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Loughnane M, Tischler V, Khalid Saifeldeen R, Kontaris E. Aging and Olfactory Training: A Scoping Review. Innov Aging 2024; 8:igae044. [PMID: 38881614 PMCID: PMC11176978 DOI: 10.1093/geroni/igae044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Indexed: 06/18/2024] Open
Abstract
Background and Objectives Decreased olfactory function commonly occurs alongside the aging process. Research suggests olfactory training (OT) has the potential to improve olfactory and cognitive function in individuals with and without olfactory dysfunction. The degree to which these benefits extend into older age and among those with cognitive impairment (i.e., people with dementia and mild cognitive impairment) is less clear. The purpose of the current review was to investigate the extent to which OT affects olfactory function, cognition, and well-being among older people. Research Design and Methods A scoping review of the literature was conducted in PubMed, Embase, EbscoHost, and SCOPUS. Articles were considered eligible for original research studies with human populations, included adults aged 55 and older, performed any type of OT, and included a form of olfactory testing. The data from the included studies were synthesized and presented narratively. Results A total of 23 studies were included. The results suggest that OT provides multiple benefits to older adults, including those with cognitive impairment. Particularly, OT was associated with measurable changes in olfactory function, improved cognitive function, specifically semantic verbal fluency and working memory, reduced depressive symptoms, and protection from cognitive decline. Discussion and Implications The findings suggest that benefits from OT extend beyond changes in olfactory function and include improved cognitive function, amelioration of depressive symptoms, and protection from cognitive decline. Future research is needed across specific participant groups, including those with differentiated types of dementia, to investigate the olfactory and cognitive benefits of OT.
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Affiliation(s)
| | | | | | - Emily Kontaris
- Health and Well-Being Centre of Excellence, Givaudan UK Limited, Ashford, UK
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Kalam S, Numbers K, Lipnicki DM, Lam BCP, Brodaty H, Reppermund S. The combination of olfactory dysfunction and depression increases the risk of incident dementia in older adults. Int Psychogeriatr 2024; 36:130-141. [PMID: 37264675 DOI: 10.1017/s1041610223000480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
OBJECTIVES Olfactory dysfunction and depression are common in later life, and both have been presented as risk factors for dementia. Our purpose was to investigate the associations between these two risk factors and determine if they had an additive effect on dementia risk. DESIGN Olfactory function was assessed using the Brief Smell Identification Test (BSIT), and depression was classified using a combination of the 15-item Geriatric Depression Scale (GDS) score and current antidepressant use. Cross-sectional associations between depression and olfactory function were examined using correlations. Cox regression analyses were conducted to examine the longitudinal relationship between olfaction and depression and incident dementia across 12-years of follow-up. PARTICIPANTS Participants were 780 older adults (aged 70-90 years; 56.5% female) from the Sydney Memory and Ageing Study (MAS) without a diagnosis of dementia at baseline. RESULTS Partial correlation revealed a nonsignificant association between baseline depression and olfactory function after accounting for covariates (r = -.051, p = .173). Cox regression showed that depression at baseline (hazard ratio = 1.706, 95% CI 1.185-2.456, p = .004) and lower BSIT scores (HR = .845, 95%CI .789-.905, p < .001) were independently associated with a higher risk of incident dementia across 12 years. Entering both predictors together improved the overall predictive power of the model. CONCLUSIONS Lower olfactory identification scores and depressive symptoms predict incident dementia over 12 years. The use of BSIT scores and depression in conjunction provides a greater ability to predict dementia than either used alone. Assessment of olfactory function and depression screening may provide clinical utility in the early detection of dementia.
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Affiliation(s)
- Shafi Kalam
- Centre for Healthy Brain Ageing (CHeBA), Discipline of Psychiatry & Mental Health, School of Clinical Medicine, Faculty of Medicine & Health, University of New South Wales, Sydney, NSW, Australia
| | - Katya Numbers
- Centre for Healthy Brain Ageing (CHeBA), Discipline of Psychiatry & Mental Health, School of Clinical Medicine, Faculty of Medicine & Health, University of New South Wales, Sydney, NSW, Australia
| | - Darren M Lipnicki
- Centre for Healthy Brain Ageing (CHeBA), Discipline of Psychiatry & Mental Health, School of Clinical Medicine, Faculty of Medicine & Health, University of New South Wales, Sydney, NSW, Australia
| | - Ben C P Lam
- Centre for Healthy Brain Ageing (CHeBA), Discipline of Psychiatry & Mental Health, School of Clinical Medicine, Faculty of Medicine & Health, University of New South Wales, Sydney, NSW, Australia
- School of Psychology and Public Health, La Trobe University, VIC, Australia
| | - Henry Brodaty
- Centre for Healthy Brain Ageing (CHeBA), Discipline of Psychiatry & Mental Health, School of Clinical Medicine, Faculty of Medicine & Health, University of New South Wales, Sydney, NSW, Australia
| | - Simone Reppermund
- Centre for Healthy Brain Ageing (CHeBA), Discipline of Psychiatry & Mental Health, School of Clinical Medicine, Faculty of Medicine & Health, University of New South Wales, Sydney, NSW, Australia
- Department of Developmental Disability Neuropsychiatry (3DN), Discipline of Psychiatry & Mental Health, School of Clinical Medicine, Faculty of Medicine & Health, University of New South Wales, Sydney, NSW, Australia
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Xiao Z, Wu W, Ma X, Wu J, Liang X, Cao Y, Zhao Q, Ding D. Olfactory function, neurofilament light chain, and cognitive trajectory: A 12-year follow-up of the Shanghai Aging Study. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2023; 15:e12485. [PMID: 37800096 PMCID: PMC10549963 DOI: 10.1002/dad2.12485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 08/08/2023] [Accepted: 09/11/2023] [Indexed: 10/07/2023]
Abstract
This study aimed to determine whether blood neurofilament light chain (NfL) modifies the association of olfactory dysfunction (OD) with long-term cognitive decline. A total of 1125 non-demented older adults in the Shanghai Aging Study were evaluated for baseline olfaction (12-item Sniffin' Sticks Smell Test) and cognitive trajectory by a 12-year follow-up. Baseline blood NfL was quantified using Single Molecular Array assay, and dichotomized into low and high levels based on the median value of concentration. The Mini-Mental State Examination (MMSE) and Telephone Interview for Cognitive Status-40 were used to assess participants' cognitive function. Cognitive decline was ascertained when dementia was diagnosed or documented in the medical record during follow-up, or the MMSE declining rate (slope) was 1.0 SD larger than the group mean. OD participants presented a steeper trajectory of MMSE score (p interaction = 0.004) and a high risk of cognitive decline (adjusted HR [95% CI], 1.82 [1.11, 2.98]) only in those with high NfL. Participants with combined OD and high NfL showed the highest risk of cognitive decline (adjusted HR, 2.43 [1.20, 4.92]). OD, especially in combination with high blood NfL concentration, may be able to identify individuals who later incur cognitive deterioration.
