Impacts of shift work induced chronic circadian disruption and gender on plasma inflammatory cytokine levels

Abstract

Shift work can lead to disruption of the circadian rhythm which results in an irregular sleep pattern and subsequent alteration of plasma cytokine levels. And little is known about gender differences in plasma cytokine levels. The aims of this study were to investigate the impacts of shift work induced chronic circadian disruption and gender on plasma inflammatory cytokine levels. Fifty-one healthy adults were recruited and divided into three age-matched groups according to gender and shift work status

Group A- day time working men (39.7 ± 3.3 years), Group B- night shift working men (39.1 ± 4.5 years), and Group C- day time working women (35.3 ± 11.5 years). The Pittsburgh Sleep Quality Index (PSQI) was assessed of each subject and plasma concentrations of IL-1β, IL-6, IL-10, and TNF-α were measured. Group B subjects reported higher PSQI scores than Group A and C subjects and PSQI score was significantly associated with shift work status (β=0.372, p<0.05). There were significant differences in plasma IL-1β, IL-6, IL-10, and TNF- α levels among the three groups with Group B showing the highest, and Group C showing the lowest values. Plasma IL-6 level was significantly associated with PSQI score (β=0.317, p<0.05) and plasma levels of IL-1β (β=0.436, p<0.05), IL-10 (β=0.572, p<0.05), and TNF-α (β=0.630, p<0.05) were significantly associated with gender. These results suggest that shift work induced chronic circadian disruption can worsen sleep quality and poor sleep quality increases plasma IL-6 level. Men have higher plasma IL-1β, IL-10, and TNF-α levels compared to women.