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. 2022 Apr 1;72(1):8.
doi: 10.1186/s12576-022-00832-6.

Olfactory function and discrimination ability in the elderly: a pilot study

Sae Uchida  1 , Chiho Shimada  2   3 , Naoko Sakuma  4 , Fusako Kagitani  5 , Akiko Kan  6 , Shuichi Awata  7
Affiliations

Olfactory function and discrimination ability in the elderly: a pilot study

Sae Uchida et al. J Physiol Sci. .

Abstract

We recently reported that subjects with a higher olfactory identification threshold for rose odor declined more in attentional ability in the elderly. This study focuses on discrimination ability and olfactory identification threshold in twelve elderly subjects living in a community (age: 80.9 ± 1.6). Olfactory function was assessed by the rose odor identification threshold. We assessed the discrimination ability by distinguishing 5 similar odor pairs. Our results showed that the subjects with a higher olfactory identification threshold (≥ 5) declined more in discrimination ability (14% ± 14%, p = 0.03) compared to those with a lower threshold (≤ 4) (averaged value set at 100%). As discrimination ability is related to the basal forebrain cholinergic system, our results suggest that olfactory impairment links to the decline in cognitive function relating the cholinergic system.

Keywords: Cholinergic system; Cognitive function; Discrimination ability; Elderly people; Odor identification threshold; Olfactory function.

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Conflict of interest statement

The authors declare that they have no conflicts of interest.

Figures

Fig. 1
Fig. 1
Relationship between discrimination ability and odor identification threshold. a Method testing the discrimination ability to distinguish between 5 odor pairs by comparing three bottles and identifying the one with an odd stimulus. b Scatter plot of the relationship between discrimination ability (score) and identification threshold for rose odor in all 12 subjects. The dots represent the values of an individual subject. The double circles (◎) represents overlapping two dots. Spearman's correlation coefficient r with p value. c Comparison of discrimination ability (score) between two groups of different olfactory abilities, that is, low- and high-threshold groups (≤ 4 and ≥ 5, respectively). The horizontal lines and vertical bars show the mean and SEM values in each group. p = 0.03; the significant difference between the low- and high-threshold groups, tested by Mann–Whitney test
See this image and copyright information in PMC

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