Benyahia Steven A, Kahlon Sunny, Rijnhart Judith, Bishnoi Ram
Anesthesiology, USF (University of South Florida) Morsani College of Medicine, Tampa, USA.
Internal Medicine, USF (University of South Florida) Morsani College of Medicine, Tampa, USA.
Cureus. 2024 Sep 19;16(9):e69716. doi: 10.7759/cureus.69716. eCollection 2024 Sep.
Background Alzheimer's disease (AD) is a form of dementia, marked by amyloid-β plaques, neurofibrillary tangles, and neuronal loss. The amyloid burden has been associated with cognitive impairment and depression, suggesting a potential link between these conditions. Objective This study investigates the relationships between amyloid burden, cognitive impairment, and depression in the preclinical stages of AD. Methods Data from the Anti-Amyloid Treatment in Asymptomatic Alzheimer's (A4) study, involving 4486 cognitively unimpaired individuals aged 65-85, was analyzed. The amyloid burden was assessed using positron emission tomography (PET) standardized uptake value ratio (SUVR), cognitive function via cognitive function index (CFI) and tests, and depression via the short-form geriatric depression scale. Mediation analyses, adjusted for age, sex, and education, were employed to measure the impact of amyloid deposition on depression into direct and cognition-mediated indirect effects. Results No significant direct correlation between amyloid burden and depression was found (p=0.2935). Significant indirect effects were observed in cognition measures: CFI (0.3203, 95% CI: (0.2382, 0.4010)), digit symbol substitution test (0.0401, 95% CI: (0.0180, 0.0683)), and immediate recall (0.0169, 95% CI: (0.0014, 0.0354)). However, free and cued selective reminding (0.0056, 95% CI: (-0.0078, 0.0268)) and delayed recall (0.0105, 95% CI: (-0.0009, 0.0259)) showed no significant indirect effects. Conclusions The findings indicate significant mediation by CFI, digit symbol substitution test, and immediate recall in the relationship between amyloid burden and depression while free and cued selective reminding and delayed recall showed no significant mediation. These results underscore the importance of further research using longitudinal data and a broader range of confounders to fully understand cognition's mediating role.
阿尔茨海默病（AD）是痴呆症的一种形式，其特征为β淀粉样蛋白斑块、神经原纤维缠结和神经元丢失。淀粉样蛋白负荷与认知障碍和抑郁有关，提示这些病症之间可能存在联系。目的：本研究调查AD临床前期淀粉样蛋白负荷、认知障碍和抑郁之间的关系。方法：分析来自无症状阿尔茨海默病抗淀粉样蛋白治疗（A4）研究的数据，该研究涉及4486名年龄在65 - 85岁认知未受损的个体。使用正电子发射断层扫描（PET）标准化摄取值比率（SUVR）评估淀粉样蛋白负荷，通过认知功能指数（CFI）和测试评估认知功能，通过简易老年抑郁量表评估抑郁。采用经年龄、性别和教育程度调整的中介分析，以测量淀粉样蛋白沉积对抑郁的影响，分为直接影响和认知介导的间接影响。结果：未发现淀粉样蛋白负荷与抑郁之间存在显著直接相关性（p = 0.2935）。在认知测量中观察到显著的间接影响：CFI（0.3203，95%置信区间：（0.2382，0.4010））、数字符号替换测试（0.0401，95%置信区间：（0.0180，0.0683））和即时回忆（0.0169，95%置信区间：（0.0014，0.0354））。然而，自由和线索选择性回忆（0.0056，95%置信区间：（-0.0078，0.0268））和延迟回忆（0.0105，95%置信区间：（-0.0009，0.0259））未显示出显著的间接影响。结论：研究结果表明，CFI、数字符号替换测试和即时回忆在淀粉样蛋白负荷与抑郁之间的关系中具有显著中介作用，而自由和线索选择性回忆以及延迟回忆未显示出显著中介作用。这些结果强调了使用纵向数据和更广泛的混杂因素进行进一步研究以充分理解认知中介作用的重要性。
