AUTHOR=Guo Ruixin , Zhang Yifan , Chen Yijie , Sha Wenqi , Kou Wanyi , Xu Chensi , Lei Yuran , Zhang Ningrui , Yang Liu , Guo Yun , Zhang Huihui , Wang Zhenghui TITLE=The causal relationship between obstructive sleep apnea and otitis media: a bidirectional Mendelian randomization study JOURNAL=Experimental Biology and Medicine VOLUME=Volume 250 - 2025 YEAR=2025 URL=https://www.ebm-journal.org/journals/experimental-biology-and-medicine/articles/10.3389/ebm.2025.10540 DOI=10.3389/ebm.2025.10540 ISSN=1535-3699 ABSTRACT=Obstructive sleep apnea (OSA) is manifested as periodic collapse of the upper airway during sleep. Otitis media is a spectrum of infectious and inflammatory diseases involving the middle ear. In this study, we sought to determine the causal effect of OSA on otitis media using a bidirectional, two-sample Mendelian randomization (MR) analysis. We analyzed the data from two different, extensive genome-wide association studies (GWAS) and selected OSA-related single-nucleotide polymorphisms (SNPs) as instrumental variables (IVs). Bidirectional MR analysis was conducted using the inverse-variance weighted (IVW) method. To ensure the robustness of the results, alternative sensitivity analysis procedures were performed, including MR-Egger, the MR pleiotropy residual sum and outlier (MR-PRESSO), and leave-one-out analysis. In the forward MR analysis, OSA was correlated with an increased risk of acute suppurative otitis media (odds ratio, 1.164; 95% confidence interval, 1.056–1.283; P = 0.002) and suppurative and unspecified otitis media (odds ratio, 1.150; 95% confidence interval, 1.059–1.249; P < 0.001). All reverse MR analyses showed that otitis media had no causal effect on OSA (P > 0.05). The MR analysis supports that OSA contributes to the development of otitis media. Thus, managing OSA may be beneficial in treating otitis media.