Causal relationship between gastroesophageal reflux disease and the risk of chronic suppurative otitis media: a mendelian randomization analysis

Objectives: While existing research has indicated a potential link between gastroesophageal reflux disease (GERD) and chronic suppurative otitis media (CSOM), these findings primarily stem from observational studies, which are inherently limited by confounding variables and methodological biases, thereby reducing their reliability. This research sought to elucidate the causative link between GERD and CSOM. Methods: A two-sample bidirectional Mendelian randomization (MR) study was conducted using genetic data to assess the causal relationship between GERD and CSOM. Pooled genetic data for GERD and CSOM were obtained from published genomewide association studies. Independent single nucleotide polymorphisms, rigorously screened as instrumental variables, were used in the analysis. The primary analytical method was inverse variance weighting (IVW), with additional sensitivity analyses performed to assess the robustness and reliability of the results. Results: Per MR analysis, genetically predicted GERD positively associated with an increased CSOM risk (IVW: p = 0.001, odds ratio = 2.08, 95% confidence interval: 1.33–3.27). Per reverse MR analysis, genetically predicted CSOM did not associate with an increased GERD risk. Sensitivity analyses did not identify horizontal pleiotropy or heterogeneity. Conclusions: For the first time, GERD was identified as a risk factor for CSOM through a bidirectional MR study. This finding provides high-level causal evidence for the prevention and management of CSOM and forms a basis for future clinical and mechanistic studies. Clinicians should consider the potential impact of GERD when treating patients with CSOM, as GERD may be an important risk factor.