Table 2 Main effects of work shift, social jetlag (SJL) and their interaction for parameters of oxidative damage and antioxidant defenses, adjusted for age and working hours.

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

  Night Day Shift SJL Shift*SJL
With SJL (n = 33) Without SJL (n = 4) With SJL (n = 25) Without SJL (n = 17) DF p-value DF p-value DF p-value
TBARS (µmol/mg protein) 0.62 [0.59–0.66] 0.56 [0.49–0.65] 0.58 [0.54–0.61] 0.61 [0.57–0.66] 1 0.896 1 0.468 1 0.064
Carbonyls (nmol/mg protein) 2.79 [2.66–2.93] 2.51 [2.23–2.81] 2.74 [2.60–2.88] 2.79 [2.62–2.98] 1 0.288 1 0.237 1 0.080
H202 (µM H202) 32.5 [26.2–40.4] 24.5 [14.9–40.3] 26.2 [20.9–32.9] 18.7 [14.2–24.7] 1 0.204 1 0.051 1 0.867
Nitrite (nmol/mg protein) 1.74 [1.53–1.97] 1.64 [1.21–2.21] 2.02 [1.77–2.30] 2.05 [1.75–2.41] 1 0.089 1 0.823 1 0.684
FRAP (mM Fe+2) 0.78 [0.73–0.83] 0.77 [0.64–0.91] 0.95 [0.89–1.02] 0.95 [0.88–1.03] 1 0.002* 1 0.961 1 0.994
CAT (nmol/mg protein) 11.1 [9.7–12.6] 11.6 [8.1–16.7] 15.2 [13.2–17.4] 14.1 [11.7–16.8] 1 0.034* 1 0.951 1 0.570
SOD (USOD/mg protein) 610 [587–633] 610 [556–669] 712 [684–742] 697 [660–736] 1 <0.001* 1 0.915 1 0.900
GPx (nmol/min/mL) 12.8 [10.3–16.2] 14.4 [8.32–25.1] 8.4 [6.6–10.8] 11.9 [8.90–16.1] 1 0.085 1 0.126 1 0.571
  1. 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).
  2. Abbreviations: TBARS, thiobarbituric acid reactive substances; carbonyls, plasma protein oxidation; H202, oxygen peroxide; FRAP, ferric reducing antioxidant power (total antioxidant capacity); CAT: catalase; SOD, superoxide dismutase; GPx, glutathione peroxidase.
  3. *p < 0.05 indicates statistically significant values. Data were represented as mean and Wald confidence interval (95% CI).