A-040 Night Shift Work Could Induce Oxidatively Generated Damage to DNA: A Pilot Study

Abstract Background Currently, specific effects of different night shift modes on human oxidative stress still need to be explored in a realistic cohort study. We aimed to evaluate the effect of night shift on human nucleic acid damage status. Methods We recruited 16 healthy volunteers (aged, 33 ± 5 years) working the night shifts at the Department of Laboratory Medicine at Peking Union Medical College Hospital. Their matched serum and urine samples were collected at four time points: before, during (twice), and after the night shift period. The levels of 8-oxo-7,8-dihydroguanosine (8-oxoG) and 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG), two important nucleic acid damage markers, were accurately determined based on a robust self-established LC-MS/MS method. The Mann–Whitney U or Kruskal-Wallis test was used for comparisons. Results The levels of serum 8-oxodG, estimated glomerular filtration rate corrected serum 8-oxodG, and 8-oxodG in serum to urine ratio significantly increased during the night shift period. These levels were significantly higher than at baseline even after 1 month of discontinuing; but no such significant change was found for 8-oxoG. Moreover, 8-oxoG and 8-oxodG levels revealed a significantly positive association with many routine biomarkers such as total bilirubin and urea levels, and significantly negative association with serum lipids such as total cholesterol levels. Conclusion The results of our cohort study suggested that working the night shifts may increase the oxidatively generated damage to DNA even after a month of discontinuing night shift work. Further studies with large-scale cohorts, different night shift modes, and longer follow-up times are needed to clarify the short- and long-term effect of night shifts on DNA damage, and find effective solutions to combat the negative effects.