Department of Psychiatry, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea.
Department of Psychiatry, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea.
Biomolecules. 2023 Aug 31;13(9):1336. doi: 10.3390/biom13091336.
Olfactory dysfunction is consistently observed in individuals with Alzheimer's disease (AD), but its association with beta-amyloid (Aβ) deposition remains unclear. This study aimed to investigate the relationship among olfactory function, cerebral Aβ deposition, and neuropsychological profiles in individuals with no cognitive impairment (NCI), mild cognitive impairment (MCI), and AD dementia. A total of 164 participants were included, and olfactory function was assessed using the brief smell identification test (B-SIT). Cerebral Aβ deposition was measured using [F]-flutemetamol PET imaging (A-PET). The results show a significant group difference in olfactory function, with the highest impairment observed in the Aβ-positive MCI and AD dementia groups, and the impairment was the lowest in Aβ-negative NCI. Olfactory dysfunction was positively associated with cognitive impairments across multiple domains. Furthermore, individuals with Aβ deposition had lower olfactory function compared to those without Aβ, even within the same neuropsychological stage. The association between olfactory dysfunction and Aβ deposition was observed globally and in specific cortical regions. These findings suggest that olfactory dysfunction is associated with both cognitive function and cerebral Aβ pathology in the trajectory of AD. Olfactory deficits may serve as an additional marker for disease progression and contribute to understanding the underlying mechanisms of AD.
嗅觉功能障碍在阿尔茨海默病（AD）患者中经常观察到，但它与β-淀粉样蛋白（Aβ）沉积的关系仍不清楚。本研究旨在调查无认知障碍（NCI）、轻度认知障碍（MCI）和 AD 痴呆患者的嗅觉功能、大脑 Aβ沉积与神经心理学特征之间的关系。共纳入 164 名参与者，使用简短嗅觉识别测试（B-SIT）评估嗅觉功能。使用 [F]-flutemetamol PET 成像（A-PET）测量大脑 Aβ 沉积。结果表明，嗅觉功能在组间存在显著差异，Aβ 阳性的 MCI 和 AD 痴呆组的嗅觉功能障碍最严重，而 Aβ 阴性的 NCI 组的嗅觉功能障碍最低。嗅觉功能障碍与多个认知领域的认知障碍呈正相关。此外，与无 Aβ 的个体相比，即使在相同的神经心理学阶段，有 Aβ 沉积的个体的嗅觉功能也较低。嗅觉功能障碍与 Aβ 沉积之间的关联在全脑和特定皮质区域均存在。这些发现表明，嗅觉功能障碍与 AD 轨迹中的认知功能和大脑 Aβ 病理学均有关。嗅觉缺陷可能作为疾病进展的附加标志物，并有助于理解 AD 的潜在机制。
