Table 3.
Baseline and metabolic characteristics of all study subjects classified by sleep duration
| Variables | Sleep duration (hours) | |||||
|---|---|---|---|---|---|---|
| ≤5 (n = 793) | 6 (n = 1,284) | 7 (n = 1,372) | 8 (n = 1,164) | ≥9 (n = 362) | P value | |
| Male sex (%) | 240 (39.1) | 535 (52.8) | 567 (52.3) | 470 (49.1) | 137 (41.8) | <0.001 |
| Mean age (yr) | 53.0 ± 0.9 | 44.5 ± 0.6 | 44.0 ± 0.5 | 42.9 ± 0.6 | 43.3 ± 1.3 | <0.001 |
| CVD* (%) | 73 (6.2) | 60 (3.2) | 51 (2.5) | 63 (3.4) | 17 (3.0) | 0.004 |
| SBP (mmHg) | 121.3 ± 0.9 | 117.8 ± 0.6 | 116.8 ± 0.6 | 116.5 ± 0.6 | 116.0 ± 1.0 | <0.001 |
| DBP (mmHg) | 76.3 ± 0.6 | 76.3 ± 0.5 | 76.1 ± 0.4 | 75.3 ± 0.5 | 72.9 ± 0.9 | 0.005 |
| Total cholesterol (mg/dL) | 190.2 ± 1.7 | 187.9 ± 1.4 | 190.2 ± 1.4 | 186.1 ± 1.3 | 187.3 ± 3. 3 | 0.126 |
| Triglyceride (mg/dL) | 133.3 ± 5.1 | 129.5 ± 3.3 | 135.0 ± 4.4 | 129.4 ± 4.8 | 135.0 ± 7.0 | 0.748 |
| FPG (mg/dL) | 99.3 ± 0.9 | 96.3 ± 0.7 | 97.4 ± 0.8 | 96.3 ± 0.8 | 95.3 ± 1.2 | 0.018 |
| Obesity (%) | 277 (34.2) | 428 (33.3) | 422 (32.5) | 333 (29.5) | 104 (28.9) | 0.303 |
| Current smoking (%) | 80 (16.1) | 202 (22.8) | 233 (23.1) | 174 (19.1) | 52 (20.7) | 0.081 |
| Physical activity† (%) | 112 (16.2) | 214 (17.5) | 239 (20.4) | 168 (15.1) | 51 (17.3) | 0.120 |
Values are presented as means ± SD or frequencies (%). P-value for sleep duration category.
*CVD included myocardial infarction, angina, and stroke.
†Physical activity, moderate exercise at least three times a week.
CVD, cardiovascular disease; SBP, systolic blood pressure; DBP, diastolic blood pressure; FPG, fasting plasma glucose; DM, diabetes mellitus; CKD, chronic kidney disease.