Table 1 Working hours per week, sleep patterns, score sleepiness, chronotype and social jetlag of employees according to shift worked.

From: Night workers have lower levels of antioxidant defenses and higher levels of oxidative stress damage when compared to day workers

  Night (n = 37) Day (N = 42) p-value
Working Hours/week 57.0 [42.0–69.0] 36.0 [36.0–40.0] <0.001*
Working time (years) 5.00 [2.00–12.5] 4.00 [2.00–10.75] 0.348
Sleepiness Score ( Epworth ) 10.76 ± 4.88 7.48 ± 4.00 0.002*
Daytime Sleepiness 16 (43.2) 9 (21.4) 0.037*
No sleepiness 21 (56.8) 33 (78.6)  
Mean Sleep Duration (h)
Work days 3:50 [2:22–4:27] 6:35 [5:28–7:35] <0.001*
Rest days 7:56 ± 1:58 8:33 ± 1:52 0.170
Chronotype (MSF E sc) (h) 3:44 ± 1:00 3:38 ± 1:25 0.708
Morning 21 (56.8) 29 (69.0) 0.260
Indifferent 12 (32.4) 7 (16.7)  
Evening 4 (10.8) 6 (14.3)  
Social Jetlag (h) 5:07 [2:35–7:53] 1:15 [0:45–2:02] <0.001*
Yes 32 (86.5) 25 (59.5) 0.011*
No 5 (13.5) 17 (40.5)  
  1. Values are presented as mean ± SD for normally distributed data or median (interquartile range) for non-normally distributed data. Comparisons between groups were done using the Student’s t-test or the Mann-Whitney test, for independent samples, for data with and without normal distribution, respectively, or by the Chi-square test, for variables expressed as frequency. *p < 0.05 indicates statistically significant difference. SJL was calculated based on the absolute difference between the average sleep time on working and rest days and was dichotomically categorized as >60 min (with SJL) or <60 min (without SJL).