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Shrestha S, Zhu X, Sullivan KJ, Blackshear C, Deal JA, Sharrett AR, Kamath V, Schneider ALC, Jack CR, Huang J, Palta P, Reid RI, Knopman DS, Gottesman RF, Chen H, Windham BG, Griswold ME, Mosley TH. Association of Olfaction and Microstructural Integrity of Brain Tissue in Community-Dwelling Adults: Atherosclerosis Risk in Communities Neurocognitive Study. Neurology 2023; 101:e1328-e1340. [PMID: 37541841 PMCID: PMC10558165 DOI: 10.1212/wnl.0000000000207636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 05/30/2023] [Indexed: 08/06/2023] Open
Abstract
BACKGROUND AND OBJECTIVES Research on olfaction and brain neuropathology may help understand brain regions associated with normal olfaction and dementia pathophysiology. To identify early regional brain structures affected in poor olfaction, we examined cross-sectional associations of microstructural integrity of the brain with olfaction in the Atherosclerosis Risk in Communities Neurocognitive Study. METHODS Participants were selected from a prospective cohort study of community-dwelling adults; selection criteria included the following: evidence of cognitive impairment, participation in a previous MRI study, and a random sample of cognitively normal participants. Microstructural integrity was measured by 2 diffusion tensor imaging (DTI) measures, fractional anisotropy (FA) and mean diffusivity (MD), and olfaction by a 12-item odor identification test at the same visit. Higher FA and MD values indicate better and worse microstructural integrity, respectively, and higher odor identification scores indicate better olfaction. We used brain region-specific linear regression models to examine associations between DTI measures and olfaction, adjusting for potential confounders. RESULTS Among 1,418 participants (mean age 76 ± 5 years, 41% male, 21% Black race, 59% with normal cognition), the mean olfaction score was 9 ± 2.3. Relevant to olfaction, higher MD in the medial temporal lobe (MTL) regions, namely the hippocampus (β -0.79 [95% CI -0.94 to -0.65] units lower olfaction score per 1 SD higher MD), amygdala, entorhinal area, and some white matter (WM) tracts connecting to these regions, was associated with olfaction. We also observed associations with MD and WM FA in multiple atlas regions that were not previously implicated in olfaction. The associations between MD and olfaction were particularly stronger in the MTL regions among individuals with mild cognitive impairment (MCI) compared with those with normal cognition (e.g., βhippocampus -0.75 [95% CI -1.02 to -0.49] and -0.44 [95% CI -0.63 to -0.26] for MCI and normal cognition, respectively, p interaction = 0.004). DISCUSSION Neuronal microstructural integrity in multiple brain regions, particularly the MTL (the regions known to be affected in early Alzheimer disease), is associated with odor identification ability. Differential associations in the MTL regions among cognitively normal individuals compared with those with MCI may reflect the earlier vs later effects of the dementia pathogenesis. It is likely that some of the associated regions may not have any functional relevance to olfaction.
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Affiliation(s)
- Srishti Shrestha
- From the The Memory Impairment and Neurodegenerative Dementia (MIND) Center (S.S., X.Z., K.J.S., C.B., J.H., B.G.W., M.E.G., T.H.M.), University of Mississippi Medical Center, Jackson; Department of Epidemiology (J.A.D., A.R.S.), Johns Hopkins University Bloomberg School of Public Health; Department of Psychiatry and Behavioral Sciences (V.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Neurology (A.L.C.S.), and Department of Biostatistics, Epidemiology, and Informatics (A.L.C.S.), University of Pennsylvania Perelman School of Medicine, Philadelphia; Department of Radiology (C.R.J., R.I.R.), Mayo Clinic, Rochester, MN; Department of Neurology (J.H.), University of Mississippi Medical Center, Jackson; Department of Neurology (P.P.), University of North Carolina at Chapel Hill; Department of Neurology (D.S.K.), Mayo Clinic, Rochester, MN; Stroke Branch (R.F.G.), National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD; and Department of Epidemiology and Biostatistics (H.C.), Michigan State University, East Lansing.
