Table 1. Baseline characteristics of study participants by sleep duration among men.
| Characteristics | Overall | Sleep duration (hours) | P for quadratic trend | ||||
|---|---|---|---|---|---|---|---|
| ≤ 5 | 6 | 7 | 8 | ≥ 9 | |||
| Number | 135,633 | 21,081 | 55,249 | 45,242 | 12,533 | 1,528 | |
| Age (years)a | 41.0 (9.0) | 40.7 (8.9) | 40.6 (8.2) | 41.0 (9.0) | 42.5 (10.9) | 46.2 (14.3) | <0.001 |
| Seoul center (%) | 66.3 | 72.0 | 67.5 | 63.0 | 63.0 | 65.8 | <0.001 |
| Obesity (%) | 39.4 | 44.5 | 40.0 | 37.2 | 36.1 | 36.8 | <0.001 |
| Current smoker (%) | 38.6 | 42.8 | 38.4 | 37.3 | 37.2 | 39.0 | 0.136 |
| Alcohol intake (%)b | 36.7 | 40.8 | 36.9 | 34.8 | 35.2 | 39.0 | 0.119 |
| HEPA (%) | 17.6 | 18.0 | 17.3 | 17.4 | 18.6 | 20.6 | <0.001 |
| High education (%)d | 86.8 | 87.0 | 89.2 | 87.0 | 78.8 | 58.5 | <0.001 |
| Married (%) | 81.0 | 76.1 | 80.9 | 82.7 | 83.6 | 78.5 | <0.001 |
| Depression (%) | 7.8 | 12.9 | 7.4 | 6.1 | 6.6 | 11.4 | 0.196 |
| Hypertension | 16.5 | 17.3 | 16.0 | 16.0 | 18.2 | 24.4 | <0.001 |
| Diabetes | 6.1 | 6.8 | 5.5 | 5.8 | 7.4 | 12.8 | <0.001 |
| History of CVD | 1.6 | 1.7 | 1.4 | 1.5 | 2.2 | 4.1 | <0.001 |
| BMI (kg/m2) | 24.5 (2.9) | 24.8 (3.0) | 24.5 (2.9) | 24.3 (3.0) | 24.2 (3.0) | 24.2 (3.1) | <0.001 |
| Systolic BP (mmHg)a | 114.6 (11.7) | 114.7 (11.8) | 114.4 (11.6) | 114.5 (11.7) | 115.0 (12.0) | 116.3 (12.8) | <0.001 |
| Diastolic BP (mmHg)a | 74.0 (9.4) | 74.0 (9.7) | 73.9 (9.4) | 74.0 (9.4) | 74.2 (9.3) | 74.8 (9.9) | <0.001 |
| Glucose (mg/dl)a | 98.4 (16.5) | 98.7 (18.1) | 98.1 (15.8) | 98.4 (16.4) | 99.2 (16.6) | 101.9 (22.0) | <0.001 |
| Total cholesterol (mg/dl)a | 200.0 (34.6) | 200.6 (35.2) | 200.2 (34.4) | 199.6 (34.2) | 199.6 (35.5) | 198.8 (36.1) | 0.028 |
| LDL-C (mg/dl)a | 127.4 (31.4) | 127.5 (31.7) | 127.6 (31.3) | 127.2 (31.2) | 127.2 (32.0) | 126.9 (32.5) | 0.159 |
| HDL-C (mg/dl)a | 52.8 (12.7) | 52.8 (12.9) | 52.9 (12.7) | 52.8 (12.7) | 52.5 (12.8) | 51.5 (12.8) | <0.001 |
| Triglycerides (mg/dl)c | 115 (81–165) | 117 (82–169) | 114 (81–194) | 114 (81–163) | 115 (81–165) | 121 (84–176) | 0.002 |
| ALT (U/l)c | 23 (17–34) | 24 (17–35) | 23 (17–34) | 23 (17–34) | 24 (17–34) | 24 (17–35) | 0.051 |
| HOMA-IRc | 1.28 (0.84–1.92) | 1.29 (0.84–1.97) | 1.27 (0.83–1.89) | 1.28 (0.84–1.92) | 1.32 (0.86–1.97) | 1.35 (0.85–2.09) | <0.001 |
| hsCRP (mg/l)c | 0.5 (0.3–1.0) | 0.6 (0.3–1.1) | 0.5 (0.3–1.0) | 0.5 (0.3–1.0) | 0.5 (0.3–1.1) | 0.6 (0.3–1.2) | <0.001 |
| Total energy intakec,e | 1667.5 (1348.6–2056.4) | 1678.6 (1330.8–2093.3) | 1667.9 (1353.7–2053.3) | 1663.7 (1350.0–2042.7) | 1661.3 (1345.8- | 1673.2 (1344.9–2064.9) | 0.368 |
| Poor sleep quality | 14.8 | 32.9 | 14.9 | 8.5 | 6.6 | 10.0 | <0.001 |
Data are expressed as
a mean (standard deviation)
c median (interquartile range), or percentage.
b ≥ 20 g of ethanol per day
d ≥ college graduate
e among 165,861 participants with plausible estimated energy intake levels (within three standard deviations from the log-transformed mean energy intake).
CVD, cardiovascular disease; ALT, alanine aminotransferase; BMI, body mass index; BP, blood pressure; HDL-C, high-density lipoprotein cholesterol; HEPA, health-enhancing physical activity; hsCRP, high sensitivity C-reactive protein; HOMA-IR, homeostasis model assessment of insulin resistance.