TABLE 1.
Baseline Characteristics of study participants by weekly working hours
| Characteristics | Overall | Weekly working hours | P value for trend | ||
|---|---|---|---|---|---|
| 35‐40 | 41‐52 | >52 | |||
| Number | 97 856 | 18 315 | 52 952 | 26 589 | |
| Men (%) | 75.3 | 54.4 | 77.4 | 85.6 | <.001 |
| Current smoker (%) | 25.3 | 19.4 | 24.5 | 31.1 | <.001 |
| Alcohol intake (%)a | 45.9 | 39.2 | 45.8 | 50.8 | <.001 |
| Regular exercise (%)b | 12.2 | 13.5 | 12.5 | 10.7 | <.001 |
| High education level (%)c | 88.5 | 81.0 | 89.3 | 92.2 | <.001 |
| History of dyslipidemia (%) | 12.0 | 10.6 | 12.0 | 12.9 | <.001 |
| Medication for dyslipidemia (%) | 1.30 | 1.36 | 1.23 | 1.39 | .57 |
| Obesity (%)d | 31.0 | 26.4 | 30.7 | 34.5 | <.001 |
| High occupational stress (%)e | 16.6 | 11.8 | 15.0 | 22.8 | <.001 |
| Daytime work (%)f | 91.3 | 89.9 | 91.3 | 92.1 | <.001 |
| Age (years)* | 36.4 (6.5) | 37.7 (7.2) | 36.0 (6.4) | 36.2 (6.1) | <.001 |
| BMI (kg/m2)* | 23.6 (3.2) | 23.1 (3.2) | 23.6 (3.2) | 24.0 (3.2) | <.001 |
| Systolic BP (mm Hg)* | 108.8 (11.7) | 106.6 (12.2) | 109.0 (11.6) | 109.9 (11.2) | <.001 |
| Diastolic BP (mm Hg)* | 70.3 (9.4) | 69.1 (9.8) | 70.4 (9.3) | 71.1 (9.1) | <.001 |
| Glucose (mg/dL)# | 93 (88‐98) | 92 (87‐98) | 93 (88‐98) | 93 (88‐98) | <.001 |
| HOMA‐IR# | 1.27 (0.85‐1.87) | 1.23 (0.82‐1.81) | 1.27 (0.85‐1.87) | 1.30 (0.86‐1.91) | <.001 |
| Total cholesterol (mg/dL)* | 194.9 (33.6) | 193.0 (33.9) | 194.8 (33.6) | 196.4 (33.2) | <.001 |
| LDL‐C (mg/dL)* | 122.7 (31.5) | 119.7 (31.7) | 122.7 (31.6) | 124.7 (31.2) | <.001 |
| HDL‐C (mg/dL)* | 56.7 (14.6) | 59.1 (15.3) | 56.6 (14.6) | 55.2 (14.0) | <.001 |
| Triglycerides (mg/dL)# | 96 (68‐142) | 88 (62‐133) | 96 (68‐142) | 100 (71‐148) | <.001 |
| BUN (mg/dL)* | 12.4 (2.9) | 12.2 (3.0) | 12.4 (2.9) | 12.6 (2.9) | <.001 |
| Creatinine (mg/dL)* | 0.91 (0.17) | 0.84 (0.18) | 0.91 (0.16) | 0.94 (0.15) | <.001 |
| Uric acid (mg/dL)* | 5.71 (1.41) | 5.25 (1.45) | 5.76 (1.39) | 5.94 (1.35) | <.001 |
| hsCRP (mg/L)# | 0.04 (0.03‐0.09) | 0.04 (0.02‐0.08) | 0.04 (0.03‐0.09) | 0.05 (0.03‐0.09) | .01 |
Data are expressed as *mean (standard deviation), #median (interquartile range), or percentage.
Abbreviations: BMI, body mass index; BP, blood pressure; HOMA‐IR, homeostasis model assessment of insulin resistance; LDL‐C, low‐density lipoprotein cholesterol; HDL‐C, high‐density lipoprotein cholesterol; BUN, blood urea nitrogen; hsCRP, high‐sensitivity C‐reactive protein.
a
≥10 g/day.
b
≥3 times per week.
c
≥College graduate.
d
BMI ≥25 kg/m2.
e
Median cutoff values of total KOSS‐SF score: 50.1.
f
Participants who answered "I work mostly during the day (between 6 AM and 6 PM)".