| | - Xiaoqian Zhu
- From the The Memory Impairment and Neurodegenerative Dementia (MIND) Center (S.S., X.Z., K.J.S., C.B., J.H., B.G.W., M.E.G., T.H.M.), University of Mississippi Medical Center, Jackson; Department of Epidemiology (J.A.D., A.R.S.), Johns Hopkins University Bloomberg School of Public Health; Department of Psychiatry and Behavioral Sciences (V.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Neurology (A.L.C.S.), and Department of Biostatistics, Epidemiology, and Informatics (A.L.C.S.), University of Pennsylvania Perelman School of Medicine, Philadelphia; Department of Radiology (C.R.J., R.I.R.), Mayo Clinic, Rochester, MN; Department of Neurology (J.H.), University of Mississippi Medical Center, Jackson; Department of Neurology (P.P.), University of North Carolina at Chapel Hill; Department of Neurology (D.S.K.), Mayo Clinic, Rochester, MN; Stroke Branch (R.F.G.), National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD; and Department of Epidemiology and Biostatistics (H.C.), Michigan State University, East Lansing
| | - Kevin J Sullivan
- From the The Memory Impairment and Neurodegenerative Dementia (MIND) Center (S.S., X.Z., K.J.S., C.B., J.H., B.G.W., M.E.G., T.H.M.), University of Mississippi Medical Center, Jackson; Department of Epidemiology (J.A.D., A.R.S.), Johns Hopkins University Bloomberg School of Public Health; Department of Psychiatry and Behavioral Sciences (V.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Neurology (A.L.C.S.), and Department of Biostatistics, Epidemiology, and Informatics (A.L.C.S.), University of Pennsylvania Perelman School of Medicine, Philadelphia; Department of Radiology (C.R.J., R.I.R.), Mayo Clinic, Rochester, MN; Department of Neurology (J.H.), University of Mississippi Medical Center, Jackson; Department of Neurology (P.P.), University of North Carolina at Chapel Hill; Department of Neurology (D.S.K.), Mayo Clinic, Rochester, MN; Stroke Branch (R.F.G.), National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD; and Department of Epidemiology and Biostatistics (H.C.), Michigan State University, East Lansing
| | - Chad Blackshear
- From the The Memory Impairment and Neurodegenerative Dementia (MIND) Center (S.S., X.Z., K.J.S., C.B., J.H., B.G.W., M.E.G., T.H.M.), University of Mississippi Medical Center, Jackson; Department of Epidemiology (J.A.D., A.R.S.), Johns Hopkins University Bloomberg School of Public Health; Department of Psychiatry and Behavioral Sciences (V.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Neurology (A.L.C.S.), and Department of Biostatistics, Epidemiology, and Informatics (A.L.C.S.), University of Pennsylvania Perelman School of Medicine, Philadelphia; Department of Radiology (C.R.J., R.I.R.), Mayo Clinic, Rochester, MN; Department of Neurology (J.H.), University of Mississippi Medical Center, Jackson; Department of Neurology (P.P.), University of North Carolina at Chapel Hill; Department of Neurology (D.S.K.), Mayo Clinic, Rochester, MN; Stroke Branch (R.F.G.), National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD; and Department of Epidemiology and Biostatistics (H.C.), Michigan State University, East Lansing
| | - Jennifer A Deal
- From the The Memory Impairment and Neurodegenerative Dementia (MIND) Center (S.S., X.Z., K.J.S., C.B., J.H., B.G.W., M.E.G., T.H.M.), University of Mississippi Medical Center, Jackson; Department of Epidemiology (J.A.D., A.R.S.), Johns Hopkins University Bloomberg School of Public Health; Department of Psychiatry and Behavioral Sciences (V.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Neurology (A.L.C.S.), and Department of Biostatistics, Epidemiology, and Informatics (A.L.C.S.), University of Pennsylvania Perelman School of Medicine, Philadelphia; Department of Radiology (C.R.J., R.I.R.), Mayo Clinic, Rochester, MN; Department of Neurology (J.H.), University of Mississippi Medical Center, Jackson; Department of Neurology (P.P.), University of North Carolina at Chapel Hill; Department of Neurology (D.S.K.), Mayo Clinic, Rochester, MN; Stroke Branch (R.F.G.), National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD; and Department of Epidemiology and Biostatistics (H.C.), Michigan State University, East Lansing
| | - A Richey Sharrett
