The Causal Effect of COVID-19 on Chronic Mastoiditis: A Bidirectional Two-Sample Mendelian Randomization-Based Study

Abstract

Abstract Background In the aftermath of COVID-19, individuals are experiencing long-term complications of the disease, making it imperative to study its organismal consequences. Although there have been sporadic studies with conflicting results on the relationship between COVID-19 and chronic mastoiditis (CM), a comprehensive investigation of this relationship is necessary, as CM can result in severe intracranial infections. Methods COVID-19 traits of varying severity were selected as exposures while chronic mastoiditis was selected as the outcome. Bidirectional univariable Mendelian randomization analyses were performed after rigorous screening of instrumental variables. Subsequently, mediation analyses were conducted to further investigate the underlying mechanisms. Results Univariable MR analysis suggested that there was a significant positive association between the infected COVID-19 and CM risk (OR = 2.574613, 95% CI 1.326495-4.997100, p = 0.005189). By contrast, the causal effect of hospitalized COVID-19 on CM (OR = 1.336397, 95% CI 1.060450–1.684149, p = 0.013995), as well as the causal effect of severe COVID-19 on CM (OR = 1.145725, 95% CI 0.978811–1.341102, p = 0.090380), are insignificant. Moreover, through mediation analysis, we found that “E-selectin levels” was the mediator of the causal effects of infected COVID-19 on CM (Indirect β = 0.673348, 95% CI, 0.081898–1.264798, the mediated proportion of 70.3%, p = 0.049373). Conclusion For the first time, we conducted a study to investigate the causal effects between three COVID-19 traits and chronic mastoiditis. Our findings indicate a significant causal effect of COVID-19 infection on CM. By contrast, the causal effects of hospitalized COVID-19 and severe COVID-19 on CM are insignificant. Moreover, we initially identified “E-selectin levels” as the mediator of the causal effect of infected COVID-19 on CM. Our finding enriches the types of COVID-19 sequelae and helps to prevent mastoiditis caused by COVID-19 in the early stage, thereby eliminating the possibility of intracranial infection and other serious complications.