Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Feb;19(2):589-601.
doi: 10.1002/alz.12777. Epub 2022 Sep 15.

Anosmia, mild cognitive impairment, and biomarkers of brain aging in older adults

Yi Dong  1   2 , Yuanjing Li  3 , Keke Liu  1   2 , Xiaolei Han  1   2 , Rui Liu  2 , Yifei Ren  2 , Lin Cong  1   2 , Qinghua Zhang  1   2 , Tingting Hou  1   2 , Lin Song  1   2 , Shi Tang  1   2 , Lin Shi  4   5 , Yishan Luo  4 , Grégoria Kalpouzos  3 , Erika J Laukka  3 , Bengt Winblad  3 , Yongxiang Wang  1   2 , Yifeng Du  1   2 , Chengxuan Qiu  1   3
Affiliations

Anosmia, mild cognitive impairment, and biomarkers of brain aging in older adults

Yi Dong et al. Alzheimers Dement. 2023 Feb.

Abstract

Olfactory impairment is a potential marker for prodromal dementia, but the underlying mechanisms are poorly understood. This population-based study included 4214 dementia-free participants (age ≥65 years). Olfaction was assessed using the 16-item Sniffin' Sticks identification test. In the subsamples, we measured plasma amyloid beta (Aβ)40, Aβ42, total tau, and neurofilament light chain (NfL; n = 1054); and quantified hippocampal, entorhinal cortex, and white matter hyperintensity (WMH) volumes, and Alzheimer's disease (AD)-signature cortical thickness (n = 917). Data were analyzed with logistic and linear regression models. In the total sample, mild cognitive impairment (MCI) was diagnosed in 1102 persons (26.2%; amnestic MCI, n = 931; non-amnestic MCI, n = 171). Olfactory impairment was significantly associated with increased likelihoods of MCI, amnestic MCI, and non-amnestic MCI. In the subsamples, anosmia was significantly associated with higher plasma total tau and NfL concentrations, smaller hippocampal and entorhinal cortex volumes, and greater WMH volume, and marginally with lower AD-signature cortical thickness. These results suggest that cerebral neurodegenerative and microvascular lesions are common neuropathologies linking anosmia with MCI in older adults.

Keywords: brain aging; mild cognitive impairment; neurodegeneration; olfaction; population-based study; white matter hyperintensity.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

REFERENCES

    1. Petersen RC. Mild cognitive impairment as a diagnostic entity. J Intern Med. 2004;256(3):183-194.
    1. Knopman DS, Amieva H, Petersen RC, et al. Alzheimer disease. Nat Rev Dis Primers. 2021;7(1):33.
    1. Ubeda-Banon I, Saiz-Sanchez D, Flores-Cuadrado A, et al. The human olfactory system in two proteinopathies: Alzheimer's and Parkinson's diseases. Transl Neurodegener. 2020;9(1):22.
    1. Braak H, Alafuzoff I, Arzberger T, Kretzschmar H, Del Tredici K. Staging of Alzheimer disease-associated neurofibrillary pathology using paraffin sections and immunocytochemistry. Acta Neuropathol. 2006;112(4):389-404.
    1. Lowe VJ, Bruinsma TJ, Wiste HJ, et al. Cross-sectional associations of tau-PET signal with cognition in cognitively unimpaired adults. Neurology. 2019;93(1):e29-e39.

LinkOut - more resources