Cited by 494Diabetes Treatment and ManagementDiabetes, Cardiovascular Risks, and LipoproteinsPharmacology and Obesity Treatment

The DOI matches its Crossref record; 24 of the 24 references it cites were found in a registry or an index; none of the 15 sources its claims cite is checked for support yet.

Long-Term Safety, Tolerability, and Weight Loss Associated With Metformin in the Diabetes Prevention Program Outcomes Study

Open access
The Diabetes Prevention Program Research Group·2012·Diabetes Care

Abstract

OBJECTIVE: Metformin produced weight loss and delayed or prevented diabetes in the Diabetes Prevention Program (DPP). We examined its long-term safety and tolerability along with weight loss, and change in waist circumference during the DPP and its long-term follow-up. RESEARCH DESIGN AND METHODS: The randomized double-blind clinical trial of metformin or placebo followed by a 7–8-year open-label extension and analysis of adverse events, tolerability, and the effect of adherence on change in weight and waist circumference. RESULTS: No significant safety issues were identified. Gastrointestinal symptoms were more common in metformin than placebo participants and declined over time. During the DPP, average hemoglobin and hematocrit levels were slightly lower in the metformin group than in the placebo group. Decreases in hemoglobin and hematocrit in the metformin group occurred during the first year following randomization, with no further changes observed over time. During the DPP, metformin participants had reduced body weight and waist circumference compared with placebo (weight by 2.06 ± 5.65% vs. 0.02 ± 5.52%, P < 0.001, and waist circumference by 2.13 ± 7.06 cm vs. 0.79 ± 6.54 cm, P < 0.001 in metformin vs. placebo, respectively). The magnitude of weight loss during the 2-year double-blind period was directly related to adherence (P < 0.001). Throughout the unblinded follow-up, weight loss remained significantly greater in the metformin group than in the placebo group (2.0 vs. 0.2%, P < 0.001), and this was related to the degree of continuing metformin adherence (P < 0.001). CONCLUSIONS: Metformin used for diabetes prevention is safe and well tolerated. Weight loss is related to adherence to metformin and is durable for at least 10 years of treatment.

Overview

AI snapshot

Written from the paper’s full text.

TL;DR

In the Diabetes Prevention Program and its Outcomes Study, metformin for diabetes prevention showed no significant safety issues, was well tolerated, and produced modest durable weight loss. Weight loss was directly related to metformin adherence and persisted over long-term follow-up.

Key findings

  • During the DPP, metformin vs placebo reduced body weight (2.06 ± 5.65% vs. 0.02 ± 5.52%, P < 0.001) and waist circumference (2.13 ± 7.06 cm vs. 0.79 ± 6.54 cm, P < 0.001); at 2 years, weight loss was 2.1 ± 5.7% vs. 0.02 ± 5.5%.
  • Gastrointestinal symptoms were more common with metformin than placebo (average 28% vs. 16%, P = 0.01; medication-related 9.5% vs. 1.1%, P < 0.001) and declined over time, with similar rates by years 6–9 (P > 0.10).
  • Hemoglobin and hematocrit were slightly lower in the metformin group during the DPP (13.6 vs. 13.8 mg/dL; 40.6 vs. 41.1%; P < 0.001 for both), with changes occurring in the first year and no further changes; low hematocrit was higher with metformin (12.6% vs. 8.4%, P = 0.035), while low hemoglobin was not significantly different (11.2% vs. 7.6%, P = 0.17).
  • Over total follow-up, weight loss remained greater with metformin than placebo (2.0% vs. 0.2%, P < 0.001) and was related to continuing metformin adherence (P < 0.001); highly adherent metformin participants lost 3.5% (3.1 kg). No lactic acidosis or hypoglycemia serious adverse events occurred during nearly 18,000 patient-years.

