Circulating levels of micronutrients and the risk of benign paroxysmal positional vertigo: A Mendelian randomization study.

Background: Benign paroxysmal positional vertigo (BPPV) is a typical vestibular disease characterized by recurrent episodes of vertigo. The role of micronutrients in BPPV pathogenesis has not been extensively studied, prompting this investigation into the relationship between circulating micronutrients and BPPV risk. This research aimed to explore the relationship between blood micronutrient levels and BPPV risk via Mendelian randomization (MR) analysis, a robust method for inferring causality from observational data. Methods: A total of 15 circulating micronutrients were assessed for their association with BPPV risk. MR analysis was conducted via the following methods: MR‒Egger, weighted median, simple model, inverse variance weighting (IVW), and weighted mode. Sensitivity analyses were performed to assess heterogeneity and pleiotropy. A multivariate MR analysis was also conducted, incorporating potential confounders such as trauma, chronic otitis media, hearing loss, peripheral atherosclerosis, ageing, and osteoporosis. Results: MR analysis revealed an obvious association between selenium and BPPV risk (OR 1.074, 95 % CI 1.005 to 1.148; P = 0.035). Folate was negatively related (OR 0.694, 95 % CI 0.501 to 0.962, P = 0.028) but was excluded because of inconsistent OR values across methods. Sensitivity analysis supported the IVW results, and there was no evidence of significant heterogeneity among the selenium-related instrumental variables included in the study, nor was horizontal pleiotropy detected among the instrumental variables. Multivariate MR analysis confirmed that selenium was an independent risk factor for BPPV (OR 1.22, 95 % CI 1.059 to 1.406, P = 0.006), with no significant associations observed for other micronutrients or exposure factors. Conclusion: This study provides evidence that blood selenium levels are positively associated with the risk of BPPV, suggesting a potential role for selenium in the pathogenesis of this disorder. These findings are robust to various sensitivity analyses and support the use of MR analysis to identify novel risk factors for BPPV. The identification of selenium as an independent risk factor for BPPV has implications for the development of preventive strategies and targeted interventions. It is necessary to analyse the biological mechanisms of this association and determine the therapeutic value of limiting selenium intake for BPPV to provide support for the treatment of such patients.