[A study on the major chronic diseases and hearing impairment among middle-aged and older adults in China]

Objective: To explore the association between major chronic diseases and their cumulative number and the risk of hearing impairment in middle-aged and older adults in China. Methods: Based on data from the China Health and Retirement Longitudinal Study from 2011 to 2020, middle-aged and older adults without hearing impairment in 2011 were included as the baseline population. Follow-up for hearing impairment outcomes was conducted in 2013, 2015, 2018, and 2020. A multivariate Cox proportional hazards regression model was used to analyze the association between major chronic diseases, their cumulative number, and the risk of hearing impairment, with HRs and 95%CIs calculated. Subgroup analyses were performed by age (<65 years and ≥65 years) and sex. Results: Among the 8 144 middle-aged and older adults included in the study, with a mean follow-up of 7.78 person-years, 1 094 new cases of hearing impairment were identified, yielding an incidence density of 17.68 per 1 000 person-years. The multivariate Cox proportional hazards regression model analysis revealed that, for individual major chronic diseases, diabetes (HR=1.27, 95%CI: 1.01-1.60), heart disease (HR=1.66, 95%CI: 1.40-1.96), arthritis (HR=1.20, 95%CI: 1.06-1.37), and chronic kidney disease (HR=1.29, 95%CI: 1.02-1.62) were statistically significantly associated with hearing impairment risk. In contrast, hypertension, chronic lung disease, and stroke showed no statistically significant association with hearing impairment. Compared with middle-aged and older adults without any major chronic diseases, the HRs (95%CIs) for individuals with a cumulative number of 1, 2, and ≥3 major chronic diseases were 1.24 (1.07-1.43), 1.51 (1.27-1.79), and 1.86 (1.50-2.31), respectively, indicating a significant trend of increasing risk of hearing impairment with a greater number of chronic diseases (P<0.001). Subgroup analyses indicated that having 1, 2, and ≥3 major chronic diseases increased the risk of hearing impairment in both middle-aged adults (<65 years) and older adults (≥65 years). However, the trend was more pronounced in the <65 years age group compared to the ≥65 years group. Additionally, males were more susceptible to the effects in the early stages, whereas females exhibited a cumulative increase in risk. Conclusions: Major chronic diseases and their cumulative number are risk factors for hearing impairment. In the prevention and control of hearing impairment, focused attention should be given to middle-aged and older adults with major chronic diseases. Furthermore, in clinical practice, emphasis should be placed on gender-specific considerations, which will be of significant importance for the early prevention and intervention of hearing impairment.