinations of chronic diseases—what researchers call multimorbidity. The findings reinforce that structured, evidence-based lifestyle programs are a key prevention option, while medication decisions still need to be individualized.

What the study followed

This work builds on the original DPP randomized clinical trial (conducted from 1996 to 1999) in adults at high risk for type 2 diabetes. In the long-term follow-up, researchers used Medicare claims data (available through 2021) to measure “multimorbidity,” meaning having two or more chronic conditions. The analysis included 1,173 participants who were enrolled in Medicare and consented to claims linkage. The follow-up cohort was drawn from 27 U.S. clinical sites.

In the original DPP, participants were randomly assigned to one of three groups: intensive lifestyle intervention, metformin, or placebo. During the lifestyle program, the behavior change approach targeted eating changes, fewer calories and less fat, and at least 150 minutes of physical activity per week, with the goal of achieving ≥7% weight loss from baseline. After the initial intensive phase, participants received ongoing group-based lifestyle sessions over time.

Key finding: Lifestyle showed long-term multimorbidity benefits

By the end of follow-up, most participants had developed two or more chronic conditions. Among the lifestyle, metformin, and placebo groups, 82%, 85%, and 87% (respectively) experienced multimorbidity.

After statistical adjustment, the risk of multimorbidity was significantly lower with lifestyle than with placebo (hazard ratio 0.79, 95% CI 0.68–0.93). The NIH press release also reports that lifestyle was associated with lower risk for developing combinations of specific conditions—21% lower risk for having two chronic conditions and 25% lower risk for having three chronic conditions versus placebo.

Key finding: Metformin did not significantly reduce multimorbidity (in this analysis)

In contrast, participants originally assigned to metformin did not show a statistically significant reduction in multimorbidity compared with placebo (hazard ratio 0.91, 95% CI 0.78–1.07).

Notably, the multimorbidity relationship for lifestyle persisted even when diabetes was removed from the multimorbidity definition—suggesting the benefit was not only “because fewer people got diabetes.”

What this could mean for everyday prevention decisions in the U.S.

This study doesn’t suggest that one approach “beats everything” for every person. But it does support a practical, prevention-focused takeaway for the U.S. context: the kind of structured lifestyle support used in the DPP model can have benefits that extend beyond diabetes alone.

For many readers, that means it may be worth treating a lifestyle program as a long-term strategy for healthspan—not a short burst of motivation. The CDC’s National Diabetes Prevention Program (National DPP) is built to help people with prediabetes adopt sustainable changes through a trained lifestyle coach, group support, and both in-person and online delivery.

At the same time, medication choices (including metformin) still involve clinical tradeoffs for individuals—such as overall risk profile, other medical conditions, potential side effects, and personal preferences. This study focused on multimorbidity outcomes; it does not replace individualized clinician decision-making.

What readers can do now

If you’ve been told you have prediabetes, ask your clinician whether you qualify for an evidence-based lifestyle program (the National DPP model is the U.S. example).
Look for a structured program that includes coaching and ongoing support (not just a one-time nutrition class or generic gym membership).
Bring a short question list to your visit, such as: “What are my diabetes and chronic-disease risks?” “Would National DPP-style coaching fit my schedule?” and “When, if ever, is medication like metformin considered for someone like me?”
Plan for persistence: in the original DPP, lifestyle support continued beyond the early intensive phase, including ongoing group sessions. Prevention often depends on staying with the program long enough to build habits.

What remains uncertain

Even though the follow-up lasted over two decades, some limitations matter for how far we can generalize the results.

Who was studied: the multimorbidity analysis used Medicare-linked data from participants who consented to claims linkage and had a median age of 74. Results may not translate perfectly to younger adults, people without Medicare coverage, or other health-care systems.
How multimorbidity was measured: multimorbidity was defined from Medicare claims for a set of chronic conditions. That captures diagnoses that reach clinical care and billing, but it’s not the same as a full clinical evaluation for every condition.
Metformin timing and continuation: metformin use during the follow-up period was more complex than a simple “metformin vs. no metformin” comparison for every participant. The analysis is grounded in the original randomization, but real-world follow-up can differ.

Still, for U.S. readers thinking about chronic disease prevention, the bottom line is clear: an evidence-based, coach-led lifestyle program—delivered through the National DPP model—appears capable of reducing the long-term burden of developing multiple chronic conditions, at least in the Medicare population studied.

Key sources

Editorial note: Weence articles are researched from cited public-health, medical, regulatory, journal, and reputable news sources and may be drafted with AI assistance. They are checked for source support, clarity, and safety guardrails before publication.

This article is for general informational purposes only and is not medical advice. Research findings can be early or incomplete, and health guidance can change. Always talk with a qualified healthcare professional about personal symptoms, diagnosis, medications, vaccines, screenings, or treatment decisions. If you think you may have a medical emergency, call emergency services right away.