Table 1.
Characteristics on recruitment to the UK Biobank stratified by serum bilirubin level
| Characteristic | Quarter 1 (n=109 514) | Quarter 2 (n=109 514) | Quarter 3 (n=109 514) | Quarter 4 (n=109 514) |
| Serum bilirubin, µmol/L (interquartile range) | 5.5 (4.9 to 6.0) | 7.2 (6.8 to 7.7) | 9.1 (8.6 to 9.7) | 12.9 (11.4 to 16.1) |
| Risk alleles for Gilbert syndrome: | ||||
| None | 73 977 (68) | 60 913 (56) | 47 903 (44) | 21 874 (20) |
| One (heterozygote) | 34 920 (32) | 47 065 (43) | 57 205 (52) | 50 458 (46) |
| Two (homozygote) | 617 (1) | 1536 (1) | 4406 (4) | 37 182 (34) |
| Sex: | ||||
| Female | 82 487 (75) | 66 031 (60) | 50 355 (46) | 38 653 (35) |
| Male | 27 027 (25) | 43 483 (40) | 59 159 (54) | 70 861 (65) |
| Age on recruitment | 58 (51 to 64) | 59 (51 to 64) | 59 (51 to 64) | 58 (50 to 64) |
| Townsend deprivation index | −2.05 (−3.58 to 0.67) | −2.26 (−3.69 to 0.25) | −2.33 (−3.73 to 0.13) | −2.38 (−3.77 to 0.03) |
| Unknown | 121 | 126 | 127 | 139 |
| Alcohol intake frequency: | ||||
| Daily or almost daily | 17 068 (16) | 22 358 (20) | 25 821 (24) | 26 942 (25) |
| Three or four times a week | 21 877 (20) | 25 483 (23) | 28 063 (26) | 28 912 (26) |
| Once or twice a week | 29 340 (27) | 29 076 (27) | 28 331 (26) | 28 171 (26) |
| One to three times a month | 14 667 (13) | 12 642 (12) | 11 109 (10) | 10 435 (10) |
| Special occasions only | 16 345 (15) | 12 178 (11) | 9861 (9) | 9046 (8) |
| Never | 10 032 (9) | 7623 (7) | 6213 (6) | 5867 (5) |
| Prefer not to answer | 116 (0.1) | 87 (<0.1) | 65 (<0.1) | 88 (<0.1) |
| Smoking status: | ||||
| Current | 16 153 (15) | 11 946 (11) | 9859 (9.0) | 7761 (7) |
| Previous | 36 223 (33) | 38 916 (36) | 40 157 (37) | 40 096 (37) |
| Never | 56 622 (52) | 58 190 (53) | 59 065 (54) | 61 230 (56) |
| Prefer not to answer | 447 (<1) | 395 (<1) | 382 (<1) | 374 (<1) |
| Body mass index | 27.1 (24.3 to 30.6) | 26.7 (24.1 to 29.9) | 26.6 (24.1 to 29.6) | 26.5 (24.0 to 29.4) |
| Creatinine (µmol/L) | 66 (58 to 75) | 69 (61 to 79) | 72 (63 to 82) | 75 (66 to 84) |
| History of any liver disease | 2909 (3) | 2632 (2) | 2763 (3) | 3245 (3) |
Data are number (percentage), unless otherwise specified. All P values for comparison were <0.001. Not all characteristics were available for all participants.