The association between living environmental factors and hearing loss in Chinese middle-aged and older adults: Results from a cross-sectional and longitudinal study hearing loss and living environment

BACKGROUND: Hearing loss (HL) substantially impairs quality of life and functional independence among middle-aged and older adults. Although individual environmental exposures have been associated with hearing health, the relationship between overall living environment quality and HL remains insufficiently understood. This study aimed to examine the association between a composite living environment score and HL in a nationally representative sample of Chinese adults. METHODS: Data were obtained from the China Health and Retirement Longitudinal Study (CHARLS). Cross-sectional analyses included 4,404 adults aged ≥ 45 years, and longitudinal analyses followed 3,603 participants without HL at baseline for up to 7 years. A composite living environment score (range: 0-6) was constructed based on ambient PM₂.₅ exposure, household fuel type, drinking water source, building type, and indoor temperature. Cross-sectional associations were assessed using logistic regression models, while longitudinal associations were assessed using Cox proportional hazards models. RESULTS: In cross-sectional analyses, higher living environment scores were inversely associated with prevalent HL (all P < 0.05). During longitudinal follow-up, 645 incident HL cases were identified. Each one-point increase in the living environment score was associated with a 5.7% lower risk of incident HL (fully adjusted hazard ratio [HR] = 0.943, 95% confidence interval [CI]: 0.889-0.999). Compared with participants in high-risk environments, those in low-risk environments showed a lower risk of HL (HR = 0.801, 95% CI: 0.638-1.005), with evidence of a dose-response relationship (P for trend = 0.038). Restricted cubic spline analyses indicated a linear association (P for nonlinearity > 0.05). CONCLUSION: Better overall living environment quality was associated with a lower risk of hearing loss among middle-aged and older adults, suggesting that improvements in living conditions may contribute to healthier auditory aging.