Hypothyroidism and meniere's disease: Insight from mendelian randomization study in a European population

Objectives Several observational studies have identified a link between hypothyroidism and Meniere's Disease (MD), but there is currently no reliable evidence of a causal relationship between the two conditions. We employed a novel data analysis approach, known as Mendelian randomization, to evaluate the potential causal link between hypothyroidism and MD. Methods Summary statistics for hypothyroidism and MD were obtained from the FinnGen Consortium, which included a total of 606,623 participants. The Inverse Variance Weighting (IVW) method served as the main approach for evaluating the causal link between hypothyroidism and MD, supplemented by four other methods. To confirm the reliability and robustness of the results, we applied Cochran's Q -test, the MR-Egger intercept test, and the leave-one-out analysis. Bidirectional MR analysis was also performed to address potential reverse causality bias. Results The random-effects IVW method showed no causal relationship between hypothyroidism and MD (OR = 0.972, 95% CI 0.913–1.034, p = 0.367). In a reverse analysis, there was no evidence that MD had an effect on hypothyroidism (OR = 1.021, 95% CI: 0.998–1.046, p = 0.076). The findings from the four additional Mendelian randomization methods aligned with the results obtained using the IVW approach. Furthermore, sensitivity analyses showed no horizontal pleiotropy or heterogeneity. Conclusion This MR study demonstrated no genetic causal relationship between hypothyroidism and MD, and hypothyroidism is not a risk factor for MD. Level of evidence Level 2.