Abstract: Diabetes & Metabolic Syndrome: Clinical Research & Reviews 14 (2020) 2177e2183 Contents lists available at ScienceDirect Diabetes & Metabolic Syndrome: Clinical Research & Reviews journal homepage: www.elsevier.com/locate/dsx The Effect of Metformin Consumption on Mortality in Hospitalized COVID-19 patients: a systematic review and meta-analysis Antonia Anna Lukito a, *, 1, Raymond Pranata b, 1, Joshua Henrina c, Michael Anthonius Lim a, Sherly Lawrensia d, Ketut Suastika e a Department of Cardiology and Vascular Medicine, Siloam Hospitals Lippo Village, Tangerang, Indonesia Faculty of Medicine, Universitas Pelita Harapan, Tangerang, Indonesia RSUD Balaraja, Tangerang, Indonesia d Ken Saras General Hospital, Semarang, Indonesia e Head, Division of Endocrinology and Metabolism Department of Internal Medicine, Faculty of Medicine, Udayana University. Denpasar, Bali, Indonesia Denpasar, Bali, Indonesia b c a r t i c l e i n f o a b s t r a c t Article history: Received 29 October 2020 Received in revised form 4 November 2020 Accepted 6 November 2020 Background and aims: Diabetes is one of the most common comorbidities, and it is associated with poorer outcomes in patients with coronavirus disease 2019 (COVID-19). Preliminary findings showed that mortality was reduced in those who consume metformin compared to those who did not, and given its low cost and widespread availability; metformin is an attractive and potential agent to mitigate excessive risk in diabetic populations. Methods: Several medical databases (Pubmed, EuropePMC, EBSCOhost, Proquest, Cochrane library) and two health-science preprint servers (preprint.org and Medrxiv) were systematically searched for relevant literature. Results: Nine studies with 10,233 subjects were included in the qualitative and quantitative synthesis. Meta-analysis showed that metformin is associated with lower mortality in pooled non-adjusted model (OR 0.45 [0.25, 0.81], p ¼ 0.008; I2: 63.9%, p ¼ 0.026) and pooled adjusted model (OR 0.64 [0.43, 0.97], p ¼ 0.035; I2: 52.1%, p ¼ 0.064). Conclusion: The analysis showed that metformin consumption was associated with lower mortality. Randomized controlled trials are needed to confirm this finding. © 2020 Diabetes India. Published by Elsevier Ltd. All rights reserved. Keywords: COVID-19 SARS-CoV-2 Diabetes melitus Metformin Mortality