TABLE 1.
Baseline characteristics of participants stratified by dementia status in the UK Biobank cohort study1
| All participants (n = 493,888) | Incident dementia (n = 2896) | No dementia (n = 490,992) | |
|---|---|---|---|
| Age at baseline, y | 56.5 ± 8.1 | 63.7 ± 5.5 | 56.5 ± 8.1 |
| Duration of follow-up, y | 8.0 ± 1.1 | 5.9 ± 2.1 | 8.0 ± 1.1 |
| Gender | |||
| Men | 224,691 (45.5%) | 1625 (56.1%) | 223,066 (45.4%) |
| Women | 269,197 (54.5%) | 1271 (43.9%) | 267,926 (54.6%) |
| Ethnicity | |||
| White | 466,835 (94.5%) | 2757 (95.2%) | 464,078 (94.5%) |
| Asian | 10,737 (2.2%) | 44 (1.5%) | 10,693 (2.2%) |
| Black | 7454 (1.5%) | 52 (1.8%) | 7402 (1.5%) |
| Mixed | 2951 (0.6%) | 13 (0.4%) | 2938 (0.6%) |
| Others/unknown | 5911 (1.2%) | 30 (1.0%) | 5881 (1.2%) |
| Region | |||
| England | 438,178 (88.7%) | 2510 (86.7%) | 435,668 (88.7%) |
| Wales | 20,505 (4.2%) | 121 (4.2%) | 20,384 (4.2%) |
| Scotland | 35,205 (7.1%) | 265 (9.2%) | 34,940 (7.1%) |
| Townsend deprivation index | |||
| Low deprivation | 164,443 (33.3%) | 858 (29.6%) | 163,585 (33.3%) |
| Moderate deprivation | 164,409 (33.3%) | 876 (30.2%) | 163,533 (33.3%) |
| High deprivation | 164,426 (33.3%) | 1160 (40.1%) | 163,266 (33.3%) |
| Unknown | 610 (0.1%) | 2 (0.1%) | 608 (0.1%) |
| Educational level | |||
| Without college/university degree | 327,638 (66.3%) | 2245 (77.5%) | 325,393 (66.3%) |
| With college/university degree | 161,496 (32.7%) | 582 (20.1%) | 160,914 (32.8%) |
| Unknown | 4754 (1.0%) | 69 (2.4%) | 4685 (1.0%) |
| Smoking status | |||
| Never | 269,599 (54.6%) | 1273 (44.0%) | 268,326 (54.6%) |
| Past | 170,941 (34.6%) | 1233 (42.6%) | 169,708 (34.6%) |
| Current | 51,734 (10.5%) | 371 (12.8%) | 51,363 (10.5%) |
| Unknown | 1614 (0.3%) | 19 (0.7%) | 1595 (0.3%) |
| Physical activity level | |||
| Low | 75,335 (15.3%) | 478 (16.5%) | 74,857 (15.2%) |
| Moderate | 162,588 (32.9%) | 882 (30.5%) | 161,706 (32.9%) |
| High | 160,784 (32.6%) | 779 (26.9%) | 160,005 (32.6%) |
| Unknown | 95,181 (19.3%) | 757 (26.1%) | 94,424 (19.2%) |
| BMI, kg/m2 | |||
| Normal/underweight (<25) | 162,906 (33.0%) | 893 (30.8%) | 162,013 (33.0%) |
| Overweight (25–29.9) | 208,812 (42.3%) | 1184 (40.9%) | 207,628 (42.3%) |
| Obese (≥30) | 119,702 (24.2%) | 775 (26.8%) | 118,927 (24.2%) |
| Unknown | 2468 (0.5%) | 44 (1.5%) | 2424 (0.5%) |
| Sleep duration | |||
| <7 h/d | 120,987 (24.5%) | 750 (25.9%) | 120,237 (24.5%) |
