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. 2023 Jul 1;46(7):1432-1442.
doi: 10.2337/dc22-2539.

Metformin for Treatment of Acute COVID-19: Systematic Review of Clinical Trial Data Against SARS-CoV-2

Spencer M Erickson  1 , Sarah L Fenno  1 , Nir Barzilai  2 , George Kuchel  3 , Jenna M Bartley  3 , Jamie Nicole Justice  4 , John B Buse  5 , Carolyn T Bramante  6
Affiliations

Metformin for Treatment of Acute COVID-19: Systematic Review of Clinical Trial Data Against SARS-CoV-2

Spencer M Erickson et al. Diabetes Care. .

Abstract

Background: Observational and preclinical data suggest metformin may prevent severe coronavirus disease 2019 (COVID-19) outcomes.

Purpose: We conducted a systematic review of randomized, placebo-controlled clinical trials of metformin treatment for COVID-19 to determine whether metformin affects clinical or laboratory outcomes in individuals infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and present a structured summary of preclinical data.

Study selection: Two independent reviewers searched PubMed, Scopus, Cochrane COVID-19 Study Register, and ClinicalTrials.gov on 1 February 2023 with no date restrictions for trials where investigators randomized adults with COVID-19 to metformin versus control and assessed clinical and/or laboratory outcomes of interest. The Cochrane Risk of Bias 2 tool was used to assess bias.

Data extraction: Two reviewers extracted data pertaining to prespecified outcomes of each interest from each included trial.

Data synthesis: The synthesis plan was developed a priori and was guided by Synthesis Without Meta-analysis (SWiM) guidelines. Summary tables and narrative synthesis were used (PROSPERO, 2022, CRD42022349896). Three randomized trials met inclusion criteria. In two of the trials investigators found that metformin improved clinical outcomes (prevented need for oxygen and prevented need for acute health care use), and in the third trial a larger portion of adults with diabetes were enrolled but results did show a direction of benefit similar to that of the other trials in the per-protocol group. In the largest trial, subjects were enrolled during the delta and omicron waves and vaccinated individuals were included. The certainty of evidence that metformin prevents health care use due to COVID-19 was moderate per Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria. Many preclinical studies have shown metformin to be effective against SARS-CoV-2.

Limitations: Limitations include inclusion of only three trials and heterogeneity between trials.

Conclusions: Future trials will help define the role of metformin in COVID-19 treatment guidelines.

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Conflict of interest statement

Duality of Interest. C.T.B. is the principal investigator of a clinical trial investigating metformin for use in COVID-19 patients (clinical trial reg. no. NCT04510194, ClinicalTrials.gov) but did not receive compensation from any pharmaceutical company. No other potential conflicts of interest relevant to this article were reported.

Figures

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Graphical abstract
Figure 1
Figure 1
PRISMA diagram: selection of included studies (22).
See this image and copyright information in PMC

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