Table 1.
Characteristics of study participants by olfactory function.
| Characteristicsa |
Total sample, n = 4,514 |
Olfactory function | ||
|---|---|---|---|---|
| Normosmia, | Hyposmia, | Anosmia, | ||
| n = 1,456 | n = 1,593 | n = 1,465 | ||
| Age (years) | 71.1 (4.9) | 69.9 (4.1) | 71.0 (4.7)b | 72.4 (5.4)bc |
| Female sex | 2,559 (56.7) | 802 (55.1) | 891 (55.9) | 866 (59.1)b |
| Education Level | ||||
| Illiteracy | 1,720 (38.1) | 456 (31.3) | 618 (38.8)b | 646 (44.1)bc |
| Elementary school | 2,015 (44.6) | 683 (46.9) | 716 (45.0) | 616 (42.1) |
| Middle school or above | 779 (17.3) | 317 (21.8) | 259 (16.3) | 203 (13.9) |
| GENETIC FACTORS | ||||
| APOE ε4 allele carrier | 704 (16.1) | 226 (16.1) | 269 (17.3) | 209 (14.7) |
| BEHAVIORAL FACTORS | ||||
| Smoking Status | ||||
| Never | 2,883 (63.9) | 925 (63.6) | 1,006 (63.2) | 952 (65.0) |
| Former | 680 (15.1) | 227 (15.6) | 252 (15.8) | 201 (13.7) |
| Current | 950 (21.1) | 303 (20.8) | 335 (21.0) | 312 (21.3) |
| Alcohol Drinking | ||||
| No or occasional | 3,398 (77.1) | 1,067 (75.7) | 1,197 (76.7) | 1,134 (78.9) |
| Light to moderate | 784 (17.8) | 261 (18.5) | 288 (18.5) | 235 (16.4) |
| Heavy | 224 (5.1) | 81 (5.8) | 75 (4.8) | 68 (4.7) |
| Physical inactivity | 1,510 (33.5) | 500 (34.3) | 527 (33.1) | 483 (33.0) |
| METABOLIC FACTORS | ||||
| Hypertension | 2,991 (66.8) | 986 (68.4) | 1,027 (65.0) | 978 (67.3) |
| Diabetes | 658 (14.6) | 216 (14.8) | 234 (14.7) | 208 (14.2) |
| Dyslipidemia | 1,084 (24.0) | 355 (24.4) | 374 (23.5) | 355 (24.2) |
| Body Mass Index (kg/m2) | ||||
| Normal (<24) | 1,839 (41.0) | 526 (36.3) | 658 (41.6)b | 655 (44.9)b |
| Overweight (24–27.9) | 1,752 (39.0) | 585 (40.3) | 611 (38.7) | 556 (38.1) |
| Obesity (≥28) | 898 (20.0) | 339 (23.4) | 312 (19.7) | 247 (16.9) |
| CLINICAL FACTORS | ||||
| Dementia | 142 (3.2) | 11 (0.8) | 42 (2.6)b | 89 (6.1)bc |
| Depressive symptoms | 449 (10.2) | 141 (9.8) | 144 (9.2) | 164 (11.6)c |
| Parkinson's disease | 33 (0.7) | 5 (0.3) | 13 (0.8) | 15 (1.0)b |
| Cardiovascular disease | 1,489 (33.0) | 476 (32.7) | 537 (33.7) | 476 (32.5) |
| Cancer | 61 (1.4) | 16 (1.1) | 23 (1.4) | 22 (1.5) |
| History of Head Injury | ||||
| No | 4,269 (94.7) | 1,397 (96.2) | 1,495 (94.0)b | 1,377 (94.2)b |
| Yes | 237 (5.3) | 56 (3.9) | 96 (6.0) | 85 (5.8) |
| Non-traumatic | 146 (3.2) | 38 (2.6) | 57 (3.6) | 51 (3.5) |
| Traumatic | 91 (2.0) | 18 (1.2) | 39 (2.5) | 34 (2.3) |
| Sinonasal disease | 409 (9.6) | 112 (8.2) | 146 (9.7) | 151 (10.9)b |
| SSIT score | 8.7 (3.2) | 12.2 (1.2) | 9.1 (0.8)b | 5.0 (2.0)bc |
Data are mean (SD) or n (%); SSIT, Sniffin' Sticks Identification Test.
a
The number of participants with missing values was 135 for APOE genotype, 1 for smoking, 108 for drinking, 38 for hypertension, 25 for body mass index, 101 for depressive symptom, 8 for head injury, and 252 for sinonasal disease. As a covariate in subsequent analyses, a dummy variable was created for each of the categorical variables to represent those with missing values.
b
P < 0.05 for the comparison with normosmia.
c
P < 0.05 for the comparison with hyposmia.