Metformin Use is Associated with Lower Mortality in Veterans with Diabetes Hospitalized with Pneumonia
30 Pages Posted: 12 May 2022
Abstract
Introduction: Recent studies suggest that metformin use may be associated with improved infectious disease-related outcomes while other papers suggest potentially worse outcomes in serious bacterial infections. Our purpose was to examine the association of prior outpatient prescription of metformin on 30 and 90-day mortality for older veterans with pre-existing diabetes hospitalized with pneumonia.
Methods: We conducted a retrospective cohort study using national Department of Veterans Affairs data of patients > 65 years with a prior history of diabetes who were hospitalized with pneumonia over a 10-year period (fiscal years 2002-2012.) For our primary analysis, we created a propensity score and matched metformin users to non-users 1:1.
Results: We identified 36,990 patients who meet the inclusion criteria, 20.1% of which were prescribed metformin. Unadjusted 30-day mortality was 9.7% for those who received metformin versus 14.4% in non-users (p <0.0001), and 90-day mortality was 16.2% for those who received metformin versus 23.6% for non-users (p <0.0001). For the propensity score model, we matched 7,329 metformin users to 7,329 non-users. After propensity matching, both 30- (odds ratio [OR] 0.83, 95% confidence interval [CI], 0.75-0.92) and 90-day (OR 0.85, 95% CI, 0.77-0.92) mortality were significantly lower for metformin users.
Discussion: Prior receipt of metformin was associated with significantly lower mortality after adjusting for potential confounders. Additional research is needed to examine the safety of metformin use in patients with severe bacterial infections.
Note:
Funding Information: The project was supported by Grant Number R01NR010828 from the National Institute of Nursing Research.
Declaration of Interests: Authors TM, MB, AP, MP and EMM do not have any conflict of interest to disclose. CAA receives research grant from Boehringer Ingelheim and Merck, not associated with this submitted manuscript.
Ethics Approval Statement: We conducted a retrospective cohort study using the clinical and administrative databases of the Department of Veterans Affairs (VA) Health Care System. These databases are repositories of clinical data from the nationwide VA health care system. VA North Texas Institutional Review Board approved this study.
Keywords: Metformin, pneumonia, diabetes mellitus, AMP-activated protein kinase, mortality
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