Environmental Risk Factors, Protective Factors, and Biomarkers for Hearing Loss: An Umbrella Review

Abstract Objective We aimed to investigate the potential environmental risk factors, protective factors, and biomarkers of hearing loss (HL), and establish a hierarchy of evidence. Data Sources Embase, PubMed, Cochrane Library, and Web of Science electronic database from inception to June 1, 2023. Review Methods We included meta‐analyses of observational studies of associations between HL and environmental risk factors, protective factors, or biomarkers. We calculated summary effect estimates, 95% confidence interval, heterogeneity I 2 statistic, 95% prediction interval, small study effects, and excess significance biases. Results Of the 9211 articles retrieved, 60 eligible articles were included. The 60 eligible articles identified 47 potential environmental risk and protective factors (N = 4,123,803) and 46 potential biomarkers (N = 173,701). Evidence of association was convincing (class I) for rheumatoid arthritis (RA) and every 1 cm increase in height. Evidence of association was highly suggestive (class II) for human immunodeficiency virus (HIV), diabetes, cumulative noise exposure (CNE), smoking, congenital cytomegalovirus (CMV) infection, combined exposure to organic solvents and noise, non‐Gaussian noise exposure, each 1 kg increase in birth weight, noise exposure, and alopecia areata (AA). Conclusion In this umbrella review, RA, every 1 cm increase in height, HIV, diabetes, CNE, smoking, congenital CMV infection, combined exposure to organic solvents and noise, non‐Gaussian noise exposure, each 1 kg increase in birth weight, noise exposure, and AA were strongly associated with HL.