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Affiliation(s)
- Zhenxu Xiao
- Institute of NeurologyHuashan HospitalFudan UniversityShanghaiChina
- National Clinical Research Center for Aging and MedicineHuashan HospitalFudan UniversityShanghaiChina
- National Center for Neurological DisordersHuashan HospitalFudan UniversityShanghaiChina
| | - Wanqing Wu
- Institute of NeurologyHuashan HospitalFudan UniversityShanghaiChina
- National Clinical Research Center for Aging and MedicineHuashan HospitalFudan UniversityShanghaiChina
- National Center for Neurological DisordersHuashan HospitalFudan UniversityShanghaiChina
| | - Xiaoxi Ma
- Institute of NeurologyHuashan HospitalFudan UniversityShanghaiChina
- National Clinical Research Center for Aging and MedicineHuashan HospitalFudan UniversityShanghaiChina
- National Center for Neurological DisordersHuashan HospitalFudan UniversityShanghaiChina
| | - Jie Wu
- Institute of NeurologyHuashan HospitalFudan UniversityShanghaiChina
- National Clinical Research Center for Aging and MedicineHuashan HospitalFudan UniversityShanghaiChina
- National Center for Neurological DisordersHuashan HospitalFudan UniversityShanghaiChina
| | - Xiaoniu Liang
- Institute of NeurologyHuashan HospitalFudan UniversityShanghaiChina
- National Clinical Research Center for Aging and MedicineHuashan HospitalFudan UniversityShanghaiChina
- National Center for Neurological DisordersHuashan HospitalFudan UniversityShanghaiChina
| | - Yang Cao
- Clinical Epidemiology and BiostatisticsSchool of Medical SciencesFaculty of Medicine and HealthÖrebro UniversityÖrebroSweden
- Unit of Integrative EpidemiologyInstitute of Environmental MedicineKarolinska InstituteStockholmSweden
| | - Qianhua Zhao
- Institute of NeurologyHuashan HospitalFudan UniversityShanghaiChina
- National Clinical Research Center for Aging and MedicineHuashan HospitalFudan UniversityShanghaiChina
- National Center for Neurological DisordersHuashan HospitalFudan UniversityShanghaiChina
- MOE Frontiers Center for Brain ScienceFudan UniversityShanghaiChina
| | - Ding Ding
- Institute of NeurologyHuashan HospitalFudan UniversityShanghaiChina
- National Clinical Research Center for Aging and MedicineHuashan HospitalFudan UniversityShanghaiChina
- National Center for Neurological DisordersHuashan HospitalFudan UniversityShanghaiChina
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Woo CC, Miranda B, Sathishkumar M, Dehkordi-Vakil F, Yassa MA, Leon M. Overnight olfactory enrichment using an odorant diffuser improves memory and modifies the uncinate fasciculus in older adults. Front Neurosci 2023; 17:1200448. [PMID: 37554295 PMCID: PMC10405466 DOI: 10.3389/fnins.2023.1200448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 07/07/2023] [Indexed: 08/10/2023] Open
Abstract
OBJECTIVE Cognitive loss in older adults is a growing issue in our society, and there is a need to develop inexpensive, simple, effective in-home treatments. This study was conducted to explore the use of olfactory enrichment at night to improve cognitive ability in healthy older adults. METHODS Male and female older adults (N = 43), age 60-85, were enrolled in the study and randomly assigned to an Olfactory Enriched or Control group. Individuals in the enriched group were exposed to 7 different odorants a week, one per night, for 2 h, using an odorant diffuser. Individuals in the control group had the same experience with de minimis amounts of odorant. Neuropsychological assessments and fMRI scans were administered at the beginning of the study and after 6 months. RESULTS A statistically significant 226% improvement was observed in the enriched group compared to the control group on the Rey Auditory Verbal Learning Test and improved functioning was observed in the left uncinate fasciculus, as assessed by mean diffusivity. CONCLUSION Minimal olfactory enrichment administered at night produces improvements in both cognitive and neural functioning. Thus, olfactory enrichment may provide an effective and low-effort pathway to improved brain health.
