Table 1 Baseline characteristics of UK Biobank target sample (N = 331,066) according to dementia status.
Characteristics | All | Without dementia | With dementia |
|---|---|---|---|
(n = 331,066) | (n = 327,753) | (n = 3,313) | |
Socio-demographics and lifestyle factors | |||
Men | 158,460 (48) | 156,534 (48) | 1,926 (58) |
Mean (SD) age (years) | 56.14 (8.08) | 56.06 (8.07) | 64.19 (4.63) |
Ethnicity | |||
White | 317,813 (96) | 314,601 (96) | 3,212 (97) |
Non-white | 13,253 (4) | 13,152 (4) | 101 (3) |
Highest educational qualification | |||
Other professional | 16,891 (5) | 16,672 (5) | 219 (7) |
NVQ/HND/HNC | 21,908 (7) | 21,643 (7) | 265 (8) |
CSEs | 17,649 (5) | 17,580 (5) | 69 (2) |
O levels/GCSEs | 71,338 (22) | 70,698 (22) | 640 (19) |
A levels/AS levels | 39,036 (12) | 38,703 (12) | 333 (10) |
College or University degree | 117,357 (35) | 116,571 (36) | 786 (24) |
Less than high school | 46,887 (14) | 45,886 (14) | 1,001 (30) |
Employment status | |||
Employed or self-employed | 190,851 (58) | 190,121 (58) | 730 (22) |
Retired | 116,582 (35) | 114,216 (35) | 2,366 (71) |
Others | 23,633 (7) | 23,416 (7) | 217 (7) |
Household income | |||
< £18,000 | 70,300 (21) | 68,825 (21) | 1,475 (45) |
£18,000–£30,999 | 83,761 (25) | 82,712 (25) | 1,049 (32) |
£31,000–£51,999 | 88,216 (27) | 87,704 (27) | 512 (15) |
£52,000–£100,000 | 70,126 (21) | 69,896 (21) | 230 (7) |
≥ £100,000 | 18,663 (6) | 18,616 (6) | 47 (1) |
Healthy diet | 147,260 (44) | 145,752 (44) | 1,508 (46) |
Not frequent alcohol consumer | 259,604 (78) | 257,058 (78) | 2,546 (77) |
Not current smoker | 297,202 (90) | 294,253 (90) | 2,949 (89) |
Healthy lifestyle score | |||
0–1 | 62,371 (19) | 61,709 (19) | 662 (20) |
2 | 157,680 (48) | 156,148 (48) | 1,532 (46) |
3 | 111,015 (34) | 109,896 (34) | 1,119 (34) |
Social activities | |||
None | 97,533 (29) | 96,519 (29) | 1,014 (31) |
One or more | 233,533 (71) | 231,234 (71) | 2,299 (69) |
Clinical phenotypes | |||
Abdominal obesitya | |||
Obese | 162,259 (49) | 160,177 (49) | 2,082 (63) |
Mean (SD) waist circumference (cm) | 90.27 (13.34) | 90.23 (13.34) | 93.62 (13.43) |
Mean (SD) Hip circumference (cm) | 103.31 (9.03) | 103.31 (9.03) | 103.51 (9.18) |
Frailty | |||
Frail/pre-frail | 131,250 (40) | 129,440 (39) | 1,810 (55) |
Weight change compared with 1 year age | |||
Weight-loss | 50,552 (15) | 49,918 (15) | 634 (19) |
Grip strength | |||
Low grip strength | 42,408 (13) | 41,552 (13) | 856 (26) |
Gait speed | |||
Low gait speed | 22,920 (7) | 22,332 (7) | 588 (18) |
Exhaustion | |||
More than half the days/nearly everyday | 38,490 (12) | 38,014 (12) | 476 (14) |
Physical activities | |||
Low physical activity | 26,081 (8) | 25,690 (8) | 391 (12) |
Hearing difficulty | |||
Deaf or having difficulty with hearing | 84,430 (26) | 83,229 (25) | 1,201 (36) |
Mean (SD) Leucocyte telomere lengthb | 0.01 (1.00) | 0.01 (1.00) | − 0.28 (0.98) |
Mean (SD) C-reactive protein (mg/L) | 2.51 (4.23) | 2.51 (4.22) | 2.79 (4.64) |
Comorbidities at baseline | |||
Cancer | 19,756 (6) | 19,497 (6) | 259 (8) |
Cardiovascular disease | 46,703 (14) | 45,733 (14) | 970 (29) |
Diabetes | 15,928 (5) | 15,448 (5) | 480 (14) |
Hypertension | 94,283 (28) | 92,655 (28) | 1,628 (49) |
Psychiatric disorder | 38,738 (12) | 38,303 (12) | 435 (13) |
Respiratory disease | 71,676 (22) | 70,857 (22) | 819 (25) |
Neighbourhood environment | |||
Urbanicity | |||
Tertile 1 (least urbanized) | 68,666 (21) | 68,107 (21) | 559 (17) |
Tertile 2–4 | 197,630 (60) | 195,536 (60) | 2,094 (63) |
Tertile 5 (most urbanized) | 64,770 (20) | 64,110 (20) | 660 (20) |
Townsend deprivation index | |||
Tertile 1 (least deprived) | 69,809 (21) | 69,142 (21) | 667 (20) |
Tertiles 2–4 | 203,052 (61) | 201,127 (61) | 1,925 (58) |
Tertile 5 (most deprived) | 58,205 (18) | 57,484 (18) | 721 (22) |