- From the The Memory Impairment and Neurodegenerative Dementia (MIND) Center (S.S., X.Z., K.J.S., C.B., J.H., B.G.W., M.E.G., T.H.M.), University of Mississippi Medical Center, Jackson; Department of Epidemiology (J.A.D., A.R.S.), Johns Hopkins University Bloomberg School of Public Health; Department of Psychiatry and Behavioral Sciences (V.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Neurology (A.L.C.S.), and Department of Biostatistics, Epidemiology, and Informatics (A.L.C.S.), University of Pennsylvania Perelman School of Medicine, Philadelphia; Department of Radiology (C.R.J., R.I.R.), Mayo Clinic, Rochester, MN; Department of Neurology (J.H.), University of Mississippi Medical Center, Jackson; Department of Neurology (P.P.), University of North Carolina at Chapel Hill; Department of Neurology (D.S.K.), Mayo Clinic, Rochester, MN; Stroke Branch (R.F.G.), National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD; and Department of Epidemiology and Biostatistics (H.C.), Michigan State University, East Lansing
| | - Vidyulata Kamath
- From the The Memory Impairment and Neurodegenerative Dementia (MIND) Center (S.S., X.Z., K.J.S., C.B., J.H., B.G.W., M.E.G., T.H.M.), University of Mississippi Medical Center, Jackson; Department of Epidemiology (J.A.D., A.R.S.), Johns Hopkins University Bloomberg School of Public Health; Department of Psychiatry and Behavioral Sciences (V.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Neurology (A.L.C.S.), and Department of Biostatistics, Epidemiology, and Informatics (A.L.C.S.), University of Pennsylvania Perelman School of Medicine, Philadelphia; Department of Radiology (C.R.J., R.I.R.), Mayo Clinic, Rochester, MN; Department of Neurology (J.H.), University of Mississippi Medical Center, Jackson; Department of Neurology (P.P.), University of North Carolina at Chapel Hill; Department of Neurology (D.S.K.), Mayo Clinic, Rochester, MN; Stroke Branch (R.F.G.), National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD; and Department of Epidemiology and Biostatistics (H.C.), Michigan State University, East Lansing
| | - Andrea L C Schneider
- From the The Memory Impairment and Neurodegenerative Dementia (MIND) Center (S.S., X.Z., K.J.S., C.B., J.H., B.G.W., M.E.G., T.H.M.), University of Mississippi Medical Center, Jackson; Department of Epidemiology (J.A.D., A.R.S.), Johns Hopkins University Bloomberg School of Public Health; Department of Psychiatry and Behavioral Sciences (V.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Neurology (A.L.C.S.), and Department of Biostatistics, Epidemiology, and Informatics (A.L.C.S.), University of Pennsylvania Perelman School of Medicine, Philadelphia; Department of Radiology (C.R.J., R.I.R.), Mayo Clinic, Rochester, MN; Department of Neurology (J.H.), University of Mississippi Medical Center, Jackson; Department of Neurology (P.P.), University of North Carolina at Chapel Hill; Department of Neurology (D.S.K.), Mayo Clinic, Rochester, MN; Stroke Branch (R.F.G.), National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD; and Department of Epidemiology and Biostatistics (H.C.), Michigan State University, East Lansing
| | - Clifford R Jack
- From the The Memory Impairment and Neurodegenerative Dementia (MIND) Center (S.S., X.Z., K.J.S., C.B., J.H., B.G.W., M.E.G., T.H.M.), University of Mississippi Medical Center, Jackson; Department of Epidemiology (J.A.D., A.R.S.), Johns Hopkins University Bloomberg School of Public Health; Department of Psychiatry and Behavioral Sciences (V.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Neurology (A.L.C.S.), and Department of Biostatistics, Epidemiology, and Informatics (A.L.C.S.), University of Pennsylvania Perelman School of Medicine, Philadelphia; Department of Radiology (C.R.J., R.I.R.), Mayo Clinic, Rochester, MN; Department of Neurology (J.H.), University of Mississippi Medical Center, Jackson; Department of Neurology (P.P.), University of North Carolina at Chapel Hill; Department of Neurology (D.S.K.), Mayo Clinic, Rochester, MN; Stroke Branch (R.F.G.), National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD; and Department of Epidemiology and Biostatistics (H.C.), Michigan State University, East Lansing
| | - Juebin Huang
- From the The Memory Impairment and Neurodegenerative Dementia (MIND) Center (S.S., X.Z., K.J.S., C.B., J.H., B.G.W., M.E.G., T.H.M.), University of Mississippi Medical Center, Jackson; Department of Epidemiology (J.A.D., A.R.S.), Johns Hopkins University Bloomberg School of Public Health; Department of Psychiatry and Behavioral Sciences (V.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Neurology (A.L.C.S.), and Department of Biostatistics, Epidemiology, and Informatics (A.L.C.S.), University of Pennsylvania Perelman School of Medicine, Philadelphia; Department of Radiology (C.R.J., R.I.R.), Mayo Clinic, Rochester, MN; Department of Neurology (J.H.), University of Mississippi Medical Center, Jackson; Department of Neurology (P.P.), University of North Carolina at Chapel Hill; Department of Neurology (D.S.K.), Mayo Clinic, Rochester, MN; Stroke Branch (R.F.G.), National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD; and Department of Epidemiology and Biostatistics (H.C.), Michigan State University, East Lansing
