Is Hearing Impairment Causally Associated With Falls? Evidence From a Two-Sample Mendelian Randomization Study

Area of Science:

• Genetics
• Epidemiology
• Public Health

Background:

• Observational studies suggest a link between hearing impairment (HI) and increased fall risk.
• The causal nature of this association requires further investigation.

Purpose of the Study:

• To investigate the causal association between hearing impairment and falls using a two-sample Mendelian randomization (MR) approach.
• To determine if genetically predicted hearing impairment influences the risk of falls.

Main Methods:

• Utilized summary data from large genome-wide association studies (GWAS) for hearing impairment (n=323,978) and falls (n=461,725).
• Employed inverse-variance weighted (IVW) as the primary MR analysis method, with weighted median, simple mode, weighted mode, and MR-Egger as complementary analyses.
• Performed sensitivity analyses including MR Steiger filtering, MR-Egger intercept test, MR-PRESSO, Cochran's Q statistic, and leave-one-out analysis to assess pleiotropy and heterogeneity.

Main Results:

• Identified 18 single nucleotide polymorphisms (SNPs) as valid instrumental variables.
• The IVW analysis indicated a significant causal association between genetically predicted hearing impairment and an increased risk of falls (OR 1.108, 95% CI 1.028-1.194, p=0.007).
• Sensitivity analyses confirmed the robustness and reliability of the findings, with no significant evidence of pleiotropy or heterogeneity.

Conclusions:

• This Mendelian randomization study provides strong evidence for a causal relationship between hearing impairment and an increased risk of falls.
• Effective management of hearing impairment is crucial for mitigating fall risks and improving overall quality of life.