Table 1.
Characteristics of the cohort
| Overall | No shift work | Evening/weekend shift | Night shift | |
|---|---|---|---|---|
| Total participants [n] | 238 661 | 197 597 | 19 768 | 21 234 |
| Mean (SD) age (years) | 52.43 (7.04) | 52.62 (7.05) | 52.19 (7.01) | 50.89 (6.73) |
| Male [n (%)] | 116 507 (48.82) | 93 340 (47.24) | 9649 (48.81) | 13 482 (63.49) |
| Ethnicity [n (%)] | ||||
| White | 223 081 (93.74) | 186 972 (94.89) | 17 777 (90.21) | 18 302 (86.51) |
| Mixed | 1702 (0.72) | 1326 (0.67) | 179 (0.91) | 197 (0.93) |
| South Asian | 5158 (2.17) | 3578 (1.82) | 746 (3.79) | 814 (3.85) |
| Black | 4764 (2.00) | 3010 (1.53) | 575 (2.92) | 1172 (5.54) |
| Chinese | 955 (0.40) | 741 (0.38) | 98 (0.50) | 115 (0.54) |
| Others | 2313 (0.97) | 1423 (0.72) | 331 (1.68) | 555 (2.62) |
| College or university degree [n (%)] | 90 370 (38.20) | 81 179 (41.44) | 4901 (25.02) | 4281 (20.32) |
| Mean (SD) deprivation index | −1.36 (3.00) | −1.53 (2.91) | −0.66 (3.23) | −0.50 (3.32) |
| Mean (SD) years working in current job | 13.61 (10.52) | 13.56 (10.52) | 12.96 (10.20) | 14.63 (10.76) |
| Mean (SD) number of work hours a week | 35.63 (12.63) | 35.07 (12.51) | 36.04 (12.27) | 40.51 (13.00) |
| Walking at work [n (%)] | ||||
| Never/rarely | 84 466 (35.42) | 78 564 (39.79) | 3119 (15.79) | 2779 (13.11) |
| Sometimes | 73 068 (30.64) | 61 866 (31.33) | 5620 (28.46) | 5563 (26.24) |
| Usually | 35 141 (14.74) | 26 324 (13.33) | 3958 (20.04) | 4845 (22.85) |
| Always | 45 786 (19.20) | 30 703 (15.55) | 7051 (35.70) | 8012 (37.79) |
| Heavy manual/physical labour at work [n (%)] | ||||
| Never/rarely | 155 352 (65.14) | 141 538 (71.67) | 7773 (39.36) | 6029 (28.43) |
| Sometimes | 50 986 (21.38) | 35 600 (18.03) | 6985 (35.37) | 8378 (39.51) |
| Usually | 16 293 (6.83) | 10 354 (5.24) | 2498 (12.65) | 3431 (16.18) |
| Always | 15 873 (6.66) | 10 000 (5.06) | 2494 (12.63) | 3369 (15.89) |
| Mean (SD) MET-min per week | 2623.13 (2549.46) | 2442.18 (2408.33) | 3389.44 (2949.94) | 3736.84 (3065.37) |
| Mean (SD) television viewing time | 2.40 (1.32) | 2.37 (1.29) | 2.56 (1.41) | 2.63 (1.47) |
| Mean (SD) portions of fruit/vegetables intake | 2.06 (1.43) | 2.03 (1.38) | 2.09 (1.54) | 2.25 (1.70) |
| Mean (SD) portions of red-meat intake | 28 514 (12.01) | 22 749 (11.56) | 2845 (14.51) | 2904 (13.83) |
| Processed-meat intake >2 times a week [n (%)] | 75 342 (31.62) | 60 666 (30.73) | 6551 (33.26) | 8113 (38.37) |
| No oily-fish intake [n (%)] | 4.03 (2.39) | 4.04 (2.32) | 4.03 (2.60) | 3.96 (2.80) |
| Mean (SD) units of alcohol intake | 17.38 (18.85) | 17.20 (18.27) | 17.30 (20.40) | 19.21 (22.34) |
| Smoking [n (%)] | ||||
| Never | 139 704 (58.69) | 117 216 (59.46) | 10 910 (55.38) | 11 531 (54.51) |
| Previous | 73 664 (30.95) | 61 226 (31.06) | 6162 (31.28) | 6263 (29.61) |
| Current | 24 672 (10.36) | 18 680 (9.48) | 2630 (13.35) | 3360 (15.88) |
| Sleep duration <6 hours [n (%)] | 10 982 (4.62) | 7934 (4.02) | 1190 (6.05) | 1855 (8.81) |
| Number of sleep disturbances [n (%)] | ||||
| 0 | 30 897 (13.12) | 26 075 (13.35) | 2365 (12.16) | 2451 (11.85) |
| 1 | 101 018 (42.89) | 84 973 (43.51) | 8011 (41.17) | 8018 (38.75) |
| 2 | 76 186 (32.35) | 62 696 (32.10) | 6448 (33.14) | 7023 (33.94) |
| 3 | 24 133 (10.25) | 19 076 (9.77) | 2308 (11.86) | 2739 (13.24) |
| 4 | 3279 (1.39) | 2494 (1.28) | 324 (1.67) | 460 (2.22) |
| Mean (SD) BMI (kg/m2) | 27.16 (4.63) | 26.99 (4.57) | 27.68 (4.90) | 28.21 (4.80) |
| Obesity [n (%)] | 53 496 (22.49) | 41 977 (21.31) | 5220 (26.52) | 6279 (29.73) |
| Mean (SD) waist circumference (cm) | 89.42 (13.19) | 88.92 (13.07) | 90.63 (13.65) | 92.95 (13.26) |
| Central obesity [n (%)] | 124 895 (52.48) | 101 381 (51.44) | 11 178 (56.77) | 12 296 (58.18) |
| Mean (SD) handgrip strength (kg) | 32.88 (11.06) | 32.65 (10.99) | 32.33 (11.15) | 35.57 (11.32) |
| Mean (SD) systolic blood pressure (mmHg) | 135.11 (17.77) | 135.02 (17.82) | 135.30 (17.79) | 135.73 (17.26) |
| Mean (SD) LDL cholesterol (mmol/L) | 3.58 (0.82) | 3.58 (0.82) | 3.57 (0.82) | 3.57 (0.83) |
| Mean (SD) lipoprotein(a) (nmol/L) | 48.94 (59.05) | 48.70 (59.00) | 50.15 (59.65) | 49.97 (58.93) |
| Mean (SD) HbA1c (mmol/mol) | 35.18 (6.12) | 35.05 (5.93) | 35.69 (6.65) | 35.93 (7.14) |
| Mean (SD) cystatin C (mg/L) | 0.87 (0.13) | 0.87 (0.13) | 0.88 (0.13) | 0.88 (0.13) |
| Mean (SD) GGT (U/L) | 35.49 (37.71) | 35.02 (37.20) | 36.23 (38.33) | 39.19 (41.35) |
Data presented as mean and SD for continuous variables and as frequency and % for categorical variables. SD, standard deviation; MET, metabolic equivalent of tasks; BMI, body mass index; LDL, low-density lipoprotein; HbA1c, glycated haemoglobin; GGT, gamma-glutamyltransferase.