Abstract. Shiftwork-induced sleep deprivation and circadian disruption probably leads to an increase in the production of cytokines
and dysregulation of innate immune system, respectively. This project aims evaluating changes in salivary IL-1 beta,
cortisol, and melatonin in night workers. Method. Two day and three night healthy workers participated in this study. Sleep
was evaluated by actimetry and activity protocols. Saliva was collected at waking and bedtime the last workday and the following
two days-off and was analyzed by ELISA. Results. Neither sleep duration nor efficiency showed any association with
salivary IL-1beta. IL-1beta levels were higher at waking than at bedtime during working days for all workers, but only one day
and one night-worker maintained this pattern and hormone rhythms during days off. For this night worker, melatonin levels
were shifted to daytime. A second one presented clear alterations in IL-1beta and hormone rhythms on days-off. Conclusions.
Our preliminary results suggest that night work can disturb the variation pattern of salivary IL-1beta. No association of this
variation with sleep was observed. It seems that disruption in hormone rhythms interfere with salivary IL-1beta production. IL-
1beta production pattern seems to be maintained when rhythms are present, in spite of a shift in melatonin secretion.