Table 1 Baseline demographic, health, and sleep characteristics of middle-aged adults by TST quartile or TIB quartile (n = 3128).
Characteristic | TST | TIB | ||||
|---|---|---|---|---|---|---|
Q1: < 331 min (n = 776) | IQR: 331 to < 414 min (n = 1566) | Q4: ≥ 414 min (n = 786) | Q1: < 400 min (n = 779) | IQR: 400 to < 477 min (n = 1562) | Q4: ≥ 477 min (n = 787) | |
Age, mean (SD), y | 55.0 (6.7) | 54.7 (6.5) | 53.5 (6.6) | 54.3 (6.6) | 54.5 (6.6) | 54.5 (6.5) |
Race, n (%) | ||||||
Caucasian | 599 (77.2) | 1302 (83.1) | 639 (81.3) | 603 (77.4) | 1300 (83.2) | 637 (80.9) |
Other | 177 (22.8) | 264 (16.9) | 147 (18.7) | 176 (22.6) | 262 (16.8) | 150 (19.1) |
Women, n (%) | 358 (46.1) | 772 (49.3) | 513 (65.3) | 373 (47.9) | 790 (50.6) | 480 (61.0) |
Body mass index, mean (SD)a | 29.4 (5.8) | 28.4 (5.3) | 27.8 (5.2) | 29.0 (5.7) | 28.5 (5.4) | 28.1 (5.0) |
Smoking status, n (%) | ||||||
Current | 122 (15.7) | 187 (11.9) | 83 (10.6) | 130 (16.7) | 184 (11.8) | 78 (9.9) |
Former | 313 (40.3) | 656 (41.9) | 303 (38.5) | 322 (41.3) | 633 (40.5) | 317 (40.3) |
Never | 341 (44.0) | 723 (46.2) | 400 (50.9) | 327 (42.0) | 745 (47.7) | 392 (49.8) |
Apnea hypopnea index (4% oxygen desaturation), mean (SD), events/h | 10.9 (14.7) | 8.8 (13.0) | 7.2 (12.2) | 9.8 (13.2) | 9.0 (13.7) | 7.8 (12.5) |
Sleep time with saturated oxygen below 80%, mean (SD), % time | 0.18 (0.97) | 0.23 (2.71) | 0.16 (2.33) | 0.19 (1.56) | 0.23 (2.57) | 0.17 (2.34) |
Stroke, n (%) | 17 (2.2) | 16 (1.0) | 6 (0.8) | 9 (1.2) | 22 (1.4) | 11 (1.4) |
Myocardial infarction, n (%) | 36 (4.6) | 53 (3.4) | 27 (3.4) | 39 (5.0) | 50 (3.2) | 27 (3.4) |
Hypertension, n (%) | 312 (40.2) | 481 (30.7) | 200 (25.4) | 288 (37.0) | 470 (30.1) | 235 (29.9) |
Diabetes, n (%) | 51 (6.6) | 74 (4.7) | 35 (4.5) | 53 (6.8) | 65 (4.2) | 42 (5.3) |
PSG TST, mean (SD), min | 287.5 (38.3) | 374.3 (23.1) | 441.2 (21.6) | 306.1 (47.6) | 374.9 (42.4) | 421.6 (47.2) |
PSG TIB, mean (SD), min | 376.1 (60.9) | 436.3 (37.7) | 487.3 (25.1) | 356.2 (39.4) | 439.4 (21.6) | 501.0 (16.4) |
Sleep Restfulness score (1–5), mean (SD) | 2.6 (1.7) | 2.9 (1.1) | 3.0 (1.1) | 2.9 (1.2) | 2.8 (1.1) | 2.9 (1.1) |
Stage REM sleep, mean (SD), % time | 18.5 (7.1) | 20.6 (5.6) | 22.5 (5.2) | 19.6 (6.7) | 20.6 (6.0) | 21.3 (5.6) |
Physical Functioning Score on SF-36, mean (SD)b | 80.3 (22.4) | 84.8 (19.4) | 85.1 (18.2) | 82.3 (21.3) | 84.3 (19.9) | 84.1 (18.8) |
Antidepressant use, n (%) | 56 (7.2) | 116 (7.4) | 81 (10.3) | 50 (6.4) | 121 (7.7) | 83 (10.5) |
Benzodiazepine use, n (%) | 27 (3.5) | 66 (4.2) | 24 (3.1) | 22 (2.8) | 63 (4.0) | 32 (4.1) |
Epworth Sleepiness Scale score (0–24), mean (SD) | 8.1 (4.6) | 8.1 (4.4) | 7.8 (4.4) | 8.3 (4.7) | 8.1 (4.5) | 7.6 (4.2) |
Number of daytime naps per week, mean (SD) | 2.5 (3.4) | 2.1 (2.9) | 1.8 (3.4) | 2.3 (3.1) | 2.1 (3.2) | 1.9 (3.1) |
Weekend-weekday difference in habitual sleep duration, mean (SD), h | 0.63 (0.99) | 0.60 (0.89) | 0.65 (0.94) | 0.68 (0.97) | 0.61 (0.89) | 0.57 (0.95) |
Insomnia or poor sleep, n (%) | 293 (37.8) | 502 (32.1) | 244 (31.0) | 244 (31.3) | 523 (33.5) | 273 (34.7) |
