Metformin Is Associated with Favorable Outcomes in Patients with COVID-19 and Type 2 Diabetes Mellitus

Abstract

Aim: Coronavirus disease 2019 (COVID-19) is a new pandemic the entire world is facing since December of 2019. In this retrospective study, we aim to address whether metformin use offers a low mortality on patients with COVID-19 and pre-existing type 2 diabetes mellitus (T2DM). Materials and Methods: A cohort of 1356 hospitalized patients with COVID-19 and pre-existing T2DM was analyzed by multivariate regression. Covariates that potentially confound the association were further adjusted using propensity score matching or inverse probability of treatment weighting. A meta-analysis of the present study along with 5 published studies with metformin use prior to admission in patients with COVID-19 and T2DM was carried out. Results: We found that metformin therapy prior to admission in patients with COVID-19 and T2DM was significantly associated with less primary outcome events including in-hospital mortality and hospice care enrollment with an odds ratio (OR) of 0.25 (95% CI, 0.06-0.74) and less in-hospital length of stay, compared to non-metformin group. There were no statistical differences between the metformin group and non-metformin group for all three inflammatory markers (ferritin, CRP, and IL-6) on admission or peak levels during hospitalization. Furthermore, meta-analysis demonstrated that metformin use was significantly correlated with reduced mortality with an OR of 0.73 (95% CI, 0.65-0.82) in the fixed effect model and 0.58 (95% CI, 0.42-0.80) for the random effect model. Conclusions: Our results provide supporting evidence that metformin may confer increased survival in patients with COVID-19 and T2DM treated with Metformin prior to hospitalization