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Affiliation(s)
- Cynthia C. Woo
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
| | - Blake Miranda
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, United States
| | - Mithra Sathishkumar
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, United States
| | | | - Michael A. Yassa
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, United States
| | - Michael Leon
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, United States
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA, United States
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Tian Q, An Y, Kitner-Triolo MH, Davatzikos C, Studenski SA, Ferrucci L, Resnick SM. Associations of Olfaction With Longitudinal Trajectories of Brain Volumes and Neuropsychological Function in Older Adults. Neurology 2023; 100:e964-e974. [PMID: 36460474 PMCID: PMC9990434 DOI: 10.1212/wnl.0000000000201646] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 10/18/2022] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Olfactory function declines with aging, and olfactory deficits are one of the earliest features of neurodegenerative diseases, such as Parkinson disease and Alzheimer disease. Previous studies have shown that olfaction is associated with brain volumes and cognitive function, but data are exclusively cross-sectional. We aimed to examine longitudinal associations of olfaction with changes in brain volumes and neuropsychological function. METHODS In the Baltimore Longitudinal Study of Aging, we chose the first assessment of olfaction to examine the associations with retrospective and prospective changes in neuropsychological performance and brain volumes in participants aged 50 years or older using linear mixed-effects models, adjusted for demographic variables and cardiovascular disease. Olfaction was measured as odor identification scores through the 16-item Sniffin' Sticks. RESULTS We analyzed data from 567 (58% women, 42% men, 27% Black, 66% White, and 7% others) participants who had data on odor identification scores and brain volumetric MRI (n = 420 with retrospective repeats over a mean of 3.7 years, n = 280 with prospective repeats over a mean of 1.2 years). We also analyzed data from 754 participants (56% women, 44% men, 29% Black, 65% White, and 6% others) with neuropsychological assessments (n = 630 with retrospective repeats over a mean of 6.6 years, n = 280 with prospective repeats over a mean of 1.5 years). After adjustment, higher odor identification scores were associated with prior and subsequent slower brain atrophy in the entorhinal cortex (β ± SE = 0.0093 ± 0.0031, p = 0.0028 and β ± SE = 0.0176 ± 0.0073, p = 0.0169, respectively), hippocampus (β ± SE = 0.0070 ± 0.0030, p = 0.0192 and β ± SE = 0.0173 ± 0.0066, p = 0.0089, respectively), and additional frontal and temporal areas (all p < 0.05). Higher odor identification scores were also associated with prior slower decline in memory, attention, processing speed, and manual dexterity and subsequent slower decline in attention (all p < 0.05). Some associations were attenuated after exclusion of data points at and after symptom onset of cognitive impairment or dementia. DISCUSSION In older adults, olfaction is related to brain atrophy of specific brain regions and neuropsychological changes in specific domains over time. The observed associations are driven, in part, by those who developed cognitive impairment or dementia. Future longitudinal studies with longer follow-ups are needed to understand whether olfactory decline precedes cognitive decline and whether it is mediated through regionally specific brain atrophy.
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Affiliation(s)
- Qu Tian
- From the Translational Gerontology Branch (Q.T., S.A.S., L.F.), National Institute on Aging, Baltimore, MD; Laboratory of Behavioral Neuroscience (Y.A., M.H.K.T., S.M.R.), National Institute on Aging, Baltimore, MD; and Department of Radiology (C.D.), University of Pennsylvania School of Medicine, Philadelphia.
| | - Yang An
- From the Translational Gerontology Branch (Q.T., S.A.S., L.F.), National Institute on Aging, Baltimore, MD; Laboratory of Behavioral Neuroscience (Y.A., M.H.K.T., S.M.R.), National Institute on Aging, Baltimore, MD; and Department of Radiology (C.D.), University of Pennsylvania School of Medicine, Philadelphia.
| | - Melissa H Kitner-Triolo
- From the Translational Gerontology Branch (Q.T., S.A.S., L.F.), National Institute on Aging, Baltimore, MD; Laboratory of Behavioral Neuroscience (Y.A., M.H.K.T., S.M.R.), National Institute on Aging, Baltimore, MD; and Department of Radiology (C.D.), University of Pennsylvania School of Medicine, Philadelphia
| | - Christos Davatzikos
- From the Translational Gerontology Branch (Q.T., S.A.S., L.F.), National Institute on Aging, Baltimore, MD; Laboratory of Behavioral Neuroscience (Y.A., M.H.K.T., S.M.R.), National Institute on Aging, Baltimore, MD; and Department of Radiology (C.D.), University of Pennsylvania School of Medicine, Philadelphia
| | - Stephanie A Studenski
- From the Translational Gerontology Branch (Q.T., S.A.S., L.F.), National Institute on Aging, Baltimore, MD; Laboratory of Behavioral Neuroscience (Y.A., M.H.K.T., S.M.R.), National Institute on Aging, Baltimore, MD; and Department of Radiology (C.D.), University of Pennsylvania School of Medicine, Philadelphia
| | - Luigi Ferrucci
- From the Translational Gerontology Branch (Q.T., S.A.S., L.F.), National Institute on Aging, Baltimore, MD; Laboratory of Behavioral Neuroscience (Y.A., M.H.K.T., S.M.R.), National Institute on Aging, Baltimore, MD; and Department of Radiology (C.D.), University of Pennsylvania School of Medicine, Philadelphia
| | - Susan M Resnick
- From the Translational Gerontology Branch (Q.T., S.A.S., L.F.), National Institute on Aging, Baltimore, MD; Laboratory of Behavioral Neuroscience (Y.A., M.H.K.T., S.M.R.), National Institute on Aging, Baltimore, MD; and Department of Radiology (C.D.), University of Pennsylvania School of Medicine, Philadelphia
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Leon M, Woo CC. Olfactory loss is a predisposing factor for depression, while olfactory enrichment is an effective treatment for depression. Front Neurosci 2022; 16:1013363. [PMID: 36248633 PMCID: PMC9558899 DOI: 10.3389/fnins.2022.1013363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 09/08/2022] [Indexed: 11/13/2022] Open
Abstract
The loss of olfactory stimulation correlates well with at least 68 widely differing neurological disorders, including depression, and we raise the possibility that this relationship may be causal. That is, it seems possible that olfactory loss makes the brain vulnerable to expressing the symptoms of these neurological disorders, while daily olfactory enrichment may decrease the risk of expressing these symptoms. This situation resembles the cognitive reserve that is thought to protect people with Alzheimer’s neuropathology from expressing the functional deficit in memory through the cumulative effect of intellectual stimulation. These relationships also resemble the functional response of animal models of human neurological disorders to environmental enrichment, wherein the animals continue to have the induced neuropathology, but do not express the symptoms as they do in a standard environment with restricted sensorimotor stimulation.
