Department of Physical Therapy, University of British Columbia (UBC), Vancouver, Canada.
Djavad Mowafaghian Centre for Brain Health, Vancouver Coastal Health Research Institute, Vancouver, Canada.
J Alzheimers Dis. 2019;71(s1):S41-S49. doi: 10.3233/JAD-180848.
Impaired physical function (i.e., slowing of gait, muscle weakness, and poor mobility) is common in older adults with cognitive impairment and dementia. Evidence suggests that cerebral small vessel disease, specifically white matter lesions (WMLs), is associated with impaired physical function, but little research has been conducted to understand the specific role of Alzheimer's disease pathology in physical outcomes.
The objective of this study was to examine the association between cerebral amyloid-β (Aβ) deposition and physical function in people with cognitive impairment.
Thirty participants completed an 11C Pittsburgh compound B (PIB) position emission tomography (PET) scan to quantify global Aβ deposition using standardized uptake value ratio (SUVR). We assessed usual gait speed, muscle strength of the lower extremities, balance, and functional mobility using the Short Physical Performance Battery (SPPB) and the Timed Up and Go Test (TUGT). Multiple linear regression analyses examined the association between Aβ and each measure of physical function, adjusting for age, body mass index, and WML load.
Global PIB SUVR was significantly associated with usual gait speed (β= -0.52, p = 0.01) and SPPB performance (β= -0.47, p = 0.02), such that increased Aβ deposition was associated with reduced performance on both measures. Global PIB SUVR was not significantly associated with TUGT performance (β= 0.32, p = 0.08).
Cerebral Aβ deposition is associated with reduced gait speed, muscle strength, and balance in older adults with cognitive impairment independent of WML load. However, Aβ deposition was not associated with functional mobility.
认知障碍和痴呆症的老年患者常存在身体机能受损（即步态减慢、肌肉无力和活动能力下降）。有证据表明，脑小血管疾病，特别是脑白质病变（WML），与身体机能受损有关，但对于阿尔茨海默病病理学在身体结果中的具体作用，研究甚少。
本研究旨在探讨认知障碍患者大脑中β淀粉样蛋白（Aβ）沉积与身体机能之间的关系。
30 名参与者完成了 11C 匹兹堡复合物 B（PIB）正电子发射断层扫描（PET），使用标准化摄取值比（SUVR）来量化大脑的 Aβ 沉积情况。我们使用短体物理表现测试（SPPB）和计时起立行走测试（TUGT）来评估参与者的一般步速、下肢肌肉力量、平衡和功能移动能力。多线性回归分析检验了 Aβ与身体机能各项指标之间的关联，调整了年龄、体重指数和 WML 负荷。
大脑 PIB SUVR 与一般步速（β=-0.52，p=0.01）和 SPPB 表现（β=-0.47，p=0.02）显著相关，表明 Aβ 沉积增加与这两个指标的表现降低有关。大脑 PIB SUVR 与 TUGT 表现无显著相关性（β=0.32，p=0.08）。
在认知障碍的老年患者中，大脑 Aβ 沉积与步行速度、肌肉力量和平衡下降有关，而与功能移动能力无关，且与 WML 负荷无关。
