Roalf David R, Moberg Madelyn J, Turetsky Bruce I, Brennan Laura, Kabadi Sushila, Wolk David A, Moberg Paul J
Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA.
Department of Neurology, Drexel University School of Medicine, Philadelphia, Pennsylvania, USA.
J Neurol Neurosurg Psychiatry. 2017 Mar;88(3):226-232. doi: 10.1136/jnnp-2016-314638. Epub 2016 Dec 30.
The connection between Alzheimer's disease (AD) and olfactory deficits is well documented and further, alterations in olfactory functioning may signal declines in functions associated with dementia. The aim of the present comprehensive meta-analysis was to investigate the nature of olfactory deficits in mild cognitive impairment (MCI).
Articles were identified through computerised literature search from inception to 30 June 2016 using PubMed, MEDLINE and PsychInfo databases. In order to control for differences in sample size during effect size computation, studies were weighted according to their inverse variance estimates.
31 articles (62 effects) were identified, which included 1993 MCI patients and 2861 healthy older adults (HOA). Included studies contrasted odour identification, discrimination, detection threshold and/or memory between cases and controls. Moderate to large and heterogeneous effects were seen for olfactory deficits in MCI relative to HOA (d=-0.76, 95% CI -0.87<δ<-0.64). Moderator analysis revealed that tests of odour identification yielded larger effect sizes than those of odour detection threshold or memory. In addition, a potential interaction between age and sex was observed, with male patients carrying a larger burden of olfactory deficit and older female patients performing better on olfactory tests.
Olfactory deficits are present and robust in MCI. Odour identification is most impaired in MCI, which parallels the most prominent sensory deficit seen in AD. As such, a simple-to-administer test of odour identification warrants inclusion in the screening of individuals at risk for developing AD.
阿尔茨海默病（AD）与嗅觉缺陷之间的联系已有充分记录，此外，嗅觉功能的改变可能预示着与痴呆相关的功能衰退。本项综合荟萃分析的目的是研究轻度认知障碍（MCI）中嗅觉缺陷的本质。
通过计算机文献检索，利用PubMed、MEDLINE和PsychInfo数据库，检索从数据库建立至2016年6月30日的文章。为了在计算效应量时控制样本量的差异，根据研究的逆方差估计对研究进行加权。
共纳入31篇文章（62个效应），包括1993例MCI患者和2861名健康老年人（HOA）。纳入的研究对比了病例组和对照组之间的气味识别、辨别、检测阈值和/或记忆。与HOA相比，MCI患者的嗅觉缺陷呈现中度到高度且异质性的效应（d=-0.76，95%CI -0.87<δ<-0.64）。调节因素分析显示，气味识别测试产生的效应量大于气味检测阈值或记忆测试。此外，观察到年龄和性别之间存在潜在的相互作用，男性患者的嗅觉缺陷负担更大，而老年女性患者在嗅觉测试中的表现更好。
MCI患者存在明显且稳定的嗅觉缺陷。MCI患者中气味识别受损最为严重，这与AD中最突出的感觉缺陷相似。因此，一种易于实施的气味识别测试值得纳入AD高危个体的筛查中。