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Affiliation(s)
- Michael Leon
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
- Center for the Neurobiology of Learning and Memory, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA, United States
- *Correspondence: Michael Leon,
| | - Cynthia C. Woo
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
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Challakere Ramaswamy VM, Schofield PW. Olfaction and Executive Cognitive Performance: A Systematic Review. Front Psychol 2022; 13:871391. [PMID: 35615205 PMCID: PMC9125097 DOI: 10.3389/fpsyg.2022.871391] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 04/14/2022] [Indexed: 11/30/2022] Open
Abstract
Objective tests of olfaction are widely available to aid in the assessment of olfaction. Their clearest role is in the characterization of olfactory changes, either reported by or suspected in a patient. There is a rapidly growing literature concerned with the association of olfactory changes with certain neuropsychiatric conditions and the use of olfactory testing to supplement conventional assessments in clinical and research practice is evolving. Neural pathways important for olfactory processing overlap extensively with pathways important for cognitive functioning, and especially those important for executive functioning, many of which are concentrated in the frontal lobes. Previous work has identified associations between performance on certain olfactory tests (most frequently olfactory identification) and executive functioning and behavioral measures (e.g. of impulsivity). More recently, similar associations have also been identified in non-clinical samples, raising new questions as to the utility of olfactory test scores as proxy measures for non-olfactory phenomena. In this systemic review, we sought to identify studies, both clinical and non-clinical, that investigated the associations of olfaction with performance on tasks sensitive to frontal lobe functioning. Our search criteria led to the identification of 70 studies published in English. We examined in detail and tabulated the data from these studies, highlighted each study's key findings, and critically evaluated these studies. We use the results of this review to reflect on some of the current and future challenges concerning the use of olfactory testing in clinical neuropsychiatric practice and research and speculate on the potential benefits of administering phonemic fluency in combination with olfactory testing to enhance its predictive value.
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Affiliation(s)
- Vasudeva Murthy Challakere Ramaswamy
- School of Medicine and Public Health, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia
- *Correspondence: Vasudeva Murthy Challakere Ramaswamy
| | - Peter William Schofield
- School of Medicine and Public Health, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia
- Neuropsychiatry Service, Hunter New England Mental Health, New Lambton, NSW, Australia
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Patel ZM, Holbrook EH, Turner JH, Adappa ND, Albers MW, Altundag A, Appenzeller S, Costanzo RM, Croy I, Davis GE, Dehgani-Mobaraki P, Doty RL, Duffy VB, Goldstein BJ, Gudis DA, Haehner A, Higgins TS, Hopkins C, Huart C, Hummel T, Jitaroon K, Kern RC, Khanwalkar AR, Kobayashi M, Kondo K, Lane AP, Lechner M, Leopold DA, Levy JM, Marmura MJ, Mclelland L, Miwa T, Moberg PJ, Mueller CA, Nigwekar SU, O'Brien EK, Paunescu TG, Pellegrino R, Philpott C, Pinto JM, Reiter ER, Roalf DR, Rowan NR, Schlosser RJ, Schwob J, Seiden AM, Smith TL, Soler ZM, Sowerby L, Tan BK, Thamboo A, Wrobel B, Yan CH. International consensus statement on allergy and rhinology: Olfaction. Int Forum Allergy Rhinol 2022; 12:327-680. [PMID: 35373533 DOI: 10.1002/alr.22929] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 01/01/2021] [Accepted: 11/19/2021] [Indexed: 12/11/2022]
Abstract
BACKGROUND The literature regarding clinical olfaction, olfactory loss, and olfactory dysfunction has expanded rapidly over the past two decades, with an exponential rise in the past year. There is substantial variability in the quality of this literature and a need to consolidate and critically review the evidence. It is with that aim that we have gathered experts from around the world to produce this International Consensus on Allergy and Rhinology: Olfaction (ICAR:O). METHODS Using previously described methodology, specific topics were developed relating to olfaction. Each topic was assigned a literature review, evidence-based review, or evidence-based review with recommendations format as dictated by available evidence and scope within the ICAR:O document. Following iterative reviews of each topic, the ICAR:O document was integrated and reviewed by all authors for final consensus. RESULTS The ICAR:O document reviews nearly 100 separate topics within the realm of olfaction, including diagnosis, epidemiology, disease burden, diagnosis, testing, etiology, treatment, and associated pathologies. CONCLUSION This critical review of the existing clinical olfaction literature provides much needed insight and clarity into the evaluation, diagnosis, and treatment of patients with olfactory dysfunction, while also clearly delineating gaps in our knowledge and evidence base that we should investigate further.
