Table 1.
Baseline Characteristics
| Sleep Duration, h/day
|
|||
|---|---|---|---|
| ≥ 6 | 7–8 | ≥ 9 | |
| Participants, no. | 25,672 | 55,449 | 4579 |
| Age, y | 47.0 ± 4.6 | 46.7 ± 4.7 | 46.6 ± 4.7 |
| Alcohol, g/d | 3.5 ± 6.9 | 4.1 ± 7.3 | 4.3 ± 8.5 |
| Smoking, % | 11.2 | 7.6 | 8.4 |
| Caffeine, mg/d | 229 ± 209 | 218 ± 193 | 212 ± 194 |
| Activity, METs/wk | 17.1 ± 23.5 | 17.1 ± 20.5 | 14.8 ± 21.3 |
| Caloric intake, kcal/d | 1802 ± 574 | 1827 ± 552 | 1873 ± 580 |
| Married, % | 74.0 | 81.7 | 78.1 |
| Children at home % | 81.4 | 82.3 | 78.2 |
| Living alone, % | 10.2 | 7.7 | 9.8 |
| Annual income < $50,000, % | 18.3 | 15.2 | 23.7 |
| Currently unemployed, % | 8.2 | 12.5 | 25.6 |
| History of depressive symptoms, % | 53.1 | 49.6 | 64.7 |
| Current depressive symptoms, % | 11.0 | 6.1 | 12.2 |
| Antidepressant use, % | 15.7 | 16.7 | 38.2 |
| Benzodiazepine use, % | 3.6 | 2.8 | 7.8 |
| Obesity, % | 29.0 | 22.0 | 27.9 |
| Diabetes, % | 3.5 | 2.6 | 4.5 |
| Hypothyroidism, % | 12.3 | 10.9 | 15.0 |
| Hyperthyroidism, % | 2.2 | 1.9 | 2.0 |
| Seizure, % | 2.0 | 1.6 | 2.8 |
| Head injury, % | 12.4 | 10.8 | 13.0 |
| Multiple sclerosis, % | 0.9 | 0.8 | 2.8 |
| Stroke, % | 1.0 | 0.7 | 1.5 |
| Coronary disease, % | 2.6 | 1.6 | 3.0 |
| Hypertension, % | 21.2 | 16.7 | 20.7 |
| SLE, % | 0.9 | 0.7 | 1.9 |
| Rheumatoid arthritis, % | 3.2 | 2.4 | 3.7 |
| Osteoarthritis, % | 20.8 | 15.6 | 21.9 |
| Herniated disc, % | 9.2 | 6.8 | 9.1 |
| Asthma, % | 15.9 | 13.2 | 17.4 |
| COPD, % | 2.0 | 1.0 | 2.4 |
| Cancer, % | 5.3 | 5.1 | 6.0 |
| IBD, % | 2.4 | 1.6 | 2.7 |
| Any medical disease, % | 68.4 | 60.6 | 68.8 |
| Pregnant, % | 0.3 | 0.5 | 0.8 |
| Postmenopausal, % | 37.4 | 31.4 | 33.1 |
| Premenstrual syndrome, % | 14.3 | 13.0 | 18.5 |
| Estrogen use, % | 23.4 | 22.4 | 24.0 |
| Restless legs syndrome, % | 2.6 | 1.6 | 3.8 |
| Snoring, % | 7.7 | 6.5 | 10.1 |
| Permanent night shift, % | 13.9 | 7.4 | 9.8 |
| Rotating night shift, % | 9.3 | 5.2 | 5.7 |
Values expressed as percentage or mean ± SD. SLE refers to systemic lupus erythematosus; COPD, chronic obstructive pulmonary disease; IBD, inflammatory bowel disease.