The causal relationship between anxiety and tinnitus severity: a Mendelian randomization study

Abstract

Abstract Background The link between anxiety and tinnitus severity has garnered significant scholarly interest, with numerous studies identifying a positive correlation. Despite this, the genetic basis of this relationship remains underexplored. Leveraging publicly accessible GWAS data, this study employs Mendelian randomization to elucidate the genetic causality between anxiety and tinnitus severity. Methods This research analyzed single nucleotide polymorphisms (SNPs) related to anxiety and tinnitus severity from the UK Biobank, utilizing aggregated data from genome-wide association studies (GWAS). Instrumental variables linked to anxiety were meticulously selected. The study implemented several Mendelian randomization techniques, including “mr_ivw,” “mr_egger_regression,” “mr_weighted_median,” “mr_simple_mode,” and “mr_weighted_mode,” to assess the causal impact of anxiety on tinnitus risk through odds ratios (ORs). Sensitivity analyses, including MR-Egger and the leave-one-out method, were conducted to ensure result stability. The F-value was also calculated to ascertain the strength of the instrumental variables. Results Analysis identified five SNPs as instrumental variables. The calculated ORs and 95% confidence intervals from MR-Egger regression, weighted median, and inverse variance weighting showed no statistically significant causal relationship between anxiety and severe tinnitus, with all P-values exceeding 0.05. This lack of statistical significance, consistent across various methods, indicates no genetic causality between anxiety and tinnitus severity. Furthermore, no evidence of heterogeneity (P = 0.80) or horizontal pleiotropy (P = 0.31) was found, reinforcing the robustness of the instrumental variables (F > 10). Conclusion Our Mendelian randomization analysis reveals no genetic causality between anxiety and tinnitus severity, suggesting the need for further research into the multifaceted etiology of tinnitus.