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Affiliation(s)
- Zara M Patel
- Otolaryngology, Stanford University School of Medicine, Stanford, California, USA
| | - Eric H Holbrook
- Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - Justin H Turner
- Otolaryngology, Vanderbilt School of Medicine, Nashville, Tennessee, USA
| | - Nithin D Adappa
- Otolaryngology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mark W Albers
- Neurology, Harvard Medical School, Boston, Massachusetts, USA
| | - Aytug Altundag
- Otolaryngology, Biruni University School of Medicine, İstanbul, Turkey
| | - Simone Appenzeller
- Rheumatology, School of Medical Sciences, University of Campinas, São Paulo, Brazil
| | - Richard M Costanzo
- Physiology and Biophysics and Otolaryngology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Ilona Croy
- Psychology and Psychosomatic Medicine, TU Dresden, Dresden, Germany
| | - Greg E Davis
- Otolaryngology, Proliance Surgeons, Seattle and Puyallup, Washington, USA
| | - Puya Dehgani-Mobaraki
- Associazione Naso Sano, Umbria Regional Registry of Volunteer Activities, Corciano, Italy
| | - Richard L Doty
- Smell and Taste Center, Otolaryngology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Valerie B Duffy
- Allied Health Sciences, University of Connecticut, Storrs, Connecticut, USA
| | | | - David A Gudis
- Otolaryngology, Columbia University Irving Medical Center, New York, USA
| | - Antje Haehner
- Smell and Taste, Otolaryngology, TU Dresden, Dresden, Germany
| | - Thomas S Higgins
- Otolaryngology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Claire Hopkins
- Otolaryngology, Guy's and St. Thomas' Hospitals, London Bridge Hospital, London, UK
| | - Caroline Huart
- Otorhinolaryngology, Cliniques universitaires Saint-Luc, Institute of Neuroscience, Université catholgique de Louvain, Brussels, Belgium
| | - Thomas Hummel
- Smell and Taste, Otolaryngology, TU Dresden, Dresden, Germany
| | | | - Robert C Kern
- Otolaryngology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Ashoke R Khanwalkar
- Otolaryngology, Stanford University School of Medicine, Stanford, California, USA
| | - Masayoshi Kobayashi
- Otorhinolaryngology-Head and Neck Surgery, Mie University Graduate School of Medicine, Mie, Japan
| | - Kenji Kondo
- Otolaryngology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Andrew P Lane
- Otolaryngology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Matt Lechner
- Otolaryngology, Barts Health and University College London, London, UK
| | - Donald A Leopold
- Otolaryngology, University of Vermont Medical Center, Burlington, Vermont, USA
| | - Joshua M Levy
- Otolaryngology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Michael J Marmura
- Neurology Thomas Jefferson University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Lisha Mclelland
- Otolaryngology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Takaki Miwa
- Otolaryngology, Kanazawa Medical University, Ishikawa, Japan
| | - Paul J Moberg
- Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | | | - Sagar U Nigwekar
- Division of Nephrology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Erin K O'Brien
- Otolaryngology, Mayo Clinic Rochester, Rochester, Minnesota, USA
| | - Teodor G Paunescu
- Division of Nephrology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | | | - Carl Philpott
- Otolaryngology, University of East Anglia, Norwich, UK
| | - Jayant M Pinto
- Otolaryngology, University of Chicago, Chicago, Illinois, USA
| | - Evan R Reiter
- Otolaryngology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - David R Roalf
- Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Nicholas R Rowan
- Otolaryngology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Rodney J Schlosser
- Otolaryngology, Medical University of South Carolina, Mt Pleasant, South Carolina, USA
| | - James Schwob
- Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Allen M Seiden
- Otolaryngology, University of Cincinnati School of Medicine, Cincinnati, Ohio, USA
| | - Timothy L Smith
- Otolaryngology, Oregon Health and Sciences University, Portland, Oregon, USA
| | - Zachary M Soler
- Otolaryngology, Medical University of South Carolina, Mt Pleasant, South Carolina, USA
| | - Leigh Sowerby
- Otolaryngology, University of Western Ontario, London, Ontario, Canada
| | - Bruce K Tan
- Otolaryngology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Andrew Thamboo
- Otolaryngology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Bozena Wrobel
- Otolaryngology, Keck School of Medicine, USC, Los Angeles, California, USA
| | - Carol H Yan
- Otolaryngology, School of Medicine, UCSD, La Jolla, California, USA
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Li J, Bur AM, Villwock MR, Shankar S, Palmer G, Sykes KJ, Villwock JA. Olfactory Phenotypes Differentiate Cognitively Unimpaired Seniors from Alzheimer's Disease and Mild Cognitive Impairment: A Combined Machine Learning and Traditional Statistical Approach. J Alzheimers Dis 2021; 81:641-650. [PMID: 33843686 DOI: 10.3233/jad-210175] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Olfactory dysfunction (OD) is an early symptom of Alzheimer's disease (AD). However, olfactory testing is not commonly performed to test OD in the setting of AD. OBJECTIVE This work investigates objective OD as a non-invasive biomarker for accurately classifying subjects as cognitively unimpaired (CU), mild cognitive impairment (MCI), and AD. METHODS Patients with MCI (n = 24) and AD (n = 24), and CU (n = 33) controls completed two objective tests of olfaction (Affordable, Rapid, Olfactory Measurement Array -AROMA; Sniffin' Sticks Screening 12 Test -SST12). Demographic and subjective sinonasal and olfaction symptom information was also obtained. Analyses utilized traditional statistics and machine learning to determine olfactory variables, and combinations of variables, of importance for differentiating normal and disease states. RESULTS Inability to correctly identify a scent after detection was a hallmark of MCI/AD. AROMA was superior to SST12 for differentiating MCI from AD. Performance on the clove scent was significantly different between all three groups. AROMA regression modeling yielded six scents with AUC of the ROC of 0.890 (p < 0.001). Random forest model machine learning algorithms considering AROMA olfactory data successfully predicted MCI versus AD disease state. Considering only AROMA data, machine learning algorithms were 87.5%accurate (95%CI 0.4735, 0.9968). Sensitivity and specificity were 100%and 75%, respectively with ROC of 0.875. When considering AROMA and subject demographic and subjective data, the AUC of the ROC increased to 0.9375. CONCLUSION OD differentiates CUs from those with MCI and AD and can accurately predict MCI versus AD. Leveraging OD data may meaningfully guide management and research decisions.
