Table 1.
Difficulty initiating sleeping | |||
Non | Sometimes | Often | |
No. of subjects (%) | 3993 (61.3) | 1996 (30.7) | 520 (8.0) |
Age * | 38.4 ± 9.5 | 38.3 ± 9.5 | 36.2 ± 9.5 |
Gender (male, %) | 77.7 | 78.6 | 83.0 |
BMI (kg/m2) † ‡ | 22.7 ± 0.05 | 22.7 ± 0.07 | 22.8 ± 0.14 |
Physical activity (MET-h/week) † § | 5.5 ± 0.17 | 4.3 ± 0.24 | 5.1 ± 0.46 |
History of hypercholesterolemia (%) | 7.5 | 7.8 | 8.4 |
History of hypertension (%) | 11.8 | 13.1 | 13.6 |
Smoking (%) | |||
Never | 44.4 | 37.1 | 30.0 |
Past | 15.9 | 12.6 | 14.1 |
Current | 39.7 | 50.3 | 55.9 |
Family history of diabetes (%) | 18.2 | 19.1 | 17.8 |
Sleeping time (hours) (%) | |||
<6 | 14.3 | 16.9 | 30.3 |
6–7 | 41.9 | 44.6 | 42.4 |
7–8 | 34.3 | 31.6 | 21.9 |
8< | 9.5 | 6.9 | 5.4 |
Alcohol intake quartiles (%) | |||
1Q (0 mg/week) | 44.2 | 44.6 | 46.0 |
2Q (0.1–2.5 mg/week) | 1.4 | 1.2 | 1.0 |
3Q (2.6–25.0 mg/week) | 23.8 | 23.1 | 19.0 |
4Q (25.1-mg/week) | 22.2 | 21.0 | 24.5 |
Data missing | 8.4 | 10.1 | 9.5 |
* Plus-minus values are means ± SD
† Plus-minus values are means ± SE
‡ BMI denotes body mass index
§ MET-h denotes metabolic equivalent hours