Department of Neurosciences, University of California, San Diego, CA, USA.
Alzheimer Dis Assoc Disord. 2012 Jul-Sep;26(3):260-6. doi: 10.1097/WAD.0b013e3182389a9c.
Increased susceptibility of the aging brain to both chronic stress and incipient dementia-related neuropathology may accelerate cognitive decline. We investigated associations between chronic stress and diagnostic change in 62 individuals (mean age, 78.7 y) participating in an Alzheimer disease research center longitudinal study. The subjects, diagnosed at baseline as cognitively normal (CN) or with mild cognitive impairment (MCI), were followed for an average of 2.5 years. Senior neurologists, blind to detailed measures of stress and cognition, assigned diagnoses annually. Logistic regression analyses assessed the accuracy with which measures of stress (event-based ratings, cortisol levels) predicted the conversion to MCI and dementia. Eleven individuals with MCI at baseline received a dementia diagnosis during follow-up. Sixteen converted from cognitively normal to MCI. Prolonged, highly stressful experiences were associated with conversion from MCI to dementia. The cortisol awakening response, with age and education, was associated with a diagnostic change to MCI. Cortisol measures were not associated with the progression from MCI to dementia, and there was no association between stressful experiences and the change to MCI. Mechanisms associated with the transition from normal cognition to MCI may differ from those associated with a diagnostic change to dementia. These findings could facilitate the identification of interventional strategies to reduce the risk of decline at different stages of susceptibility.
衰老大脑对慢性应激和早期与痴呆相关的神经病理学的敏感性增加，可能会加速认知能力下降。我们研究了慢性应激与 62 名参与者（平均年龄 78.7 岁）在阿尔茨海默病研究中心纵向研究中的诊断变化之间的关联。这些受试者在基线时被诊断为认知正常（CN）或轻度认知障碍（MCI），平均随访 2.5 年。高级神经科医生对压力和认知的详细测量结果不知情，每年分配诊断。逻辑回归分析评估了应激测量（基于事件的评分、皮质醇水平）预测向 MCI 和痴呆转化的准确性。11 名基线时患有 MCI 的患者在随访期间被诊断为痴呆。16 名从认知正常转为 MCI。长期、高度应激的经历与从中度认知障碍转为痴呆有关。皮质醇觉醒反应与年龄和教育程度相关，与 MCI 的诊断变化相关。皮质醇测量与从中度认知障碍进展为痴呆无关，应激经历与向 MCI 的变化无关。从正常认知到 MCI 的过渡所涉及的机制可能与向痴呆的诊断变化不同。这些发现可以促进确定在不同易感性阶段降低下降风险的干预策略。
