S411 Effect of Histamine-2 Receptor Blockers Use on COVID-19 Susceptibility in Patients With Gastroesophageal Reflux Disease (GERD): A Population-Based Study

Abstract

Introduction: Studies have demonstrated that GERD is among the comorbidities that correlate with poorer outcomes in hospitalized patients with COVID-19. Proton pump inhibitors (PPI) increase the risk for enteric infections likely due to PPI effect on intra-gastric pH. However, evidence regarding the link between PPI use and COVID-19 is still conflicting. On the other hand, famotidine has been shown to correlate with improved clinical outcomes in hospitalized COVID-19 patients. We aimed to examine the relationship between COVID-19 risk and use of H2RB or PPIs in GERD patients. Methods: Data was extracted from a large commercial database (Explorys, IBM) that aggregates electronic health records from 26 large nationwide healthcare systems. Only adult patients with diagnosis of GERD from January 1999-May 2021 and COVID-19 from December 2019-May 2021 were included. Baseline characteristics including race, gender, H2RB or PPI use and health insurance type and status were collected. Incidence of COVID-19 among risk groups were examined. Univariable and multivariable logistic regression analyses were performed.The presence of effect modification by H2RB use was examined. Multivariate model was stratified by H2RB use. Results: We identified 6215670 GERD patients of which 4057825 (65%) were exclusive PPI users. A total of 1626345 (40%) used both H2RBs and PPIs and only 546930 (9%) used H2RBs alone. COVID-19 was diagnosed in 1140 (0.03%) patients using PPIs alone (62% females vs 38% males), 1300 (0.08%) users of both H2RB and PPI (68% females vs 32% males) and 190 (0.03%) patients using H2RBs alone (63% females vs 37% males). In univariate model, H2RB use was significantly associated with COVID-19 diagnosis OR 2.47 [2.29-2.66, P< 0.001]. COVID-19 risk was significantly modified if patient used both PPI and H2RB OR 1.92 [1.72-2.15, P< 0.001]. In multivariate model, after adjusting for covariates, PPI use was independently associated with COVID-19 diagnosis OR 3.4 [3.1-3.76, P< 0.001]. H2RB use alone was significantly associated with COVID-19 diagnosis OR 2.8 [2.35-3.2, P< 0.001]. But the use of both PPI and H2RB significantly reduced the risk of infection OR 0.63 [0.55-0.74, P< 0.001]. If the model was stratified by H2RB use, COVID-19 risk was reduced in PPI users but unchanged in patients regardless of their baseline demographics (Figure 1). Conclusion: In GERD patients, exclusive use of PPIs or H2RBs was significantly associated with COVID-19 diagnosis. Concurrent use may modify susceptibility to COVID-19.Figure 1.: Multivariable regression analysis stratified by histamine-2 receptor blockers (H2RB) use. A forest plot showing odds ratio (OR) and 95% confidence interval (CI) for the association between COVID-19 and select baseline demographic data in patients with gastroesophageal reflux disease (GERD).