Table 1.
Sample characteristics according to 24-hour sleep duration (hours/day)
| Men (n=2,438) | Women (n=3,326) | |||||||
|---|---|---|---|---|---|---|---|---|
|
| ||||||||
| < 6 h (n=257) | 6–8 h (n=1,789) | > 8 h (n=392) | p-value | < 6 h (n=569) | 6–8 h (n=2,338) | > 8h (n=419) | p-value | |
| Mean ± SE | ||||||||
| Age, years | 76.8 ± 0.4a | 76.7 ± 0.1a | 78.6 ± 0.3 | <0.001 | 77.0 ± 0.3a | 76.8 ± 0.1a | 78.1 ± 0.4 | 0.001 |
| Weight, kg | 83.5 ± 0.8 | 82.5 ± 0.3 | 82.4 ± 0.7 | 0.44 | 70.0 ± 0.6 | 69.9 ± 0.3 | 71.0 ± 0.7 | 0.26 |
| Height, cm | 175.4 ± 0.4 | 175.3 ± 0.2 | 174.7 ± 0.4 | 0.07 | 160.5 ± 0.3 | 160.6 ± 0.1 | 159.9 ± 0.3 | 0.06 |
| BMI, kg/m2 | 27.1 ± 0.2 | 26.8 ± 0.1 | 26.9 ± 0.2 | 0.30 | 27.1 ± 0.2 | 27.1 ± 0.1 | 27.7 ± 0.3 | 0.07 |
| Thigh muscle lean area, cm2 | 127.6 ± 1.3a | 126.9 ± 0.5a | 122.9 ± 1.2 | <0.001 | 91.7 ± 0.7 a | 91.7 ± 0.4a | 89.2 ± 0.9 | 0.02 |
| Thigh muscle attenuation, HU | 41.2 ± 0.4 | 41.9 ± 0.1a | 40.6 ± 0.3 | <0.001 | 38.6 ± 0.2a | 38.8 ± 0.1a | 37.3 ± 0.3 | <0.001 |
| Integral vBMD, mg/cm3 | 251.9 ± 3.3a | 247.7 ± 1.2 | 242.5 ± 2.5 | 0.03 | 225.6 ± 2.0 | 226.3 ± 0.001 | 220.5 ± 2.7 | 0.06 |
| cvol/ivol | 0.36 ± 0.003a | 0.36 ± 0.001 | 0.35 ± 0.003 | 0.03 | 0.35 ± 0.002 | 0.35 ± 0.001 | 0.34 ± 0.003 | 0.06 |
| # of medical conditions | 2.2 ± 0.1 | 2.0 ± 0.1a | 2.2 ± 0.1 | 0.03 | 2.4 ± 0.06 | 2.3 ± 0.1a | 2.4 ± 0.1 | 0.02 |
| 25OHD, nmol/L | 55.2 ± 1.6 | 57.1 ± 0.6 | 55.0 ± 1.3 | 0.21 | 51.0 ± 1.1 | 51.3 ± 0.5 | 49.4 ± 1.2 | 0.35 |
| Hs-CRP, mg/L | 4.2 ± 0.5 | 3.7 ± 0.2 | 4.4 ± 0.4 | 0.19 | 3.7 ± 0.4 | 3.8 ± 0.2 | 4.8 ± 0.5 | 0.06 |
| n (%) | ||||||||
| Current Smoker | 15 (5.8) | 101 (5.6) | 27 (6.9) | 0.60 | 53 (9.3) | 282 (12.1) | 70 (16.7) | 0.003 |
| High PA level status | 49 (19.1) | 387 (21.6) | 52 (13.3) | 0.001 | 84 (14.8) | 332 (14.2) | 29 (6.9) | <0.001 |
| Poor health status | 93 (36.2) | 491 (27.4) | 162 (41.3) | <0.001 | 233 (40.9) | 842 (36.0) | 198 (47.3) | <0.001 |
| Mobility disability | 29 (11.3) | 127 (7.1) | 67 (17.1) | <0.001 | 103 (18.1) | 349 (14.9) | 121 (28.9) | <0.001 |
| Depressive symptoms | 21 (8.2) | 103 (5.8) | 56 (14.3) | <0.001 | 56 (9.8) | 186 (8.0) | 58 (13.8) | 0.006 |
| Dementia | 15 (5.8) | 111 (6.2) | 78 (19.9) | <0.001 | 30 (5.3) | 149 (6.4) | 69 (16.5) | <0.001 |
| Use of oral glucocorticoid or antiepileptics | 9 (3.5) | 80 (4.5) | 13 (3.3) | 0.35 | 27 (4.7) | 113 (4.8) | 29 (6.9) | 0.46 |
| Use of anti-bone loss drugs | 14 (3.9) | 99 (5.5) | 20 (5.1) | 0.80 | 151 (26.5) | 571 (24.4) | 91 (21.7) | 0.30 |
| Use of antidepressants | 24 (9.3) | 181 (10.1) | 92 (23.5) | <0.001 | 80 (14.1) | 398 (17.0) | 143 (34.1) | <0.001 |
| Use of psycholeptics | 34 (13.2) | 208 (11.6) | 40 (10.2) | 0.48 | 133 (23.4) | 458 (19.6) | 90 (21.5) | 0.25 |
| Coffee consumption | 144 (56.0) | 999 (55.8) | 202 (51.5) | 0.42 | 270 (47.5) | 1240 (53.0) | 209 (49.9) | 0.06 |
| Light to moderate alcohol consumption | 170 (66.1) | 1251 (69.9) | 258 (65.8) | 0.03 | 321 (56.4) | 1341 (57.4) | 209 (49.9) | 0.26 |
a
Significantly different from longer sleep group (>8h/day);
b
Significantly different from shorter sleep group (<6h/day) BMI = body mass index, cvol/ivol = cortical volume integral volume PA= physical activity, Hs-CRP = high-sensitivity C-reactive protein.