de Boer Tom G, Rigters Stephanie C, Croll Pauline H, Niessen Wiro J, Ikram M Arfan, van der Schroeff Marc P, Vernooij Meike W, Goedegebure André
Department of Otorhinolaryngology, Head and Neck Surgery, Erasmus University Medical Center, Rotterdam, the Netherlands.
Department of Epidemiology, Erasmus University Medical Center, Rotterdam, the Netherlands.
Ear Hear. 2022 May/Jun;43(3):933-940. doi: 10.1097/AUD.0000000000001148.
Recent studies have shown an association between poorer hearing thresholds and smaller brain tissue volumes in older adults. Several underlying causal mechanisms have been opted, with a sensory deprivation hypothesis as one of the most prominent. If hearing deprivation would lead to less brain volume, hearing aids could be hypothesized to moderate this pathway by restoration of hearing. This study aims to investigate whether such a moderating effect of hearing aids exists.
The authors conducted a cross-sectional study involving aging participants of the population-based Rotterdam Study. Hearing aid use was assessed by interview and hearing loss was quantified using pure-tone audiometry. Total brain volume, gray matter and white matter volume and white matter integrity [fractional anisotropy (FA) and mean diffusivity] were measured using magnetic resonance imaging. Only participants with a pure tone average at 1, 2, and 4 kHz (PTA1,2,4) of ≥35 dB HL were included. Associations of hearing loss with brain volume and global measures of white matter integrity were analyzed using linear regression, with hearing aid use and interaction between hearing aid use and PTA1,2,4 included as independent variables. Models were adjusted for age, sex, time between audiometry and magnetic resonance imaging, level of education, and cardiovascular risk factors.
Out of 459 included participants with mean age (range) 70.4 (52 to 92) 41% were female. Distributions of age and sex among hearing aid users (n = 172) did not significantly differ from those without hearing aids. PTA1,2,4 was associated with lower FA, but not with a difference in total brain volume, gray matter volume, white matter volume, or mean diffusivity. Interaction between hearing aid use and PTA1,2,4 was not associated with FA or any of the other outcome measures. Additional analysis revealed that interaction between hearing aid use and age was associated with lower FA.
We found no evidence for a moderating effect of hearing aids on the relationship between hearing loss and brain structure in a population of older adults. However, use of hearing aids did appear as an effect modifier in the association between age and white matter integrity. Future longitudinal research is needed to clarify these results.
近期研究表明，老年人听力阈值较差与脑组织体积较小之间存在关联。人们已经提出了几种潜在的因果机制，其中感觉剥夺假说是最突出的一种。如果听力剥夺会导致脑容量减少，那么可以推测助听器能够通过恢复听力来调节这一过程。本研究旨在调查助听器是否存在这种调节作用。
作者进行了一项横断面研究，纳入了基于人群的鹿特丹研究中的老年参与者。通过访谈评估助听器使用情况，并使用纯音听力测定法对听力损失进行量化。使用磁共振成像测量全脑体积、灰质和白质体积以及白质完整性[分数各向异性（FA）和平均扩散率]。仅纳入1、2和4千赫兹（PTA1,2,4）纯音平均听阈≥35分贝听力级的参与者。使用线性回归分析听力损失与脑容量和白质完整性总体指标之间的关联，将助听器使用情况以及助听器使用与PTA1,2,4之间的相互作用作为自变量纳入。模型对年龄、性别、听力测定与磁共振成像之间的时间间隔、教育程度和心血管危险因素进行了校正。
在纳入的459名平均年龄（范围）为70.4岁（52至92岁）的参与者中，41%为女性。助听器使用者（n = 172）的年龄和性别分布与未使用助听器者相比无显著差异。PTA1,2,4与较低的FA相关，但与全脑体积、灰质体积、白质体积或平均扩散率的差异无关。助听器使用与PTA1,2,4之间的相互作用与FA或任何其他结局指标均无关。进一步分析显示，助听器使用与年龄之间的相互作用与较低的FA相关。
在老年人群中，我们没有发现证据表明助听器对听力损失与脑结构之间的关系有调节作用。然而，在年龄与白质完整性之间的关联中，助听器的使用似乎是一个效应修饰因素。需要未来的纵向研究来阐明这些结果。
