Qian, Z.J. et al. The American Journal of Geriatric Psychiatry. Published online: 12 April 2016

Objectives: Hearing loss is associated with cognitive decline in the elderly. However, it is unknown if the use of hearing aids (HAs) is associated with enhanced cognitive function.
Design: Cross-sectional study.
Setting: Academic medical center.
Measurements: Participants underwent audiometric evaluation, the Mini-Mental State Examination (MMSE), and the Trail Making Test, Part B (TMT-B). The impact of use versus disuse of HAs was assessed. Performance on cognitive tests was then compared to unaided hearing levels.
Results: HA users performed better on the MMSE (1.9 points; rank-sum, p=0.008) despite having worse hearing at both high frequencies (15.3 dB hearing level; t-test, p<0.001) and low frequencies (15.7 dB hearing level; t-test p<0.001). HA use had no effect TMT-B performance. Better performance on the MMSE was correlated with both low frequency (ρ=-0.28, p=0.021) and high frequency (ρ=-0.21, p=0.038) hearing level, but there was no correlation between performance on the TMT-B and hearing at any frequency.
Conclusions: Despite having poorer hearing, hearing aid users performed better on the MMSE. Better performance on cognitive tests with auditory stimuli (MMSE) but not visual stimuli (TMT-B) suggests that hearing loss is associated with sensory-specific cognitive decline rather than global cognitive impairment. As hearing loss is nearly universal in those >80 years, hearing aids should be strongly recommended to minimize the cognitive impairment in the elderly.
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