IntroductionBaseline olfactory impairment, poor performance on cognitive test, and medial temporal lobe atrophy are considered biomarkers for predicting future cognitive decline in dementia-free older adults. However, the combined effect of these predictors has not been fully investigated.MethodsA group of 110 participants without dementia were continuously recruited into this study, and underwent olfactory, cognitive tests and MRI scanning at baseline and 5-year follow-up. Olfactory function was assessed using the University of Pennsylvania Smell Identification Test (UPSIT). Participants were divided into the cognitive decliners and non-decliners.ResultsAmong 87 participants who completed the 5-year follow-up, cognitive decline was present in 32 cases and 55 remained stable. Compared with non-decliners, cognitive decliners presented lower scores on both the UPSIT and the Montreal Cognitive Assessment (MoCA), and smaller hippocampal volume at baseline (all P < .001). The logistic regression analysis revealed that lower scores on UPSIT and MoCA, and smaller hippocampal volume were strongly associated with subsequent cognitive decline, respectively (all P < .001). For the prediction of cognitive decline, lower score on UPSIT performed the sensitivity of 63.6% and specificity of 81.2%, lower score on MoCA with the sensitivity of 74.5% and specificity of 65.6%, smaller hippocampal volume with the sensitivity of 70.9% and specificity of 78.1%, respectively. Combining three predictors resulted in the sensitivity of 83.6% and specificity of 93.7%.ConclusionsThe combination of olfactory test, cognitive test with structural MRI may enhance the predictive ability for future cognitive decline for dementia-free older adults.

中文翻译：

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多种早期生物标志物可预测无痴呆老年人的认知能力下降

简介基线嗅觉障碍、认知测试表现不佳和内侧颞叶萎缩被认为是预测无痴呆老年人未来认知能力下降的生物标志物。然而，这些预测因素的综合效应尚未得到充分研究。方法连续招募110名没有痴呆症的参与者参加本研究，并在基线和5年随访时进行嗅觉、认知测试和MRI扫描。使用宾夕法尼亚大学气味识别测试（UPSIT）评估嗅觉功能。参与者被分为认知下降者和非下降者。结果在完成5年随访的87名参与者中，32例出现认知下降，55例保持稳定。与非下降者相比，认知下降者在 UPSIT 和蒙特利尔认知评估 (MoCA) 上的得分较低，基线时海马体积较小（所有 P < .001）。逻辑回归分析显示，UPSIT 和 MoCA 得分较低以及海马体积较小分别与随后的认知能力下降密切相关（所有 P < .001）。对于认知能力下降的预测，UPSIT 得分较低，敏感性为 63.6%，特异性为 81.2%；MoCA 得分较低，敏感性为 74.5%，特异性为 65.6%；海马体积较小，敏感性为 70.9%，特异性为 70.9%。分别为 78.1%。结合三个预测因子，敏感性为 83.6%，特异性为 93.7%。 结论 嗅觉测试、认知测试与结构 MRI 的结合可能会增强对无痴呆老年人未来认知能力下降的预测能力。