Infection Rates and Impact of Glucose Lowering Medications on the Clinical Course of COVID-19 in People with Type 2 Diabetes: A Retrospective Observational Study

Abstract

Purpose

Diabetes is a risk factor for COVID-19 severity, but the role played by glucose lowering medications (GLM) is still unclear. The aim of this study was to assess infection rates and outcomes of COVID-19 (hospitalization and mortality) in adults with diabetes assisted by the Local Health Unit of Padua (North-East Italy) according to the ongoing GLM.

Patients and Methods

People with diabetes were identified using administrative claims, while those with SARS-CoV-2 infection were detected by cross referencing with the local COVID-19 surveillance registry. A multivariate logistic regression model was used to verify the association between GLM classes and the outcome.

Results

SARS-CoV-2 infection rates were marginally but significantly higher in individuals with diabetes as compared to those without diabetes (RR 1.04, p = 0.043), though such relative 4% increase may be irrelevant from a clinical and epidemiological perspective. 1923 individuals with GLM-treated diabetes were diagnosed with COVID-19; 456 patients were hospitalized and 167 died. Those treated with insulin had a significantly higher risk of hospitalizations for COVID-19 (OR 1.48 p < 0.01) as were those treated with sulphonylureas/glinides (OR 1.34, p = 0.02). Insulin use was also significantly associated with higher mortality (OR 1.90, p < 0.01). Use of metformin was significantly associated with lower death rates (OR 0.62, p = 0.02). The association of other GLM classes with the outcome was not significant.

Conclusion

Diabetes does not appear to modify the risk of SARS-CoV-2 infection in a clinically meaningful way, but strongly increases the rates of hospitalization and death. Insulin use was associated with worse outcomes, whereas metformin use was associated with lower mortality.

Keywords:

• diabetes mellitus
• SARS-CoV-2
• antidiabetic drugs
• metformin
• hospitalization
• odds ratio
• administrative claims
• Veneto

Disclosure

Professor Angelo Avogaro reports grants and/or personal fees from Mundipharma, Astrazeneca, Lilly, Novo Nordisk, Amarin, Sanofi, Servier, and Amgen, outside the submitted work. Prof. Dr. Gian Paolo Fadini reports personal fees and/or grants from Abbott, AstraZeneca, Boehringer, Lilly, Novo Nordisk, Sanofi, Servier, and Takeda, outside the submitted work. The author reports no other conflicts of interest in this work.