Table 1. Baseline Characteristics of 9,098 men and women free of pre-existing disease (cardiovascular disease, diabetes, cancer, respiratory disorders) from Phase 1 of the Whitehall II study.
| Total population | Men (N = 6114) | Women (N = 2984) | |||||||
| 7–8 h sleep and no sleep disturbances (N = 3457) | Disturbed sleep only (N = 691) | ≤6 h sleep only (N = 1456) | ≤6 h sleep & disturbed sleep (N = 462) | 7–8 h sleep and no sleep disturbances (N = 1553) | Disturbed sleep only (N = 406) | ≤6 h sleep only (N = 664) | ≤6 h sleep & disturbed sleep (N = 323) | ||
| Deaths, n | 804 | 291 | 46 | 150 | 46 | 124 | 32 | 76 | 29 |
| Baseline age, years | 45 | 44 | 44 | 45 | 44 | 45 | 45 | 47 | 47 |
| Lowest employment grade, n (%) | 1976 (22) | 264 (8) | 41 (6) | 183 (13) | 42 (9) | 766 (49) | 161 (40) | 327 (49) | 156 (48) |
| Married, n (%) | 6776 (74) | 2825 (82) | 567 (82) | 1155 (79) | 361 (78) | 981 (63) | 265 (65) | 389 (58) | 181 (56) |
| White, n (%) | 8190 (90) | 3192 (92) | 661 (96) | 1312 (90) | 420 (91) | 1296 (83) | 365 (90) | 563 (85) | 287 (89) |
| Overweight, n (%) | 3509 (39) | 1257 (36) | 251 (36) | 629 (43) | 206 (45) | 577 (37) | 137 (34) | 281 (42) | 134 (41) |
| Current smoker, n (%) | 4310 (48) | 1643 (49) | 358 (53) | 730 (52) | 232 (51) | 685 (45) | 175 (44) | 304 (47) | 153 (48) |
| Physical inactive, n (%) | 2303 (25) | 602 (17) | 139 (20) | 324 (22) | 96 (21) | 612 (39) | 122 (30) | 252 (38) | 126 (37) |
| High alcohol intake, n (%) | 1381 (15) | 574 (17) | 139 (20) | 274 (19) | 98 (21) | 152 (10) | 46 (12) | 59 (9) | 27 (8) |
| Systolic blood pressure, mmHg | 123 | 125 | 123 | 125 | 125 | 120 | 119 | 122 | 120 |
| Cholesterol, mmol/L | 6.0 | 6.0 | 5.9 | 6.0 | 6.0 | 5.9 | 5.9 | 6.0 | 5.9 |
| Nervous trouble/depression*, n (%) | 617 (9) | 141 (5) | 61 (13) | 75 (7) | 68 (19) | 94 (8) | 41 (14) | 65 (13) | 59 (24) |
* In a subset of the population with full information on this variable (n = 6756).