Olfactory Identification as a Biomarker for Cognitive Impairment: Insights from Healthy Aging, Subjective Cognitive Decline, and Mild Cognitive Impairment

<b>Introduction</b>: This study aims to investigate the relationship between olfactory identification (OI) and cognitive impairment by examining OI abilities across various stages of cognitive deterioration. <b>Methods</b>: A total of 264 participants were divided into three groups based on cognitive status: cognitively healthy, subjective cognitive, and mild cognitive impairment. All participants were assessed using the Sniffin' Sticks Olfactory Identification test and a comprehensive neuropsychological test battery. <b>Results</b>: Our results highlight the main effects of age and cognitive status on OI scores. Regarding cognitive abilities, OI is associated with measures of short-term memory, long-term, working memory, and selective attention. Finally, logistic regression models showed that OI is a significant predictor for discriminating SCD from CH, MCI from CH, and MCI from SCD. <b>Discussion</b>: These findings suggest the addition of olfactory identification measures in neuropsychological assessments could improve the early detection of individuals at risk for cognitive impairment.