| | - Priya Palta
- From the The Memory Impairment and Neurodegenerative Dementia (MIND) Center (S.S., X.Z., K.J.S., C.B., J.H., B.G.W., M.E.G., T.H.M.), University of Mississippi Medical Center, Jackson; Department of Epidemiology (J.A.D., A.R.S.), Johns Hopkins University Bloomberg School of Public Health; Department of Psychiatry and Behavioral Sciences (V.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Neurology (A.L.C.S.), and Department of Biostatistics, Epidemiology, and Informatics (A.L.C.S.), University of Pennsylvania Perelman School of Medicine, Philadelphia; Department of Radiology (C.R.J., R.I.R.), Mayo Clinic, Rochester, MN; Department of Neurology (J.H.), University of Mississippi Medical Center, Jackson; Department of Neurology (P.P.), University of North Carolina at Chapel Hill; Department of Neurology (D.S.K.), Mayo Clinic, Rochester, MN; Stroke Branch (R.F.G.), National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD; and Department of Epidemiology and Biostatistics (H.C.), Michigan State University, East Lansing
| | - Robert I Reid
- From the The Memory Impairment and Neurodegenerative Dementia (MIND) Center (S.S., X.Z., K.J.S., C.B., J.H., B.G.W., M.E.G., T.H.M.), University of Mississippi Medical Center, Jackson; Department of Epidemiology (J.A.D., A.R.S.), Johns Hopkins University Bloomberg School of Public Health; Department of Psychiatry and Behavioral Sciences (V.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Neurology (A.L.C.S.), and Department of Biostatistics, Epidemiology, and Informatics (A.L.C.S.), University of Pennsylvania Perelman School of Medicine, Philadelphia; Department of Radiology (C.R.J., R.I.R.), Mayo Clinic, Rochester, MN; Department of Neurology (J.H.), University of Mississippi Medical Center, Jackson; Department of Neurology (P.P.), University of North Carolina at Chapel Hill; Department of Neurology (D.S.K.), Mayo Clinic, Rochester, MN; Stroke Branch (R.F.G.), National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD; and Department of Epidemiology and Biostatistics (H.C.), Michigan State University, East Lansing
| | - David S Knopman
- From the The Memory Impairment and Neurodegenerative Dementia (MIND) Center (S.S., X.Z., K.J.S., C.B., J.H., B.G.W., M.E.G., T.H.M.), University of Mississippi Medical Center, Jackson; Department of Epidemiology (J.A.D., A.R.S.), Johns Hopkins University Bloomberg School of Public Health; Department of Psychiatry and Behavioral Sciences (V.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Neurology (A.L.C.S.), and Department of Biostatistics, Epidemiology, and Informatics (A.L.C.S.), University of Pennsylvania Perelman School of Medicine, Philadelphia; Department of Radiology (C.R.J., R.I.R.), Mayo Clinic, Rochester, MN; Department of Neurology (J.H.), University of Mississippi Medical Center, Jackson; Department of Neurology (P.P.), University of North Carolina at Chapel Hill; Department of Neurology (D.S.K.), Mayo Clinic, Rochester, MN; Stroke Branch (R.F.G.), National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD; and Department of Epidemiology and Biostatistics (H.C.), Michigan State University, East Lansing
| | - Rebecca F Gottesman
- From the The Memory Impairment and Neurodegenerative Dementia (MIND) Center (S.S., X.Z., K.J.S., C.B., J.H., B.G.W., M.E.G., T.H.M.), University of Mississippi Medical Center, Jackson; Department of Epidemiology (J.A.D., A.R.S.), Johns Hopkins University Bloomberg School of Public Health; Department of Psychiatry and Behavioral Sciences (V.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Neurology (A.L.C.S.), and Department of Biostatistics, Epidemiology, and Informatics (A.L.C.S.), University of Pennsylvania Perelman School of Medicine, Philadelphia; Department of Radiology (C.R.J., R.I.R.), Mayo Clinic, Rochester, MN; Department of Neurology (J.H.), University of Mississippi Medical Center, Jackson; Department of Neurology (P.P.), University of North Carolina at Chapel Hill; Department of Neurology (D.S.K.), Mayo Clinic, Rochester, MN; Stroke Branch (R.F.G.), National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD; and Department of Epidemiology and Biostatistics (H.C.), Michigan State University, East Lansing
| | - Honglei Chen