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Affiliation(s)
- Jennifer Li
- University of Kansas Medical Center, Department of Otolaryngology - Head and Neck Surgery, Kansas City, KS, USA
| | - Andres M Bur
- University of Kansas Medical Center, Department of Otolaryngology - Head and Neck Surgery, Kansas City, KS, USA
| | - Mark R Villwock
- University of Kansas Medical Center, Department of Otolaryngology - Head and Neck Surgery, Kansas City, KS, USA
| | - Suraj Shankar
- University of Kansas Medical Center, Department of Otolaryngology - Head and Neck Surgery, Kansas City, KS, USA
| | - Gracie Palmer
- University of Kansas Medical Center, Department of Otolaryngology - Head and Neck Surgery, Kansas City, KS, USA
| | - Kevin J Sykes
- University of Kansas Medical Center, Department of Otolaryngology - Head and Neck Surgery, Kansas City, KS, USA
| | - Jennifer A Villwock
- University of Kansas Medical Center, Department of Otolaryngology - Head and Neck Surgery, Kansas City, KS, USA
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Jang SS, Choi JS, Kim JH, Kim N, Ference EH. Discordance Between Subjective and Objective Measures of Smell and Taste in US Adults. Otolaryngol Head Neck Surg 2021; 166:572-579. [PMID: 34154442 DOI: 10.1177/01945998211018386] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Examine the rates and factors associated with under- and overreporting of subjective changes in smell or taste as compared with objective measures. STUDY DESIGN Cross-sectional analysis. SETTING National Health and Nutrition Examination Survey (2013-2014). METHODS We examined participants ≥40 years old who completed subjective questionnaires (smell, n = 3510; taste, n = 3089), validated objective 8-odor pocket smell tests, and NaCl/quinine taste tests. Over- and underreporting was determined by the difference in subjective and objective results. Univariate and multivariate logistic regression analyses incorporated sampling weights. RESULTS A majority of participants correctly classified impairment: smell (73.7%; 95% CI, 71.2%-76.1%) and taste (78.3%; 95% CI, 75.6%-80.7%). Age ≥65 years (odds ratio, 2.23; P = .001) was associated with underreporting impairment, and persistent cold symptoms (odds ratio, 2.15; P = .001) were associated with overreporting smell impairment. Smoke, onion, and natural gas scents were incorrectly identified more frequently by individuals aged ≥65 years after Bonferroni correction. No factors were associated with under- and overreporting taste impairment. CONCLUSION Although the concordance rate between subjective and objective assessment of smell and taste impairment remains high, we found that older age was associated with incorrect report of impairment. This suggests that the subjective perception of smell varies across demographical and clinical factors, and it is important to not overlook such factors in clinical practice. Potentially using a simplified odor assessment regularly in the clinical setting may aid in early detection and intervention.
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Affiliation(s)
- Sophie S Jang
- Royal College of Surgeons in Ireland, Dublin, Republic of Ireland
| | - Janet S Choi
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
| | - James H Kim
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
| | - Natalie Kim
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
| | - Elisabeth H Ference
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
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Olofsson JK. Olfaction and Aging: A Review of the Current State of Research and Future Directions. Iperception 2021; 12:20416695211020331. [PMID: 34249327 PMCID: PMC8239976 DOI: 10.1177/20416695211020331] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 04/21/2021] [Indexed: 11/16/2022] Open
Abstract
Olfaction, the sense of smell, is characterized by a notable age-dependency such that aging individuals are more likely to have poor olfactory abilities. These impairments are considered to be mostly irreversible and as having potentially profound effects on quality of life and food behavior, as well as constituting warning signs of mortality, cognitive dysfunction, and dementia. Here, we review the current state of research on aging and olfaction, focusing on five topics which we regard to be of particular relevance for the field: nutrition and health, cognition and dementia, mortality, environment and genetics, and training-based enhancement. Under each of these headlines, we provide a state-of-the-art overview and discuss gaps in our knowledge which might be filled by further research. Understanding how olfactory abilities are diminished in aging, and how they may be alleviated or recovered, involves a set of challenging tasks for researchers in the years to come.
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Affiliation(s)
- Jonas K. Olofsson
- Gösta Ekman Laboratory, Stockholm University, Stockholm, Sweden; Department of Psychology, Stockholm University, Stockholm, Sweden
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12
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Choi JS, Jang SS, Kim J, Hur K, Ference E, Wrobel B. Association Between Olfactory Dysfunction and Mortality in US Adults. JAMA Otolaryngol Head Neck Surg 2021; 147:49-55. [PMID: 33090196 DOI: 10.1001/jamaoto.2020.3502] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Importance A study of olfactory dysfunction and mortality in a large national cohort will aid in better understanding their association when accounting for multiple relevant factors and possible underlying mechanisms. Objective To investigate the association of olfactory dysfunction with all-cause 5-year mortality in US adults. Design, Setting, and Participants This cohort study included participants 40 years or older from the 2013-2014 National Health and Nutritional Examination Survey who had data on olfaction and mortality (n = 3503). Olfaction was assessed by self-report and objective test (8-odor Pocket Smell Test). Mortality was determined by linking with the National Death Index through February 24, 2019. Data were analyzed from July 1 to September 30, 2019. Main Outcomes and Measures Olfaction and 5-year mortality. Cox proportional regression models were used to examine the associations between olfaction and mortality while adjusting for demographics and medical comorbidities. Multivariate models were further adjusted for depression and cognitive assessments. Results Among the 3503 participants (1831 women [52.3%]; mean [SD] age, 59.0 [12.0] years), the prevalence of olfactory dysfunction was 13.5% (95% CI, 11.0%-16.0%) based on results of an objective smell test and 21.6% (95% CI, 18.9%-24.2%) based on self-report. Risk of mortality increased by 18% (95% CI, 7%-29%) per 1-point decrease in smell test score in a multivariate model. The association was significant among adults 65 years or older in association with binary (hazard ratio [HR], 1.95; 95% CI, 1.19-3.21) and linear (HR, 1.19; 95% CI, 1.08-1.31) measures of objective olfactory dysfunction, but not among adults aged 40 to 64 years. There was no association between self-reported olfactory dysfunction and mortality. The association between objective olfactory dysfunction and mortality remained after further adjusting for cognitive assessment battery and depression among older adults (HR, 1.18; 95% CI, 1.01-1.37). Conclusions and Relevance These findings suggest that objective olfactory dysfunction is associated with increased mortality among older adults. In addition to its effect on quality of life, the association of olfactory dysfunction with mortality has implications for physical and cognitive health.
