Metformin use before COVID-19 vaccination and the risks of COVID-19 incidence, medical utilization, and all-cause mortality in patients with type 2 diabetes mellitus

Abstract: Journal Pre-proofs Metformin use before COVID-19 vaccination and the risks of COVID-19 incidence, medical utilization, and all-cause mortality in patients with type 2 diabetes mellitus Fu-Shun Yen, Shiow-Ing Wang, Shih-Yi Lin, James Cheng-Chung Wei PII: DOI: Reference: S0168-8227(23)00454-0 https://doi.org/10.1016/j.diabres.2023.110692 DIAB 110692 To appear in: Diabetes Research and Clinical Practice Received Date: Revised Date: Accepted Date: 8 March 2023 14 April 2023 1 May 2023 Please cite this article as: F-S. Yen, S-I. Wang, S-Y. Lin, J. Cheng-Chung Wei, Metformin use before COVID-19 vaccination and the risks of COVID-19 incidence, medical utilization, and all-cause mortality in patients with type 2 diabetes mellitus, Diabetes Research and Clinical Practice (2023), doi: https://doi.org/10.1016/j.diabres. 2023.110692 This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2023 Published by Elsevier B.V. Metformin use before COVID-19 vaccination and the risks of COVID-19 incidence, medical utilization, and all-cause mortality in patients with type 2 diabetes mellitus Fu-Shun Yen a†, Shiow-Ing Wang b,c†, Shih-Yi Lin d,e, James Cheng-Chung Wei c,f,g,* a Dr. Yen’s Clinic, No. 15, Shanying Road, Gueishan District, Taoyuan 33354, Taiwan b Center for Health Data Science, Department of Medical Research, Chung Shan Medical University Hospital, No. 110, Sec. 1, Jianguo N. Rd., South District, Taichung 40201, Taiwan c Institute of Medicine, Chung Shan Medical University, No. 110, Sec. 1, Jianguo N. Rd., South District, Taichung 40201, Taiwan d Center for Geriatrics and Gerontology, Taichung Veterans General Hospital, No. 1650 Taiwan Boulevard, Sect. 4, Taichung 40705, Taiwan e Department of Medicine, School of Medicine, National Yang Ming Chiao Tung University, No. 155, Sec.2, Linong Street, Taipei 11221, Taiwan f Department of Allergy, Immunology & Rheumatology, Chung Shan Medical University Hospital, No. 110, Sec. 1, Jianguo N. Rd., South District, Taichung City 40201, Taiwan g Graduate Institute of Integrated Medicine, China Medical University, No. 91, Hsueh-Shih Road, Taichung 40402, Taiwan † Fu-Shun Yen and Shiow-Ing Wang contributed equally in this work. * Corresponding author. James Cheng-Chung Wei, Institute of Medicine, Chung Shan Medical University, No. 110, Sec. 1, Jianguo N. Rd., South District, Taichung 40201, Taiwan, Tel: +886 4 24739595 #34718, Fax: +886 4 24734323 E-mail addresses: yenfushun@gmail.com (F.S. Yen), shiowing0107@gmail.com (S.I. Wang), sylin@vghtc.gov.tw (S.Y. Lin), jccwei@gmail.com (J.C.C. Wei). 1 ABSTRACT Aims: We designed this study to determine whether metformin use before COVID-19 vaccination influences the risk of COVID-19 infection, medical utilization, and mortality. Methods: We used the US collaborative network of TriNetX to identify 123,709 patients with type 2 diabetes mellitus fully vaccinated against COVID-19 between January 1, 2020, and November 22, 2022. The study..