Lower odor identification in subjective cognitive decline: a meta-analysis.

IF 4.4 Q1 CLINICAL NEUROLOGY

Alzheimer''s and Dementia: Diagnosis, Assessment and Disease Monitoring Pub Date : 2025-08-17 eCollection Date: 2025-07-01 DOI:10.1002/dad2.70168

Benoît Jobin, Zigrand Coline, Johannes Frasnelli, Benjamin Boller, Mark W Albers

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引用次数: 0

Abstract

Introduction: Odor identification correlates with Alzheimer's disease (AD) biomarkers, and its decline may emerge before measurable cognitive deficits - as early as the subjective cognitive decline (SCD) stage. We aimed to compare odor identification between SCD and cognitively normal (CN) stages.

Methods: A systematic search of four databases identified studies assessing olfactory identification and cognitive screening in individuals aged 50+. A random-effects meta-analysis was performed on 11 studies (660 SCD, 574 CN).

Results: Individuals with SCD exhibited lower olfactory identification scores compared to CN participants (SMD = -0.67, 95% CI [-1.31, -0.03], p = 0.04). Meta-regression revealed a negative association (β = -1.79, p = 0.02) between cognitive and olfactory differences; lower olfactory identification scores in SCD occurred despite minimal cognitive differences across groups.

Discussion: Odor identification is lower in pre-mild cognitive impairment individuals reporting SCD. Olfactory decline may emerge prior to measurable general cognitive decline, supporting its role as a screen for AD.

Highlights: Individuals with SCD exhibit lower odor identification scores.Olfactory identification may serve as an early marker of neurodegeneration in preclinical AD.Heterogeneity highlights the need for multimodal biomarker approaches.

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主观认知衰退中较低的气味识别：一项荟萃分析。

气味识别与阿尔茨海默病（AD）生物标志物相关，其下降可能在可测量的认知缺陷之前出现-早在主观认知衰退（SCD）阶段。我们的目的是比较SCD和认知正常（CN）阶段的气味识别。方法：系统检索了四个数据库，确定了评估50岁以上个体嗅觉识别和认知筛查的研究。对11项研究（660 SCD, 574 CN）进行随机效应荟萃分析。结果：SCD个体的嗅觉识别得分低于CN参与者（SMD = -0.67, 95% CI [-1.31, -0.03], p = 0.04）。元回归结果显示，认知差异与嗅觉差异呈负相关（β = -1.79, p = 0.02）；尽管组间认知差异很小，但SCD患者的嗅觉识别得分较低。讨论：气味识别在轻度认知障碍前报告SCD的个体中较低。嗅觉衰退可能出现在可测量的一般认知衰退之前，支持其作为AD筛查的作用。亮点：SCD个体表现出较低的气味识别分数。嗅觉识别可以作为临床前阿尔茨海默病神经变性的早期标志。异质性突出了对多模式生物标志物方法的需求。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Alzheimer''s and Dementia: Diagnosis, Assessment and Disease Monitoring Medicine-Psychiatry and Mental Health

CiteScore

7.80

自引率

7.50%

发文量

101

审稿时长

8 weeks

期刊介绍： Alzheimer''s & Dementia: Diagnosis, Assessment & Disease Monitoring (DADM) is an open access, peer-reviewed, journal from the Alzheimer''s Association® that will publish new research that reports the discovery, development and validation of instruments, technologies, algorithms, and innovative processes. Papers will cover a range of topics interested in the early and accurate detection of individuals with memory complaints and/or among asymptomatic individuals at elevated risk for various forms of memory disorders. The expectation for published papers will be to translate fundamental knowledge about the neurobiology of the disease into practical reports that describe both the conceptual and methodological aspects of the submitted scientific inquiry. Published topics will explore the development of biomarkers, surrogate markers, and conceptual/methodological challenges. Publication priority will be given to papers that 1) describe putative surrogate markers that accurately track disease progression, 2) biomarkers that fulfill international regulatory requirements, 3) reports from large, well-characterized population-based cohorts that comprise the heterogeneity and diversity of asymptomatic individuals and 4) algorithmic development that considers multi-marker arrays (e.g., integrated-omics, genetics, biofluids, imaging, etc.) and advanced computational analytics and technologies.