Table 1.
The general characteristics of study participants according to shift status.
| Variables | Total | Day Work | Night Shift Work | |
|---|---|---|---|---|
| n = 435 | n = 91 | n = 344 | p Value | |
| * Age (years), mean ± SD | 44.1 ± 5.0 | 44.1 ± 5.0 | 44.1 ± 5.0 | 0.937 a |
| Marital status, n (%) | 0.329 b | |||
| Married/Cohabitating | 406 (93.3) | 87 (95.6) | 319 (92.7) | |
| Single/Divorced/Widow | 29 (6.7) | 4 (4.4) | 25 (7.3) | |
| Smoking status, n (%) | 0.036 b | |||
| Nonsmoker | 390 (89.7) | 87 (95.6) | 303 (88.1) | |
| Pre-/Current smoker | 45 (10.3) | 4 (4.4) | 41 (11.9) | |
| Drinking status, n (%) | 0.053 b | |||
| Nondrinker | 399 (91.7) | 88 (96.7) | 311 (90.4) | |
| Pre-/Current drinker | 36 (8.3) | 3 (3.3) | 33 (9.6) | |
| Education level, n (%) | 0.162 b | |||
| High school or below | 339 (77.9) | 66 (72.5) | 273 (79.4) | |
| University or college | 96 (22.1) | 25 (27.5) | 71 (20.6) | |
| Ethnicity, n (%) | 0.018 b | |||
| Han | 413 (94.4) | 82 (90.1) | 331 (96.2) | |
| Others | 22 (5.1) | 9 (9.9) | 13 (3.8) | |
| Bedroom ambient light level, n (%) | 0.603 b | |||
| Darkest level | 198 (45.5) | 40 (44.0) | 158 (45.9) | |
| Middle level | 199 (45.8) | 45 (49.5) | 154 (44.8) | |
| Lightest level | 38 (8.7) | 6 (6.6) | 32 (9.3) | |
| Physical activity (MET-h/week), median (IQR) | 103.8 (82.9–126.9) | 103.8 (84.5–131.7) | 103.8 (78.9–125.8) | 0.421c |
| DASH score, mean ± SD | 22.9 ± 2.1 | 22.5 ± 2.1 | 23.0 ± 2.1 | 0.044 a |
| Sedentary behavior (h), median (IQR) | 4.0 (2.4–5.5) | 3.0 (1.6–4.6) | 4.3 (2.6–5.5) | <0.001 c |
| Sleep duration (h), mean ± SD | 6.8 ± 1.2 | 7.2 ± 1.2 | 6.7 ± 1.2 | <0.001 a |
| Insomnia, n (%) | 154 (35.4) | 33 (36.3) | 121 (35.2) | 0.847 b |
| BMI (kg/m2), mean ± SD | 23.8 ± 3.2 | 23.8 ± 3.1 | 23.8 ± 3.2 | 0.919a |
| WC (cm), mean ± SD | 83.2 ± 11.0 | 83.7 ± 11.4 | 83.0 ± 11.0 | 0.571 a |
| HC (cm), mean ± SD | 98.8 ± 7.5 | 98.3 ± 7.7 | 99.1 ± 7.5 | 0.413 a |
| WHR, mean ± SD | 0.84 ± 0.07 | 0.85 ± 0.07 | 0.84 ± 0.07 | 0.111 a |
| WHtR, mean ± SD | 0.50 ± 0.06 | 0.50 ± 0.06 | 0.51 ± 0.06 | 0.069 a |
| BF%, mean ± SD | 29.1 ± 7.9 | 27.4 ± 7.5 | 29.6 ± 7.9 | 0.022 a |
| FMI (kg/m2), mean ± SD | 7.3 ± 2.7 | 6.8 ± 2.4 | 7.7 ± 2.8 | 0.039 a |
| Menopausal status, n (%) | 0.746 b | |||
| Premenopausal | 413 (94.9) | 87 (95.6) | 326 (94.8) | |
| Postmenopausal | 22 (5.1) | 4 (4.4) | 18 (5.2) | |
| Current use of oral contraceptives, n (%) | 0.225 b | |||
| No | 409 (94.0) | 88 (96.7) | 321 (93.3) | |
| Yes | 26 (6.0) | 3 (3.3) | 23 (6.7) |
Values are expressed as the mean ± standard deviation (SD) or median (interquartile range (IQR)) or number (%); a p-values were from Student’s t-test; b p-values were from Pearson’s chi-square test; c p-values were from Wilcoxon Scores (Rank Sums). * The age ranges for the total participants, day workers, and night shift workers were 26–57, 31–52, and 26–57, respectively. BMI, body mass index; DASH, dietary approaches to stop hypertension; WC, waist circumference; HC, hip circumference; WHtR, waist-to-height ratio; WHR, waist-to-height ratio; BF%, body fat percentage; FMI, fat mass index.