- From the The Memory Impairment and Neurodegenerative Dementia (MIND) Center (S.S., X.Z., K.J.S., C.B., J.H., B.G.W., M.E.G., T.H.M.), University of Mississippi Medical Center, Jackson; Department of Epidemiology (J.A.D., A.R.S.), Johns Hopkins University Bloomberg School of Public Health; Department of Psychiatry and Behavioral Sciences (V.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Neurology (A.L.C.S.), and Department of Biostatistics, Epidemiology, and Informatics (A.L.C.S.), University of Pennsylvania Perelman School of Medicine, Philadelphia; Department of Radiology (C.R.J., R.I.R.), Mayo Clinic, Rochester, MN; Department of Neurology (J.H.), University of Mississippi Medical Center, Jackson; Department of Neurology (P.P.), University of North Carolina at Chapel Hill; Department of Neurology (D.S.K.), Mayo Clinic, Rochester, MN; Stroke Branch (R.F.G.), National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD; and Department of Epidemiology and Biostatistics (H.C.), Michigan State University, East Lansing
| | - B Gwen Windham
- From the The Memory Impairment and Neurodegenerative Dementia (MIND) Center (S.S., X.Z., K.J.S., C.B., J.H., B.G.W., M.E.G., T.H.M.), University of Mississippi Medical Center, Jackson; Department of Epidemiology (J.A.D., A.R.S.), Johns Hopkins University Bloomberg School of Public Health; Department of Psychiatry and Behavioral Sciences (V.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Neurology (A.L.C.S.), and Department of Biostatistics, Epidemiology, and Informatics (A.L.C.S.), University of Pennsylvania Perelman School of Medicine, Philadelphia; Department of Radiology (C.R.J., R.I.R.), Mayo Clinic, Rochester, MN; Department of Neurology (J.H.), University of Mississippi Medical Center, Jackson; Department of Neurology (P.P.), University of North Carolina at Chapel Hill; Department of Neurology (D.S.K.), Mayo Clinic, Rochester, MN; Stroke Branch (R.F.G.), National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD; and Department of Epidemiology and Biostatistics (H.C.), Michigan State University, East Lansing
| | - Michael E Griswold
- From the The Memory Impairment and Neurodegenerative Dementia (MIND) Center (S.S., X.Z., K.J.S., C.B., J.H., B.G.W., M.E.G., T.H.M.), University of Mississippi Medical Center, Jackson; Department of Epidemiology (J.A.D., A.R.S.), Johns Hopkins University Bloomberg School of Public Health; Department of Psychiatry and Behavioral Sciences (V.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Neurology (A.L.C.S.), and Department of Biostatistics, Epidemiology, and Informatics (A.L.C.S.), University of Pennsylvania Perelman School of Medicine, Philadelphia; Department of Radiology (C.R.J., R.I.R.), Mayo Clinic, Rochester, MN; Department of Neurology (J.H.), University of Mississippi Medical Center, Jackson; Department of Neurology (P.P.), University of North Carolina at Chapel Hill; Department of Neurology (D.S.K.), Mayo Clinic, Rochester, MN; Stroke Branch (R.F.G.), National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD; and Department of Epidemiology and Biostatistics (H.C.), Michigan State University, East Lansing
| | - Thomas H Mosley
- From the The Memory Impairment and Neurodegenerative Dementia (MIND) Center (S.S., X.Z., K.J.S., C.B., J.H., B.G.W., M.E.G., T.H.M.), University of Mississippi Medical Center, Jackson; Department of Epidemiology (J.A.D., A.R.S.), Johns Hopkins University Bloomberg School of Public Health; Department of Psychiatry and Behavioral Sciences (V.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Neurology (A.L.C.S.), and Department of Biostatistics, Epidemiology, and Informatics (A.L.C.S.), University of Pennsylvania Perelman School of Medicine, Philadelphia; Department of Radiology (C.R.J., R.I.R.), Mayo Clinic, Rochester, MN; Department of Neurology (J.H.), University of Mississippi Medical Center, Jackson; Department of Neurology (P.P.), University of North Carolina at Chapel Hill; Department of Neurology (D.S.K.), Mayo Clinic, Rochester, MN; Stroke Branch (R.F.G.), National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD; and Department of Epidemiology and Biostatistics (H.C.), Michigan State University, East Lansing
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Mi Y, Ma X, Du S, Du C, Li X, Tan H, Zhang J, Zhang Q, Shi W, Zhang G, Tian Y. Olfactory function changes and the predictive performance of the Chinese Smell Identification Test in patients with mild cognitive impairment and Alzheimer's disease. Front Aging Neurosci 2023; 15:1068708. [PMID: 36861124 PMCID: PMC9969891 DOI: 10.3389/fnagi.2023.1068708] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 01/16/2023] [Indexed: 02/16/2023] Open
Abstract
