Hearing Loss and Cognition Among Older Adults in a Han Chinese Cohort

Abstract

Presbycusis (PC) is associated with cognitive decline and incident dementia. Speech reception thresholds (SRT) are used to assess speech detection, which points toward a central component of PC. However, to the best of our knowledge, no previous study has reported the relationship between SRT and cognitive function in older adults in a Han Chinese cohort. Therefore, in this study, we investigate the association of hearing loss, indexed using pure tone average (PTA) and SRT, with cognitive function in a Han Chinese cohort using a standardized neurocognitive battery. Subjects (aged ≥60 years) with no history of psychiatric or neurological diseases were recruited. All subjects underwent a battery of neuropsychological and auditory tests. According to the PTA of the better ear, the subjects were further divided into PC and normal PTA (NP) groups. Regression analyses were performed to examine the relationship between cognitive function and hearing loss in the PC and NP groups and all subjects when controlling for age, sex, education level, diabetes, smoking, and hypertension. Cognitive function was significantly associated with PTA and SRT in all subjects. In all subjects, the correlations between non-verbal cognitive scores and SRT were stronger than those between non-verbal cognitive scores and PTA, whereas the correlations between verbal cognitive scores and PTA were stronger than those between verbal cognitive scores and SRT. Moreover, the correlations between PTA or SRT and cognitive function in the PC group were in principle stronger than those in the NP group. Our findings indicate that cognitive function is significantly associated with PTA and SRT in older adults in a Han Chinese cohort. Therefore, SRT could be an important auditory test for exploring cognitive decline in PC and could complement PTA.

Cognitive Flexibility and Inhibition in Individuals with Age-Related Hearing Loss

“…Findings related to group differences revealed that ARHL group demonstrated not only slower, but also worse, inhibitory control. On the Stroop color-word interference condition, the ARHL group took longer to complete the task relative to the NH group, which is consistent with the findings of most prior studies [37,39,59], with two exceptions [38,59]. Our finding suggests that the ARHL group required more time to successfully employ inhibitory control to perform the task with the same accuracy level as the NH group.…”

“…These processes are not specific to a particular modality, such as visual or auditory. In the context of ARHL, studies have predominantly investigated alterations in cognitive control processes by examining their associations with measures of peripheral hearing, primarily pure-tone average (PTA) [23,24,28,[34][35][36][37][38][39][40], with some recently examining associations with central hearing measures, particularly SiN recognition [35,[41][42][43][44][45][46].…”

“…Relative to working memory updating, fewer studies have examined cognitive flexibility in ARHL, with most using visual tasks. These studies have typically reported poorer accuracy on visual substitution measures such as the Digit Symbol and Letter Digit Substitution tests [23,[55][56][57][58], as well as longer completion time on the Trail Making Test-B (TMT-B) [24,38,39,59] in older adults with ARHL compared to normal hearing (NH) controls. Studies have also found significant associations between peripheral hearing loss and performance on measures of cognitive flexibility.…”

“…Also, few studies on ARHL have examined inhibition and the findings are rather inconclusive [24,28,[37][38][39]43,44,58,59,62]. While some have reported impairments in performance on visual Stroop measures, such as completion time [39], accuracy [24], and Stroop effect scores (which account for confounds of reading speed) [37] in those with mild [24,37,39] to severe [24] peripheral ARHL as compared to NH controls, others have not found any group differences on measures of Stroop [38,59]. Similarly, associations between peripheral hearing and inhibition are inconsistent.…”

“…Similarly, associations between peripheral hearing and inhibition are inconsistent. Some studies have found that greater hearing severity was related to longer completion times [39], lower accuracy [24], and worse Stroop effect scores [28,58], whereas others have not reported such significant findings using the visual Stroop [37,38,60] and adapted Simon task [62]. Evidence for asso-ciations between central hearing function measured using SiN recognition and inhibition in ARHL is inconclusive.…”