Table 1.
Participant characteristics.
| ALL | Q1 | Q2 | Q3 | Q4 | P-value | |
|---|---|---|---|---|---|---|
| Range of olfactory score | 0–6 | 0–1 | 2 | 3–4 | 5–6 | |
| Number of samples | 1444 | 428 | 245 | 469 | 302 | |
| Age, years | 63.4 ± 9.8 | 68.4 ± 8.6 | 64.5 ± 9.1 | 61.5 ± 9.4 | 58.2 ± 8.9 | < 0.001 |
| Men, n (%) | 521 (36.1) | 195 (45.6) | 111 (45.3) | 137 (29.2) | 78 (25.8) | < 0.001 |
| Education, years | 13.5 ± 1.8 | 13.3 ± 1.9 | 13.5 ± 1.8 | 13.6 ± 1.7 | 13.6 ± 1.7 | 0.010 |
| Smoking ever, n (%) | 542 (37.5) | 165 (38.6) | 105 (42.9) | 156 (33.3) | 116 (38.4) | 0.355 |
| MoCA-J score | 25.6 ± 2.6 | 24.7 ± 2.7 | 25.5 ± 2.5 | 26.1 ± 2.5 | 26.4 ± 2.2 | < 0.001 |
| ICV-normalised GMV for brain (× 10−3) | 402.9 ± 35.6 | 390.3 ± 34.9 | 399.6 ± 35.7 | 407.6 ± 34.2 | 416.0 ± 32.9 | < 0.001 |
Continuous data are presented as mean ± standard deviation. Categorical data are presented as number (percentage). The olfactory score is the total score for spearmint and stuffy socks. The MoCA-J is the Japanese version of the Montreal Cognitive Assessment. The ICV-normalised GMV represents the ratio of grey matter volume to intracranial volume. P-values were derived using the Jonckheere–Terpstra and Cochran–Armitage tests for trends in the distributions of continuous and categorical variables, respectively.