Gender Differences in the Subjective and Objective Markers for Fatigue Associated with Shift Work: A Pilot Study

Purpose: This study investigated if there were differences between men and women, in the indices of fatigue, as a result of shift work. Participants and methods: The participants were 24 nurses (12 men and 12 women), who were performing shift work at a hospital; they were matched by age, working hours and workplace. A self-administered survey was distributed, which included a set of questionnaires on the subjective symptoms and visual analogue scale [VAS] scores for fatigue. In addition, physiological tests (acceleration of pulse waves) and blood tests (reactive oxygen metabolite [d-ROM]; and biological antioxidant potential [BAP] were conducted before and after each of the three different shifts. Results: The subjective symptoms improved after the day and evening shifts, but worsened after the night shifts. For the VAS, the scores decreased after all the shifts; for the night shifts, the changes in the scores in the men were significantly greater than those observed in the women (p=0.001). On comparing the before and after-shift values of the three different shifts, no significant differences were observed for the evening or night shifts, in terms of the acceleration of pulse waves, d-ROM, or BAP. For the acceleration of pulse waves for the day shift, the values were elevated after the shift for men, while it decreased for women. Similarly, the results before and after the work shifts, in terms of BAP, were 184.9 ± 281.9 μmol/L for men and -160.4 ± 307.5 μmol/L for women, showing an increase in the men and a decrease in the women, after the shifts. However, there was no significant gender difference, in terms of the d-ROM. Conclusion: Gender differences were observed in the objective fatigue indicators, in spite of the fact that the mean age of both the men and women was the same and their workplace was the same. It is necessary to conduct future studies to clear support issues for shift working by gender.