Hearing aid use and gender differences in the auditory-cognitive cascade in the oldest old.

Objectives: This study analyzed cognitive differences between hearing-aid (HA) and non-HA users. We hypothesized that HA-use attenuates the auditory-cognitive cascade, thereby, the latter is more conspicuous in non-HA users. Since hearing impairment (HI) shows male predominance, we hypothesized gender differences within the auditory-cognitive relationship.

Methods: Non-frail community-dwellers ≥ 80 years were assessed for HI (pure tone audiogram-PTA; speech reception threshold-SRT) and global and domain-specific cognitive impairments (Mini-Mental State Examination-MMSE; Montreal Cognitive Assessment-MOCA; Reaction Time Test-RT1-4). Pearson and partial correlations (correcting for age and PTA) assessed auditory-cognitive associations within gender and HA subgroups. Fisher's z test compared correlations between HA and non-HA users.

Results: 126 participants (age range 80-91 years) were included. HA-use prevalence was 21%. HA-users were older with worse HI (mean PTA 49.5dBHL). HA-users exhibited no significant auditory (PTA, SRT) and cognitive (MMSE, MOCA, RT1- RT4) correlations. Male non-HA users, displayed a significant association between HI and global cognition, processing speed, selective and alternating attention. Significant differences were noted between MMSE and PTA and SRT (z-score 2.28, 3.33,  = 0.02, <0.01, respectively) between HA and non-HA users.

Conclusion: Male non-HA users displayed an association between HI and global and domain-specific (processing speed; selective and alternating attention) cognitive decline. Associations between global cognition and HI were significantly different between HA and non-HA users. This may be partially attributable to underlying subgroups sample sizes and statistical power disparity. If larger scale longitudinal or interventional studies confirm these findings, timely HI assessment and management may be the cornerstone for delaying cognitive decline.