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Affiliation(s)
- Janet S Choi
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles
| | | | - Jeehong Kim
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles
| | - Kevin Hur
- Department of Otolaryngology-Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Elisabeth Ference
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles
| | - Bozena Wrobel
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles
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13
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Abstract
Age-related olfactory dysfunction, or presbyosmia, is a common sensory impairment in aging adults. People in this demographic group with comorbid conditions or exposure to viral, traumatic, or environmental insults remain at the greatest risk for impairment. Several methods for assessing olfaction exist, but they are only available in special settings and require consideration of age, sex, ancestry, and cognition. Perhaps most importantly, olfactory dysfunction has been suggested as an early sign of Alzheimer's and Parkinson's disease and therefore may serve as a tool in the diagnosis and prognosis of these neurodegenerative conditions. Outside of this context, olfactory loss also impacts nutrition, safety, and social relationships, and even predicts mortality itself. This review covers the detection and manifestations of olfactory decline in aging individuals and the myriad ways in which olfactory impairment is connected to their health and well-being.
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Affiliation(s)
- Emily J Papazian
- Pritzker School of Medicine, The University of Chicago, Chicago, IL, USA
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Jayant M Pinto
- Section of Otolaryngology-Head and Neck Surgery, Department of Surgery, The University of Chicago Medicine, Chicago, IL, USA
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14
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Chen Z, Xie H, Yao L, Wei Y. Olfactory impairment and the risk of cognitive decline and dementia in older adults: a meta-analysis. Braz J Otorhinolaryngol 2020; 87:94-102. [PMID: 32978117 PMCID: PMC9422530 DOI: 10.1016/j.bjorl.2020.07.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 06/18/2020] [Accepted: 07/11/2020] [Indexed: 11/30/2022] Open
Abstract
Introduction The prediction of the impact of olfactory impairment on cognitive decline in older adults has been different among different age groups. Objective This meta-analysis sought to estimate the predictive power of olfactory impairment on cognitive decline during follow-up in older adults of different ages. Material and methods A medical literature search was carried out using these databases for eligible studies: MEDLINE, COCHRANE and EMBASE. Studies recording olfaction and cognition detection at the beginning and end of the follow-up were included in the preliminary screening. The medical records of older adults without cognitive impairment at the beginning of the follow-up were taken into account in this analysis. Raw data was extracted in order to estimate the relative risk and the corresponding 95% confidence interval (95% CI). Subgroup analysis of age was performed to eliminate the effect of age on the results. Statistical heterogeneity was measured using the I2 index and Cochran's Q test. Results Eight studies were enrolled in this analysis (3237 events and 13165 participants), and the pooled relative risk for the 70–80 years old subgroup was 2.00 (95% CI = 1.79–2.23). Conclusion Relatively, there is a higher risk of cognitive impairment at the end of follow-up in younger adults with olfactory impairment at the beginning of follow-up. The length of follow-up has a little effect on the relative risk.
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Affiliation(s)
- Zirong Chen
- Beijing Institute of Heart Lung and Blood Vessel Diseases, Beijing, China; Capital Medical University, Beijing AnZhen Hospital, Otolaryngology Head and Neck Surgery Department, Beijing, China
| | - Hongbo Xie
- Beijing Institute of Heart Lung and Blood Vessel Diseases, Beijing, China; Capital Medical University, Beijing AnZhen Hospital, Otolaryngology Head and Neck Surgery Department, Beijing, China
| | - Linyin Yao
- Capital Medical University, Beijing AnZhen Hospital, Otolaryngology Head and Neck Surgery Department, Beijing, China
| | - Yongxiang Wei
- Beijing Institute of Heart Lung and Blood Vessel Diseases, Beijing, China; Capital Medical University, Beijing AnZhen Hospital, Otolaryngology Head and Neck Surgery Department, Beijing, China.
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Gallo S, Byham-Gray L, Duffy VB, Hoffman HJ, Hayes JE, Rawal S. Associations of olfactory dysfunction with anthropometric and cardiometabolic measures: Findings from the 2013-2014 national health and nutrition examination survey (NHANES). Physiol Behav 2019; 215:112702. [PMID: 31629766 DOI: 10.1016/j.physbeh.2019.112702] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 10/04/2019] [Accepted: 10/06/2019] [Indexed: 12/14/2022]
Abstract
We examined associations of olfactory dysfunction with anthropometric and cardiometabolic measures in a nationally representative sample of US adults. In the 2013-2014 National Health and Nutrition Examination Survey (NHANES), 3,815 participants, 40 years and older, completed a standardized taste and smell protocol, which consisted of an 8-item odor identification test and a chemosensory questionnaire. Measured dysfunction was incorrect identification of ≥3 of 8 odors; self-reported dysfunction was affirmative response to either a recent smell problem, worse ability since age 25, or phantosmia. Survey-weighted linear regression models tested associations of olfactory dysfunction with body mass index (BMI), waist circumference (WC), blood pressure, serum total cholesterol (TC) with fractions, triglycerides, and glucose levels. Models were adjusted for age, race, education, physical activity, self-reported general health condition, smoking history, and income-to-poverty ratio, stratifying by sex and age group (middle-age 40-64 years; older ≥65 years). Relative to normal, measured olfactory dysfunction was associated with lower BMI [β=-1.6 (95% CI: -3.2, -0.01)] in older men. In middle-age women, dysfunction was associated with higher BMI and WC, whether assessed by examination [β's for BMI=3.1 (0.6, 5.5), WC=5.0 (0.3, 9.8)] or self-report [β's for BMI=2.5 (0.6, 4.3), WC=6.1 (2.2, 9.9)]. Measured dysfunction was associated with significantly higher TC [β=12.8 (7.5, 18.1)] and LDL [β=18.1 (9.1, 27.2)] among older men, but significantly lower TC [β=-15.0 (-25.0, -5.7)] and marginally lower LDL [β=-12.0 (-25.0, 1.2)] among older women. Between measured dysfunction and fasting glucose, the association was inverse [β=-7.9 (-13.0, -2.6)] among middle-age men, but positive [β=15.6 (1.5, 29.7)] among older women. No significant associations were observed with blood pressure levels. In conclusion, among US adults ≥40 years, olfactory dysfunction is associated with anthropometric and glucose and lipid levels, with associations varying by sex and age group.
