AUTHOR=Liang Zheng , Li Ao , Xu Yuanyuan , Qian Xiaoyun , Gao Xia 

TITLE=Hearing Loss and Dementia: A Meta-Analysis of Prospective Cohort Studies

JOURNAL=Frontiers in Aging Neuroscience

VOLUME=Volume 13 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2021.695117

DOI=10.3389/fnagi.2021.695117

ISSN=1663-4365

ABSTRACT=Background: Consensus lacks regarding whether hearing loss is an independent risk factor for dementia. We therefore conducted a meta-analysis to clarify the relationship of hearing loss and dementia.

Methods: Prospective cohort studies investigating the association between hearing loss and the incidence of dementia in a community-derived population were included by search of electronic databases that included PubMed, Embase, and Cochrane’s Library. A random-effects model was adopted to combine the results.

Results: Fourteen cohorts including 726,900 participants were analyzed. It was shown that hearing loss was independently associated with dementia (adjusted hazard ratio [HR]: 1.59, 95% confidence interval [CI]: 1.37 to 1.86, P < 0.001; I2 = 86%). Sensitivity analysis sequentially excluding any of the individual studies included showed similar results. Subgroup analysis according to the diagnostic methods for hearing loss, validation strategy for dementia, follow-up duration, and adjustment of apolipoprotein E genotype also showed consistent results (P values for subgroup differences all > 0.05). Meta-analysis with five studies showed that hearing loss was also connected to higher risk of Alzheimer’s disease (adjusted HR: 2.24, 95% CI: 1.32 to 3.79, P = 0.003; I2 = 2%).

Conclusions: Hearing loss may increase the risk of dementia in the adult population. Whether effective treatment for hearing loss could reduce the incidence of dementia should be explored in the future.