Interactive effects of hearing aid use and cognitive function in patients with hearing loss

Background: There has been a significant increase in scientific investigations of the hearing-dementia association among the research on potentially modifiable risk factors for cognitive impairment. We tested two clinical questions. Analysis 1: does persistent hearing aid (HA) use decrease the decline in cognitive function caused by ageing? Analysis 2: does cognitive function at the time of HA fitting predict future persistent HA use?. Methods: This case–control study performed at two referral centres reported data obtained over a 4.5-year period. We recruited a group of patients with cognitive decline, aged 65 or older with or without hearing loss. The intervention consisted of the use of HAs. The primary outcome measures were adherence to continuous HA use and cognitive function measured using the Japanese version of the Mini-Mental State Examination Test and the Reading Cognitive Test Kyoto. Results: Eighteen HA users and 18 controls were included in the first analysis. HA use was associated with a deceleration of cognitive decline 12 months later. In the second analysis, 11 participants with good adherence to HA use were compared with 12 participants who showed poor adherence to HA use. Among the variables employed in this study, cognitive function measured using the Reading Cognitive Test Kyoto was significantly lower in participants with poor adherence to HA. Conclusions: HA use in cognitively impaired individuals with hearing loss can slow age-related cognitive decline. Cognitively impaired people with hearing loss who fail to commit to HA use tend to have lower cognitive measurement scores before HA fitting. HA use is generally more challenging as people age and their cognitive abilities decline. Therefore, it is desirable that HAs be used when hearing loss and dementia are in their early stages.