Olfactory Dysfunction Associated with Cognitive Decline in an Elderly Population

ABSTRACT

Background

In many neurological disorders, including Alzheimer disease, early olfactory dysfunction is observed.

Objective

In order to determine if deficits in olfactory memory are present in the elderly and if olfactory dysfunction correlates with cognitive impairment in the aging population, olfactory testing has been done on seniors from the NuAge cohort accepting to participate in the Olfactory Response Cognition and Aging (ORCA) secondary sub-study. The t-Mini Mental Statement Examination and the Telephone Interview for Cognitive Status tests were done to assess cognition levels.

Results

Overall, 94% of the ORCA cohort displayed olfactory dysfunction. Deficits in olfactory memory were also present. A correlation was observed between olfactory function and cognitive test scores. Moreover, in women who smoked, there was an association between olfactory memory and cognitive scores.

Conclusion

Our results suggest that olfactory dysfunction may predict impending cognitive decline and highlights the need for olfactory training in seniors to improve olfaction and overall well-being.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The NuAge study was supported by a research grant from the Canadian Institutes of Health Research (CIHR; MOP-62842). The NuAge Database and Biobank are supported by the Fonds de recherche du Québec (FRQ; 2020-VICO-279753); the Quebec Network for Research on Aging (a thematic network funded by the Fonds de Recherche du Québec - Santé (FRQS)) and by the Merck-Frosst Chair funded by La Fondation de l’Université de Sherbrooke. We thank the Consortium for the Early Identification of Alzheimer’s Disease - Quebec (CIMA-Q) for their financial support for the completion of the 2014-2017 follow-up calls of NuAge participants. The CIMA-Q is supported by the Fonds d’Innovation Pfizer - Fonds de Recherche Québec – Santé sur la maladie d’Alzheimer et les maladies apparentées (Pfizer-FRQS; #27239); RQRV, Courtois Foundation NeuroMod project and the Fondation Famille Lemaire. The work in this study was supported by a grant from the Fondation Université de Sherbrooke Merck Sharpe & Dohme; a pilot grant from the Research Centre on Aging CSSS-IUGS, and, in part, by the Canada Research chairs (CRC) program. RKG previously held the CRC in Neurodegenerative diseases and now holds a FRQS Junior 2 salary award. MO is supported by a salary grant King Abdullah International Medical Research Center. The authors wish to thank Helene Payette, NuAge and CIMA-Q teams, for their technical and scientific support of the work.