Abstract
BACKGROUND: Emerging evidence suggests that coronavirus disease 2019 (COVID-19) infection may cause diabetes mellitus in patients without a prior history of the condition. OBJECTIVE: This review aims to determine the incidence of new-onset diabetes mellitus in COVID-19 patients compared to individuals without COVID-19, including rates of diabetic ketoacidosis, hyperglycaemia, mortality, and intensive care unit admission. Subgroup analyses will investigate patients receiving corticosteroid therapy for COVID-19, patients admitted to hospital due to COVID-19, and the incidence of new-onset diabetes mellitus in relation to diabetes mellitus worldwide. The incidence of new-onset diabetes mellitus post-infection after a 6-12-month follow-up will also be reported. METHODS: This protocol follows the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guidelines and is registered in PROSPERO (CRD42023457569). Eligible studies will include published and peer-reviewed cohort studies in English, after 1 December 2019. PubMed, Medline, Embase, and Scopus will be systematically searched. Included studies should compare new-onset diabetes mellitus incidence in COVID-19 patients against a control group without COVID-19. Two independent reviewers will extract data from included studies and assess risk of bias using the Newcastle-Ottawa quality assessment scale. A random-effects meta-analysis will compare the relative risk of new-onset diabetes mellitus post COVID-19 infection compared to non-infected individuals. CONCLUSION: The findings of this review will contribute to understanding the bidirectional relationship between COVID-19 and diabetes mellitus and inform clinical management strategies for patients at risk. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42023457569.