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Affiliation(s)
- Samantha Gallo
- Department of Clinical and Preventive Nutrition Sciences, Rutgers School of Health Professions, 65 Bergen St., Newark, NJ 07107-1709 USA.
| | - Laura Byham-Gray
- Department of Clinical and Preventive Nutrition Sciences, Rutgers School of Health Professions, 65 Bergen St., Newark, NJ 07107-1709 USA.
| | - Valerie B Duffy
- Department of Allied Health Sciences, University of Connecticut, 358 Mansfield Rd, Storrs, CT 06269, USA.
| | - Howard J Hoffman
- Epidemiology and Statistics Program, Division of Scientific Programs, National Institute on Deafness and Other Communication Disorders, National Institutes of Health (NIH), 10 Center Dr., Bethesda, MD 20892, USA.
| | - John E Hayes
- Sensory Evaluation Center, The Pennsylvania State University, 220 Erickson Food Science Building, University Park, PA 16802, USA; Department of Food Science, College of Agricultural Sciences, The Pennsylvania State University, 220 Erickson Food Science Building, University Park, PA 16802, USA.
| | - Shristi Rawal
- Department of Clinical and Preventive Nutrition Sciences, Rutgers School of Health Professions, 65 Bergen St., Newark, NJ 07107-1709 USA.
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16
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First recognized n-butanol concentration may be simple and useful index for assessing olfactory dysfunction in geriatric patients. Aging Clin Exp Res 2019; 31:1169-1173. [PMID: 30539539 DOI: 10.1007/s40520-018-1092-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 12/06/2018] [Indexed: 10/27/2022]
Abstract
The KVSSII is widely used to evaluate olfactory function in the Korean population. We evaluated the usefulness of the first recognized n-butanol concentration, which is obtained at the beginning part of KVSS II, in predicting olfactory dysfunction. Three hundred seventy two subjects were enrolled in our study. The results of KVSS II and the demographic characteristics were statistically analyzed. The first recognized n-butanol concentration was positively correlated with the result of KVSS II. The mean value of first recognized n-butanol concentration was 5.59 ± 1.42 in normosmia, 4.10 ± 1.40 in hyposmia, and 0.84 ± 1.68 in the anosmia group. By ROC curve, cut-off value of 2.5 showed sensitivity of 85.9% and specificity of 90.6% for anosmia, and cut-off value of 4.5 showed sensitivity of 77.6% and specificity of 69.8% for hyposmia. Consequently, we suggest that it may be useful in assessing olfactory function, in geriatric patients who are not able to tolerate conventional KVSS II.
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17
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Bleier BS. A "golden age" in skull base and rhinology research. Int Forum Allergy Rhinol 2019; 8:561-562. [PMID: 29694736 DOI: 10.1002/alr.22130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Churnin I, Qazi J, Fermin CR, Wilson JH, Payne SC, Mattos JL. Association Between Olfactory and Gustatory Dysfunction and Cognition in Older Adults. Am J Rhinol Allergy 2019; 33:170-177. [DOI: 10.1177/1945892418824451] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background The association between olfactory dysfunction (OD) and cognitive decline is becoming apparent in the emerging literature. However, the literature demonstrating a similar effect between gustatory dysfunction (GD) and cognition is not well established. Objective To determine whether OD and GD are independently associated with cognitive impairment. Methods The 2013–2014 National Health and Nutrition Examination Survey was queried for 1376 older adults, corresponding to a weighted population sample of 50 816 529, to assess olfactory and gustatory status and cognition using univariate and multivariate regression analyses. OD and GD were determined using objective measurements with validated protocols. Participants were stratified as normal or abnormal cognition status using accepted cutoff values as indicated for the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) neuropsychological test, Animal Fluency Test (AFT), and Digit Symbol Substitution Test (DSST). Results OD was associated with both mild cognitive impairment (odds ratio [OR] 1.809, P = .004) and dementia (OR 3.173, P < .001) with CERAD testing, abnormal AFT (OR 2.424, P < .001), and abnormal DSST (OR 4.028, P < .001). GD based on 1M NaCl whole mouth taste testing was associated with dementia on CERAD testing (OR 2.217, P = .004). When smell and taste parameters were included together in the regression model, both OD and GD remained significant independent predictors of dementia status based on CERAD testing (OR 3.133, P < .001, OR 1.904, P = .015). Conclusions OD and severe GD represent independent predictors of cognitive impairment in a nationally representative sample of older adults.
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Affiliation(s)
- Ian Churnin
- Department of Otolaryngology – Head & Neck Surgery, University of Virginia, Charlottesville, Virginia
| | - Jamiluddin Qazi
- School of Medicine, University of Virginia, Charlottesville, Virginia
| | - Cyrelle R. Fermin
- School of Medicine, University of Virginia, Charlottesville, Virginia
| | - James H. Wilson
- School of Medicine, University of Virginia, Charlottesville, Virginia
| | - Spencer C. Payne
- Department of Otolaryngology – Head & Neck Surgery, University of Virginia, Charlottesville, Virginia
| | - Jose L. Mattos
- Department of Otolaryngology – Head & Neck Surgery, University of Virginia, Charlottesville, Virginia
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