High-Frequency Hearing Loss, Hippocampal Volume, and Motoric Cognitive Risk Syndrome in Older Adults in China: A Population-Based Study.

BACKGROUND

Little is known about the associations of hearing loss, hippocampal volume, and motoric cognitive risk syndrome (MCR) in older adults.

OBJECTIVE

We aimed to investigate the associations of hearing loss with MCR and hippocampal volume; and the interaction of hearing loss with hippocampal volume on MCR.

METHODS

This population-based cross-sectional study included 2,540 dementia-free participants (age≥60 years; 56.5% women) in the baseline examination of the Multimodal Interventions to Delay Dementia and Disability in rural China. Data were collected through face-to-face interviews, clinical examination, and laboratory tests. Hearing function was assessed using pure tone audiometry test. In the subsample (n = 661), hippocampal volume was assessed on structural magnetic resonance images. Data were analyzed with logistic regression models.

RESULTS

In the total sample, MCR was diagnosed in 246 persons (9.7%). High-frequency hearing loss was significantly associated with an increased likelihood of MCR and slow gait. In the subsample, the restricted cubic spline plots indicated an inverted U-shaped nonlinear relationship between high-frequency hearing performance and hippocampal volume. Moreover, greater hippocampal volume was significantly associated with a deduced likelihood of MCR and subjective cognitive decline (SCD). In addition, there were statistical interactions of high-frequency hearing loss with hippocampal volume on MCR and slow gait (p for interaction < 0.05), such that the associations were statistically significant only among participants free of high-frequency hearing loss.

CONCLUSIONS

High-frequency hearing loss was associated with an increased likelihood of MCR in older adults. The hippocampus might play a part in the relationship of high-frequency hearing loss and MCR.