Table 1. Summary of characteristics of UK Biobank participants by analysis dataset.
| Variable | Total dataset | Observational analysis | Mendelian randomization |
|---|---|---|---|
| n | 502536 | 481150 | 337484 |
| Age (years) | 67.3 (8.1) | 67 (8.1) | 67.6 (8) |
| Townsend index | -1.3 (3.1) | -1.3 (3.1) | -1.6 (2.9) |
| Sex | |||
| Female | 273402 (54.4) | 267459 (55.6) | 181236 (53.7) |
| Male | 229134 (45.6) | 213691 (44.4) | 156248 (46.3) |
| Region | |||
| England | 445883 (88.7) | 427194 (88.8) | 297645 (88.2) |
| Wales | 20808 (4.1) | 19936 (4.1) | 14824 (4.4) |
| Scotland | 35845 (7.1) | 34020 (7.1) | 25015 (7.4) |
| Ethnic group | |||
| White | 472725 (94.1) | 452534 (94.1) | 337484 (100) |
| Asian or Asian British | 11456 (2.3) | 10847 (2.3) | 0 (0) |
| Black or Black British | 8061 (1.6) | 7863 (1.6) | 0 (0) |
| Mixed or other | 7517 (1.5) | 7279 (1.5) | 0 (0) |
| Don’t know/refused | 2777 (0.6) | 2627 (0.5) | 0 (0) |
| Smoking status | |||
| Never-smoker | 273537 (54.4) | 265259 (55.1) | 183826 (54.5) |
| Current smoker | 52979 (10.5) | 50453 (10.5) | 33977 (10.1) |
| Former smoker | 173070 (34.4) | 162687 (33.8) | 118505 (35.1) |
| No response | 2950 (0.6) | 2751 (0.6) | 1176 (0.3) |
| Drinking status | |||
| Never-drinker | 22388 (4.5) | 21234 (4.4) | 10392 (3.1) |
| Current drinker | 460386 (91.6) | 441728 (91.8) | 315257 (93.4) |
| Former drinker | 18108 (3.6) | 16631 (3.5) | 11543 (3.4) |
| No response | 1654 (0.3) | 1557 (0.3) | 292 (0.1) |
| Drinking frequency | |||
| Daily or almost daily | 101774 (20.3) | 97438 (20.3) | 72270 (21.4) |
| Three or four times a week | 115445 (23) | 111123 (23.1) | 81462 (24.1) |
| Once or twice a week | 129297 (25.7) | 124157 (25.8) | 88747 (26.3) |
| One to three times a month | 55858 (11.1) | 53724 (11.2) | 37367 (11.1) |
| Special occasions only | 58012 (11.5) | 55286 (11.5) | 35411 (10.5) |
| Never | 40648 (8.1) | 38009 (7.9) | 21991 (6.5) |
| No response | 1502 (0.3) | 1413 (0.3) | 236 (0.1) |
| Alcohol (weekly equivalent glasses of wine) | 7.7 (9.4) | 7.7 (9.4) | 8.1 (9.5) |
| Systolic blood pressure (mmHg) | 139.7 (19.7) | 139.7 (19.7) | 140.2 (19.7) |
| Diastolic blood pressure (mmHg) | 82.2 (10.7) | 82.3 (10.7) | 82.2 (10.7) |
| Body mass index (kg/m^2) | 27.4 (4.8) | 27.4 (4.8) | 27.4 (4.7) |
| Waist circumference (cm) | 90.3 (13.5) | 90 (13.4) | 90.3 (13.5) |
| Body fat percentage | 31.5 (8.5) | 31.5 (8.6) | 31.4 (8.5) |
| Cholesterol (mmol/L) | 5.7 (1.1) | 5.7 (1.1) | 5.7 (1.1) |
| LDL (mmol/L) | 3.6 (0.9) | 3.6 (0.9) | 3.6 (0.9) |
| HDL (mmol/L) | 1.4 (0.4) | 1.5 (0.4) | 1.5 (0.4) |
| Triglycerides (mmol/L) | 1.7 (1) | 1.7 (1) | 1.8 (1) |
| HbA1c (mmol/mol) | 36.1 (6.8) | 36 (6.5) | 36 (6.5) |
| Glucose (mmol/L) | 5.1 (1.2) | 5.1 (1.2) | 5.1 (1.2) |
| Type 2 diabetes | 25217 (5) | 22083 (4.6) | 15493 (4.6) |
| Coronary heart disease | 24047 (4.8) | 11297 (2.3) | 16102 (4.8) |
| All stroke | 11785 (2.3) | 6857 (1.4) | 8044 (2.4) |
| Ischemic stroke | 5081 (1) | 3217 (0.7) | 3427 (1) |
| Hemorrhagic stroke | 2814 (0.6) | 1608 (0.3) | 1877 (0.6) |
| Heart failure | 8956 (1.8) | 5128 (1.1) | 5921 (1.8) |
| Atrial fibrillation | 22197 (4.4) | 14292 (3) | 15483 (4.6) |
| Any cardiovascular disease | 52219 (10.4) | 30833 (6.4) | 35499 (10.5) |
| All-cause death | 20284 (4) | 17635 (3.7) | 13700 (4.1) |
| ADH1B status | |||
| Wildtype | 458807 (91.3) | 439084 (91.3) | 322519 (95.6) |
| Carrier | 26534 (5.3) | 25593 (5.3) | 14777 (4.4) |
| Homozygous minor allele | 1979 (0.4) | 1928 (0.4) | 188 (0.1) |
N (%) for categorical variable traits or mean (standard deviation) for quantitative variable traits (in listed units)