Table 3_Peripheral and central auditory dysfunction, cardiometabolic multimorbidity, and cognitive performance in community-dwelling older adults: a cross-sectional study.docx

ObjectivesBoth age-related peripheral or central hearing loss, and cardiometabolic multimorbidity (CMM), which are independent association with global and domain-specific cognitive impairment, are common among older adults. Cardiometabolic diseases also are independent risk factors of age-related hearing loss. The first aim of the study was to investigate the independent and joint influence of CMM and low- and high-frequency hearing loss or central auditory processing dysfunction (CAPD) on global and domain-specific cognitive impairment. The second aim was to investigate whether CMM mediate the effects of age-related hearing loss on cognitive performance.
MethodsIn total, 508 eligible community-dwelling dementia-free older adult participants agreed to participate and completed a cross-sectional investigation. The averages of thresholds at 0.5, 1, and 2 kHz for low frequency (LPTA) and at 4, 6, and 8 kHz for high frequency (HPTA) were calculated. CAPD was assessed using SNR (signal-to-noise ratio threshold) in a words-in-noise test. Global and domain-specific cognitive performance was measured using a comprehensive neuropsychological test battery. This study analyzed the independent associations between LPTA, HPTA, CAPD, or CMM and global and domain-specific cognitive performance after adjusting for each other and other confounders. Weighted logistic regression were used to assess the joint effects of CMM and the LPTA, HPTA, or CAPD on cognitive performance. The R package “Mediation” was used to examine whether CMM mediated the associations between LPTA, HPTA, or CAPD and cognitive performance.
ResultsCMM was independently associated with global cognitive performance in pre-MCI [β (95% CI): 0.124 (0.047, 0.202), adjusted p = 0.0068], MCI groups [0.131 (0.055, 0.206), adjusted p = 0.068] for total sample, and the sensitivity test (adjusted p = 0.0506, and 0.012, respectively) after adjusted for all confounders. CMM in Model 2 was also significantly associated with executive function in the sensitivity test (β, 0.087; 95% CI, 0.028, 0.145; adjusted p = 0.035). The SNR value and global cognition in Model 2 was significantly associated between the cognitively normal group and the MCI group (adjusted p = 0.044 in total sample, and p = 0.051 in sensitivity test). HPTA in Model 2 remained independently associated with attention/executive function in the sensitivity test (β, 0.005; 95% CI, 0.001, 0.008; adjusted p = 0.0395). The dose–response relationships between the LPTA, HPTA, or SNR and CMM on global cognition were most significant in the cognitively normal group than in the MCI group. The significant joint effect of CMM and HPTA on executive function also been observed. In the sensitivity test, the indirect mediation effect of HPTA on global cognitive performance in the MCI group vs. the cognitively normal group after adjustments for all confounders through CMM were significant. Approximately 16.172% of the total effect of HPTA on global cognition was explained by the mediation effect through CMM.
ConclusionCMM and CAPD were significantly associated with global cognition. CMM and HPTA were significantly associated executive function in the sensitivity test. CMM, and LPTA, HPTA, or CAPD had jointly effects on global cognition. CMM and HPTA had significant joint effect on executive function. CMM might mediate the association between the HPTA and global or executive function in individuals with LPTA ≤ 40 dB HL. These findings indicated that an integrated interventional approach for presbycusis and CMM simultaneously may delay cognitive decline in older adults.

研究背景与目的：年龄相关性外周或中枢性听力损失（age-related peripheral or central hearing loss）与心血管代谢共病（cardiometabolic multimorbidity, CMM）均与全域及领域特异性认知障碍独立相关，且在老年人群中高发；同时心血管代谢疾病亦是年龄相关性听力损失的独立危险因素。本研究的首要目标为探讨CMM、高低频听力损失或中枢听觉处理功能障碍（central auditory processing dysfunction, CAPD）对全域及领域特异性认知障碍的独立与联合影响；其次旨在明确CMM是否介导年龄相关性听力损失对认知功能的作用。

研究方法：本研究共纳入508名符合纳入标准、居住于社区且无痴呆的老年受试者，完成了横断面调查。研究人员计算了0.5、1及2kHz频段的听阈均值（低频听阈均值，low frequency pure-tone average, LPTA）与4、6及8kHz频段的听阈均值（高频听阈均值，high frequency pure-tone average, HPTA）；采用词汇噪声测试中的信噪比（signal-to-noise ratio, SNR）阈值评估中枢听觉处理功能障碍。采用综合神经心理学测试组合评估全域及领域特异性认知功能。本研究在控制其他混杂因素及各变量间相互影响的前提下，分析了LPTA、HPTA、CAPD或CMM与全域及领域特异性认知功能的独立相关性；采用加权逻辑回归评估CMM与LPTA、HPTA或CAPD对认知功能的联合影响；使用R包"Mediation"检验CMM是否介导LPTA、HPTA或CAPD与认知功能之间的关联。

研究结果：在校正所有混杂因素后，全样本的轻度认知障碍前期（pre-MCI）组[β(95%CI)：0.124(0.047, 0.202)，校正后p=0.0068]与轻度认知障碍（MCI）组[0.131(0.055, 0.206)，校正后p=0.068]中，CMM均与全域认知功能独立相关；敏感性分析结果分别为校正后p=0.0506与p=0.012。模型2中的CMM在敏感性分析中亦与执行功能显著相关（β=0.087；95%CI：0.028, 0.145；校正后p=0.035）。在认知正常组与MCI组中，模型2的SNR值与全域认知功能显著相关（全样本校正后p=0.044，敏感性分析p=0.051）。模型2中的HPTA在敏感性分析中仍与注意/执行功能独立相关（β=0.005；95%CI：0.001, 0.008；校正后p=0.0395）。LPTA、HPTA或SNR与CMM对全域认知功能的剂量-反应关系在认知正常组中较MCI组更为显著。本研究还观察到CMM与HPTA对执行功能存在显著的联合影响。在敏感性分析中，经CMM介导的HPTA对MCI组相较于认知正常组的全域认知功能的间接中介效应在校正所有混杂因素后仍具有统计学意义。HPTA对全域认知功能的总效应中，约16.172%可通过CMM的中介效应予以解释。

研究结论：CMM与CAPD均与全域认知功能显著相关；在敏感性分析中，CMM与HPTA亦与执行功能显著相关。CMM与LPTA、HPTA或CAPD对全域认知功能存在联合影响；CMM与HPTA对执行功能存在显著联合影响。在LPTA≤40dB HL的受试者中，CMM可能介导HPTA与全域认知功能或执行功能之间的关联。本研究结果提示，同时针对老年性耳聋（presbycusis）与CMM开展整合式干预，或可延缓老年人群的认知衰退。