Methods

  • Randomized double-blind trial: 3,234 participants enrolled in the DPP; 2,155 assigned to metformin (1,073) or placebo (1,082), followed by a 7–8-year open-label DPPOS extension. Participants were ≥25 years, had BMI ≥24 kg/m² (≥22 kg/m² in Asian Americans), elevated fasting glucose, and impaired glucose tolerance.
  • Adverse events were collected by quarterly queries during the DPP and annual gastrointestinal symptom questions; weight was measured twice yearly, waist circumference annually, and hemoglobin/hematocrit annually. Adherence was assessed by pill counts as ≥80% or <80%.
  • Analyses covered the first 2 years of double-blind treatment and the full follow-up period; fixed-effects repeated-measures models adjusted for baseline weight and waist circumference, and generalized estimating equations assessed symptoms and adverse events over time.

Limitations

  • Stated: 12% of DPP participants chose not to continue into the DPPOS; some may have discontinued or declined open-label metformin because of side effects, potentially influencing the safety and tolerability profile during the open-label DPPOS period.
  • Stated/implied: the adherence–weight analyses were post hoc, adherence was not randomized, and placebo was discontinued during the open-label phase so adherence could not be assigned for placebo.
  • Evident: the open-label DPPOS phase was unblinded, and adherence categories may be confounded by tolerability, health behaviors, or reasons for low adherence; the paper notes that low-adherence metformin and placebo groups would not be expected to have the same characteristics.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.2337/dc11-1299

Cites

24 of 24 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Verification

Claims the paper makes

0 of 15 cited sources checked · 0 supported · 0 flagged

Show all 36 claims

  • It may state two separate claims as one. 20
  • Probably not a substantial claim. 1
20 of 20

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Combined adherence categories described as highly adherent

    Minor

    The conclusions say that 72% of metformin participants during the double-blind phase and 62% over the full trial were highly adherent. The results say those percentages include participants in either the ≥50% adherent or the highly adherent category.

1 of 1

Citations

Cites

Flagged first, then by citations

Show all 24 references

Cited by

Sorted by citations

Items 101–200 of 493

Metadata

Authors
The Diabetes Prevention Program Research Group
Affiliations
Pennington Biomedical Research Center (US)
Corresponding author
The Diabetes Prevention Program Research Group
Venue
Diabetes Care
Published
2012-03-13
Volume
35
Issue
4
Pages
731-737
ISSN
  • 0149-5992 (ISSN-L)
  • 1935-5548
OpenAlex
W2096559770
Cited by
494
References
24
Citations by year
2026: 19 · 2025: 34 · 2024: 68 · 2023: 44 · 2022: 31 · 2021: 51 · 2020: 36 · 2019: 35 · 2018: 36 · 2017: 25 · 2016: 28 · 2015: 35 · 2014: 19 · 2013: 22 · 2012: 10
FWCI
22.06
Type
journal article
Language
en
Open access
Licence
cc-by-nc-nd
Locations
  • Diabetes Care (publishedVersion, cc-by-nc-nd)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by-nc-nd)
  • PubMed Central (publishedVersion, cc-by-nc-nd)
  • PubMed (publishedVersion)
  • Hispana (submittedVersion)
  • Lund University Publications (Lund University) (submittedVersion)
Funders
  • National Institutes of Health
  • National Institute of Diabetes and Digestive and Kidney Diseases (P30DK017047)
Topics
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Diabetes Treatment and Management
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Diabetes, Cardiovascular Risks, and Lipoproteins
  • Health Sciences › Medicine › Pharmacology (medical) › Pharmacology and Obesity Treatment
Keywords
metformin, diabetes prevention, long-term safety, tolerability, weight loss, waist circumference, gastrointestinal adverse effects, hemoglobin, hematocrit, medication adherence, type 2 diabetes prevention, open-label extension
MeSH terms
Adult, Aged, Aged, 80 and over, Diabetes Mellitus, Type 2, Double-Blind Method, Female, Follow-Up Studies, Humans, Hypoglycemic Agents, Male, Metformin, Middle Aged, Placebos, Prediabetic State, Time Factors, Weight Loss, Treatment Outcome

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

A language model drew the claims from the paper on 2026-10-10, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).

A second model labelled each claim on 2026-10-10 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review