| 7–8 h/d | 332,852 (67.4%) | 1687 (58.3%) | 331,165 (67.4%) |
| >8 h/d | 37,564 (7.6%) | 415 (14.3%) | 37,149 (7.6%) |
| Unknown | 2485 (0.5%) | 44 (1.5%) | 2441 (0.5%) |
| With stroke history | 7397 (1.5%) | 177 (6.1%) | 7220 (1.5%) |
| With family history of dementia | 57,728 (11.7%) | 558 (19.3%) | 57,170 (11.6%) |
| APOE ε4 carrying status | |||
| Noncarriers | 290,382 (58.8%) | 1177 (40.6%) | 289,205 (58.9%) |
| Carriers | 115,873 (23.5%) | 1182 (40.8%) | 114,691 (23.4%) |
| Missing | 87,633 (17.7%) | 537 (18.5%) | 87,096 (17.7%) |
| Total meat | |||
| Never | 20,473 (4.1%) | 94 (3.2%) | 20,379 (4.2%) |
| ≤3 times/wk | 77,261 (15.6%) | 459 (15.8%) | 76,802 (15.6%) |
| 3–5 times/wk | 90,065 (18.2%) | 509 (17.6%) | 89,556 (18.2%) |
| ≥5 times/wk | 162,570 (32.9%) | 875 (30.2%) | 161,695 (32.9%) |
| ≥7 times/wk | 143,519 (29.1%) | 959 (33.1%) | 142,560 (29.0%) |
| Vegetables/fruits | |||
| <2 servings/d | 28,960 (5.9%) | 194 (6.7%) | 28,766 (5.9%) |
| <4 servings/d | 133,350 (27.0%) | 638 (22.0%) | 132,712 (27.0%) |
| 4–6 servings/d | 190,853 (38.6%) | 1032 (35.6%) | 189,821 (38.7%) |
| >6 servings/d | 128,487 (26.0%) | 893 (30.8%) | 127,594 (26.0%) |
| Unknown | 12,238 (2.5%) | 139 (4.8%) | 12,099 (2.5%) |
| Total fish | |||
| ≤1 times/wk | 126,980 (25.7%) | 678 (23.4%) | 126,302 (25.7%) |
| 1–2 times/wk | 107,219 (21.7%) | 520 (18.0%) | 106,699 (21.7%) |
| ≥2 times/wk | 150,200 (30.4%) | 865 (29.9%) | 149,335 (30.4%) |
| ≥4 times/wk | 106,331 (21.5%) | 791 (27.3%) | 105,540 (21.5%) |
| Unknown | 3158 (0.6%) | 42 (1.5%) | 3116 (0.6%) |
| Alcohol | |||
| <1 time/wk | 150,575 (30.5%) | 1075 (37.1%) | 149,500 (30.4%) |
| 1–2 times/wk | 127,529 (25.8%) | 664 (22.9%) | 126,865 (25.8%) |
| 3–4 times/wk | 114,501 (23.2%) | 536 (18.5%) | 113,965 (23.2%) |
| Daily or almost daily | 100,944 (20.4%) | 610 (21.1%) | 100,334 (20.4%) |
| Unknown | 339 (0.1%) | 11 (0.4%) | 328 (0.1%) |
| Tea/coffee | |||
| ≤3 cups/d | 108,836 (22.0%) | 663 (22.9%) | 108,173 (22.0%) |
| ≤5 cups/d | 161,965 (32.8%) | 918 (31.7%) | 161,047 (32.8%) |
| ≤7 cups/d | 132,660 (26.9%) | 698 (24.1%) | 131,962 (26.9%) |
| >7 cups/d | 88,987 (18.0%) | 593 (20.5%) | 88,394 (18.0%) |
| Unknown | 1440 (0.3%) | 24 (0.8%) | 1416 (0.3%) |
1Continues variables displayed as means ± SDs, and categorical variables are displayed as numbers (percentages). APOE, apolipoprotein E.