Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2012 Apr;35(4):731-7.
doi: 10.2337/dc11-1299.

Long-term safety, tolerability, and weight loss associated with metformin in the Diabetes Prevention Program Outcomes Study

Diabetes Prevention Program Research Group  1
Collaborators, Affiliations
Randomized Controlled Trial

Long-term safety, tolerability, and weight loss associated with metformin in the Diabetes Prevention Program Outcomes Study

Diabetes Prevention Program Research Group. Diabetes Care. 2012 Apr.

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.

Trial registration: ClinicalTrials.gov NCT00004992 NCT00038727.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Effect of adherence to metformin or placebo on percent weight change (A and B) and change in waist circumference (C and D) during 2 years of treatment during the double-blind phase of the DPP.
Figure 2
Figure 2
Change in weight (A) and change in waist circumference (B) throughout the DPP and the DPPOS by placebo and adherence to metformin.
Figure 3
Figure 3
Self-reported gastrointestinal (GI) problems (A) and gastrointestinal symptoms attributed to study medication (B) through the DPP and the DPPOS.
See this image and copyright information in PMC

Comment in

References

    1. DeFronzo RA. Pharmacologic therapy for type 2 diabetes mellitus. Ann Intern Med 1999;131:281–303 - PubMed
    1. UK Prospective Diabetes Study (UKPDS) Group Effect of intensive blood-glucose control with metformin on complications in overweight patients with type 2 diabetes (UKPDS 34). Lancet 1998;352:854–865 - PubMed
    1. Bray GA, Greenway FL. Pharmacological treatment of the overweight patient. Pharmacol Rev 2007;59:151–184 - PubMed
    1. Knowler WC, Barrett-Connor E, Fowler SE, et al.; Diabetes Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med 2002;346:393–403 - PMC - PubMed
    1. Crandall JP, Knowler WC, Kahn SE, et al. ; Diabetes Prevention Program Research Group The prevention of type 2 diabetes. Nat Clin Pract Endocrinol Metab 2008;4:382–393 - PMC - PubMed

Publication types

MeSH terms

Associated data