Table 1. Characteristics of the study population (N=511).
SJL: social jetlag; WD: workday; FD: free day; BMI: body mass index; HbA1c: glycated hemoglobin; DM: diabetes mellitus; SD: standard deviation
| Variable | Level | Value | % |
| Gender | Male | 258 | 51.0 |
| Group | Controlled DM | 215 | 49.7 |
| SJL status | SJL | 292 | 58.4 |
| Sleeping hours on workdays | Mean | 6.8 | - |
| Sleeping hours on free days | Mean | 7.85 | - |
| Regular work | Yes | 311 | 61.1 |
| Worked days | ≤5 days | 406 | 92.3 |
| Alarm clock (WD) | Yes | 296 | 57.9 |
| I wake up before the alarm (WD) | Yes | 121 | 39.2 |
| Alarm clock (FD) | Yes | 129 | 25.7 |
| I freely choose my sleep time (FD) | Yes | 152 | 31.0 |
| I had shift work in the last 3 months | Yes | 24 | 8.2 |
| Flexibility of my work | Very flexible | 91 | 34.0 |
| Little flexible | 103 | 38.4 | |
| Rather flexible | 58 | 21.6 | |
| Not very flexible | 16 | 6.0 | |
| I travel to work in | Vehicles | 256 | 84.2 |
| Foot/bike, etc. | 16 | 5.3 | |
| I work from home | 32 | 10.5 | |
| Smoking | Yes | 38 | 15.8 |
| Coffee | <4 cups | 305 | 62.1 |
| Tea | Yes | 403 | 84.0 |
| Caffeinated drinks | Yes | 143 | 38.5 |
| Sleep medications | Yes | 13 | 4.0 |
| Age, years | Mean | 47.64 | - |
| SD | 12.23 | - | |
| Height, cm | Mean | 163.61 | - |
| SD | 9.77 | - | |
| Weight, kg | Mean | 84.20 | - |
| SD | 20.33 | - | |
| BMI, kg/m2 | Mean | 31.42 | - |
| SD | 6.90 | - | |
| HbA1c, % | Mean | 7.98 | - |
| SD | 1.90 | - | |
| Working time hours | Mean | 6.64 | - |
| SD | 2.19 | - |