Objectives Olfactory disorder is one of the sensory features that reflects a decline in cognitive function. However, olfactory changes and the discernibility of smell testing in the aging population have yet to be fully elucidated. Therefore, this study aimed to examine the effectiveness of the Chinese Smell Identification Test (CSIT) in distinguishing individuals with cognitive decline from those with normal aging and to determine whether the patients with MCI and AD show changes in their olfactory identification abilities. Methods This cross-sectional study included eligible participants aged over 50 years between October 2019 and December 2021. The participants were divided into three groups: individuals with mild cognitive impairment (MCI), individuals with Alzheimer's disease (AD), and cognitively normal controls (NCs). All participants were assessed using neuropsychiatric scales, the Activity of Daily Living scale, and the 16-odor cognitive state test (CSIT) test. The test scores and the severity of olfactory impairment were also recorded for each participant. Results In total, 366 eligible participants were recruited, including 188 participants with MCI, 42 patients with AD, and 136 NCs. Patients with MCI achieved a mean CSIT score of 13.06 ± 2.05, while patients with AD achieved a mean score of 11.38 ± 3.25. These scores were significantly lower than those of the NC group (14.6 ± 1.57; P < 0.001). An analysis showed that 19.9% of NCs exhibited mild olfactory impairment, while 52.7% of patients with MCI and 69% of patients with AD exhibited mild to severe olfactory impairment. The CSIT score was positively correlated with the MoCA and MMSE scores. The CIST score and the severity of olfactory impairment were identified as robust indicators for MCI and AD, even after adjusting for age, gender, and level of education. Age and educational level were identified as two important confounding factors that influence cognitive function. However, no significant interactive effects were observed between these confounders and CIST scores in determining the risk of MCI. The area under the ROC curve (AUC) generated from the ROC analysis was 0.738 and 0.813 in distinguishing patients with MCI and patients with AD from NCs based on the CIST scores, respectively. The optimal cutoff for distinguishing MCI from NCs was 13, and for distinguishing AD from NCs was 11. The AUC for distinguishing AD from MCI was 0.62. Conclusions The olfactory identification function is frequently affected in patients with MCI and patients with AD. CSIT is a beneficial tool for the early screening of cognitive impairment among elderly patients with cognitive or memory issues.
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Affiliation(s)
- Yan Mi
- Department of Neurology, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China,Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China
| | - Xiaojuan Ma
- Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China,Clinical Medical Research Center, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China
| | - Shan Du
- Department of Neurology, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China,Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China
| | - Chengxue Du
- Department of Neurology, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China,Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China
| | - Xiaobo Li
- Department of Neurology, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China,Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China
| | - Huihui Tan
- Department of Neurology, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China,Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China
| | - Jie Zhang
- Department of Neurology, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China,Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China
| | - Qi Zhang
- Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China,Clinical Medical Research Center, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China
| | - Wenzhen Shi
- Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China,Clinical Medical Research Center, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China,Wenzhen Shi ✉
| | - Gejuan Zhang
- Department of Neurology, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China,Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China,Gejuan Zhang ✉
| | - Ye Tian
- Department of Neurology, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China,Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, The Affiliated Hospital of Northwest University, Xi'an No.3 Hospital, Xi'an, Shaanxi, China,*Correspondence: Ye Tian ✉
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