Kida Jiro, Nemoto Kiyotaka, Ikejima Chiaki, Bun Shogyoku, Kakuma Tatsuyuki, Mizukami Katsuyoshi, Asada Takashi
Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan.
Department of Psychiatry, Tokyo Adachi Hospital, Tokyo, Japan.
J Alzheimers Dis. 2016;51(2):405-15. doi: 10.3233/JAD-150603.
While longitudinal studies have investigated the relationships between mild cognitive impairment (MCI) subtypes and dementia subtypes, the results have been contradictory. In addition, some research shows that depression accompanied by MCI might increase the risk of Alzheimer's disease (AD).
The aim of this study is to longitudinally investigate the relationships between MCI subtypes and dementia subtypes, with special attention to the effect of comorbid depressive symptoms in a Japanese rural community.
Non-demented participants (n = 802) completed a baseline and follow-up study. Outcomes were conversion to dementia especially AD, MCI, or no conversion. A complementary log-log analysis was conducted to investigate the risk of dementia and AD in amnestic MCI (aMCI) compared to nonamnestic MCI (naMCI) groups. The impact of depressive symptoms on the transition from MCI to AD and from cognitively normal to MCI or AD was also analyzed.
The risk of developing dementia, in particular AD, for the aMCI group was significantly higher than that for the naMCI group. In the aMCI group, the presence of depressive symptoms increased the risk of developing AD, but depressive symptoms in the naMCI group did not. In the cognitively normal group, the presence of depressive symptoms increased the risk of aMCI but not naMCI or AD.
MCI subtyping could be useful in finding a prodrome for dementia and in particular for AD. The differing impacts of depressive symptoms on the development of AD suggest that the relationship between depressive symptoms and cognitive impairment could differ in aMCI and naMCI patients.
虽然纵向研究已经调查了轻度认知障碍（MCI）亚型与痴呆症亚型之间的关系，但结果相互矛盾。此外，一些研究表明，伴有MCI的抑郁症可能会增加患阿尔茨海默病（AD）的风险。
本研究旨在纵向调查MCI亚型与痴呆症亚型之间的关系，特别关注日本农村社区中合并抑郁症状的影响。
非痴呆参与者（n = 802）完成了基线和随访研究。结局为转化为痴呆症，尤其是AD、MCI或未转化。进行了互补对数-对数分析，以研究遗忘型MCI（aMCI）组与非遗忘型MCI（naMCI）组相比患痴呆症和AD的风险。还分析了抑郁症状对从MCI转化为AD以及从认知正常转化为MCI或AD的影响。
aMCI组患痴呆症，尤其是AD的风险显著高于naMCI组。在aMCI组中，抑郁症状的存在增加了患AD的风险，但naMCI组中的抑郁症状则没有。在认知正常组中，抑郁症状的存在增加了患aMCI的风险，但未增加患naMCI或AD的风险。
MCI亚型分类可能有助于发现痴呆症，尤其是AD的前驱症状。抑郁症状对AD发展的不同影响表明，抑郁症状与认知障碍之间的关系在aMCI和naMCI患者中可能有所不同。
