Table 1.
Demographic characteristics stratified by total sleep time
| < 5 h (n = 82) | 5-6 h (n = 139) | 6-7 h (n = 205) | 7-8 h (n = 96) | ≥ 8 h (n = 39) | P-value | |
|---|---|---|---|---|---|---|
| Age (yrs) | 55.4 ± 18.0 | 50.2 ± 17.3 | 41.3 ± 15.7 | 38.1 ± 15.3 | 34.0 ± 12.5 | < 0.001 |
| Male gender (%) | 47.6 | 42.0 | 38.5 | 39.6 | 43.6 | 0.65 |
| White race (%) | 51.2 | 41.0 | 44.4 | 40.6 | 28.2 | 0.40 |
| Body mass index (kg/m2) | 33.5 ± 8.1 | 32.4 ± 7.7 | 33.1 ± 8.7 | 31.5 ± 7.7 | 30.2 ± 7.1 | 0.07 |
| Waist Circumference (cm) | 102.7 ± 16.4 | 97.7 ± 18.0 | 98.0 ± 18.1 | 94.9 ± 18.0 | 92.5 ± 16.2 | 0.01 |
| Hypertension (%) | 52.4 | 41.7 | 30.7 | 22.9 | 20.5 | < 0.001 |
| Systolic blood pressure (mm Hg) | 128.7 ± 14.2 | 126.5 ± 15.6 | 122.7 ± 15.6 | 120.4 ± 14.5 | 121.8 ± 16.7 | < 0.001 |
| Diastolic blood pressure (mm Hg) | 75.0 ± 9.5 | 75.0 ± 9.0 | 74.3 ± 9.1 | 73.2 ± 9.4 | 74.2 ± 10.4 | 0.56 |
| Antihypertensive medication usage (%) | 45.1 | 38.1 | 24.4 | 18.8 | 12.8 | < 0.001 |
| Type 2 diabetes (%) | 34.2 | 15.8 | 14.6 | 10.4 | 5.1 | < 0.001 |
| Fasting glucose (mg/dL) | 101.4 ± 25.1 | 97.5 ± 23.4 | 98.4 ± 28.8 | 97.0 ± 24.5 | 91.8 ± 9.9 | 0.09 |
| Antidiabetic medication usage (%) | 18.3 | 9.4 | 5.9 | 5.2 | 0.0 | 0.19 |
| Apnea hypopnea index | 19.2 ± 22.4 | 15.1 ± 21.7 | 15.1 ± 21.6 | 9.2 ± 16.1 | 12.3 ± 22.6 | 0.002 |
| N1 (minutes) | 18.1 ± 12.5 | 21.6 ± 21.5 | 18.2 ± 10.9 | 17.2 ± 10.9 | 21.8 ± 16.6 | 0.06 |
| N2 (minutes) | 142.7 ± 46.1 | 201.6 ± 41.5 | 227.3 ± 41.3 | 242.2 ± 46.5 | 291.5 ± 47.1 | < 0.001 |
| N3 (minutes) | 43.4 ± 33.1 | 57.2 ± 38.9 | 68.8 ± 39.4 | 87.8 ± 43.6 | 82.5 ± 41.9 | < 0.001 |
| REM (minutes) | 38.6 ± 25.2 | 53.2 ± 23.1 | 74.8 ± 25.7 | 96.0 ± 20.9 | 118.1 ± 38.8 | < 0.001 |
Values displayed as mean ± standard deviation or proportion (%).