Sex differences in the association between the APOEε4 allele and hearing impairment: A longitudinal memory clinic study. (July 2021)

• Record Type: Journal Article
• Authors: Kim, Chi-Hun; Son, Kang Ju; Lee, Jun Hong; Kim, Jong Hun
• Is Part Of: Archives of gerontology and geriatrics. Volume 95(2021)
• Publication Date: 2021-07
• Subjects: Sex -- APOE -- Hearing impairment -- Alzheimer's disease -- Dementia -- Longitudinal; Aging -- Periodicals; Geriatrics -- Periodicals; Gerontology -- Periodicals; Electronic journals; 305.26
• DOI: 10.1016/j.archger.2021.104418
• Languages: English
• ISSNs: 0167-4943

Abstract

Highlights: Both APOE ε4 and hearing impairment (HI) are strong risk factors for dementia. The relationship between the APOE ε4 and HI has been controversial. The modifying effects of sex on the APOE ε4 may have contributed to the mixed results. In our longitudinal setting, male memory clinic visitors with APOE ε4 had a higher risk for HI. Some effects of APOE ε4 on dementia may be mediated by HI. Abstract: Background: The APOE ε4 allele and hearing impairment are risk factors for dementia. Cross-sectional studies have shown controversial findings regarding the relationship between APOE ε4 and hearing impairment. These may be explained by reported sex differences in the association between APOE ε4 and some Alzheimer's disease biomarkers. We aimed to investigate APOE ε4 and hearing impairment in a longitudinal setting considering the modifying effects of sex on APOE ε4. Methods: In total, 1810 subjects with APOE genotype at Ilsan Hospital memory clinics were linked to the longitudinal National Health Insurance Service database with International Statistical Classification of Diseases and Related Health Problems 10th revision (ICD-10) diagnosis codes of hearing impairment. After excluding cases with prevalent hearing impairment and incomplete records, 1092 subjects were analyzed for the period January 2004–July 2019. We used Cox proportional hazard models with or without adjustment for education, hypertension, diabetes, and cognitive function. Effect modification was analyzed by sex stratification and by adding APOE ε4 by sex interaction terms. Results: Hearing impairment did not differ between APOE ε4 carriers and non-carriers. Sex-stratification analysis with an unadjusted model showed men with APOE ε4 developed more hearing impairment than men without (HR 1.90, 95% CI 1.20–3.01), but women did not. The results remained similar in covariate-adjusted models. The interaction between APOE ε4 and sex was also significant regardless of adjustment. Conclusions: Our longitudinal analyses suggested male memory clinic visitors with APOE ε4 allele were more likely to develop hearing impairment than those without the genotype. This group may benefit more from regular monitoring and preventive measures for hearing impairment.