Table 1.
Characteristics of the Study Sample
| Variables | Total Sample (n=723) | Sleep Sufficiency (n=317) | Sleep Insufficiency (n=406) | χ2/t value | P value |
|---|---|---|---|---|---|
| Gender | |||||
| Male | 238 (32.9) | 104 (43.7) | 134 (56.3) | 0.003 | 0.955 |
| Female | 485 (67.1) | 213 (43.9) | 272 (56.1) | ||
| Age, mean±SE | 18.68±0.99 | 18.81±1.07 | 18.57±0.90 | 3.257 | 0.001 |
| BMI, mean±SE | 20.73±2.59 | 20.54±2.22 | 20.84±2.84 | −1.752 | 0.080 |
| Residential area | |||||
| Rural | 407 (56.3) | 170 (41.8) | 237 (58.2) | 1.630 | 0.202 |
| Urban | 316 (43.7) | 147 (46.5) | 169 (53.5) | ||
| Any siblings | |||||
| No | 185 (25.6) | 79 (42.7) | 106 (57.3) | 0.132 | 0.717 |
| Yes | 538 (74.4) | 238 (44.2) | 300 (55.8) | ||
| Self-reported family economy | |||||
| Low | 160 (22.1) | 75 (46.9) | 85 (53.1) | 2.040 | 0.361 |
| Medium | 525 (72.6) | 229 (43.6) | 296 (56.4) | ||
| High | 38 (5.3) | ||||
| Self-rated health | |||||
| High | 435 (60.1) | 208 (47.8) | 227 (52.2) | 11.242 | 0.004 |
| Medium | 265 (36.7) | 105 (39.6) | 160 (60.4) | ||
| Low | 23 (3.2) | 4 (17.4) | 19 (82.6) | ||
| Father’s education level | |||||
| Primary school and below | 160 (22.1) | 72 (45.0) | 88 (55.0) | 0.114 | 0.944 |
| Middle school | 350 (48.4) | 152 (43.4) | 198 (56.6) | ||
| Senior high school and above | 213 (29.5) | 93 (43.7) | 120 (56.3) | ||
| Mother’s education level | |||||
| Primary school and below | 322 (44.5) | 140 (43.5) | 182 (56.5) | 1.534 | 0.464 |
| Middle school | 249 (34.5) | 104 (41.8) | 145 (58.2) | ||
| Senior high school and above | 152 (21.0) | 73 (48.0) | 79 (52.0) | ||
| Cigarette use | |||||
| No | 678 (93.8) | 293 (43.2) | 385 (56.8) | 1.755 | 0.185 |
| Yes | 45 (6.2) | 24 (53.3) | 21 (46.7) | ||
| Alcohol use | |||||
| No | 567 (78.4) | 249 (43.9) | 318 (56.1) | 0.005 | 0.942 |
| Yes | 156 (21.6) | 68 (43.6) | 88 (56.4) | ||
| Physical activity | |||||
| High | 212 (29.3) | 49 (42.2) | 67 (57.8) | 16.263 | <0.001 |
| Medium | 395 (54.6) | 151 (38.2) | 244 (61.8) | ||
| Low | 116 (16.1) | 117 (55.2) | 95 (44.8) | ||
| Afternoon napping | |||||
| Yes | 631 (87.3) | 263 (41.7) | 368 (58.3) | 9.442 | 0.002 |
| No | 92 (12.7) | 54 (58.7) | 38 (41.3) | ||
| Depressive symptoms | |||||
| No | 433 (59.9) | 208 (48.0) | 225 (52.0) | 7.704 | 0.006 |
| Yes | 290 (40.1) | 109 (37.6) | 181 (62.4) | ||
| Chronotype | |||||
| M-types | 107 (14.8) | 65 (60.7) | 42 (39.3) | 20.353 | <0.001 |
| N-types | 541 (74.8) | 231 (42.7) | 310 (57.3) | ||
| E-types | 75 (10.4) | 21 (28.0) | 54 (72.0) | ||
| Inflammatory cytokines, mean±SE | |||||
| IL-1β | 0.32±0.26 | 0.27±0.26 | 0.36±0.25 | −4.418 | <0.001 |
| IL-6 | 0.72±0.32 | 0.70±0.34 | 0.74±0.30 | −1.997 | 0.046 |
| TNF-α | 0.77±0.21 | 0.74±0.22 | 0.79±0.20 | −3.549 | <0.001 |
| IL-10 | 1.92±0.31 | 1.86±0.33 | 1.97±0.29 | −4.742 | <0.001 |
Note: Inflammatory factors were log-transformed before analysis.
Abbreviations: SE, Standard Error; BMI, body mass index; M-types, Morning-types; N-types, Neutral -types; E-types, Evening-types; IL-1β, interleukin-1β; IL-6, interleukin-6; TNF-α, tumor necrosis factor-α; IL-10, interleukin-10.