Influence of night shift work on functional state of autonomous nervous system in workers exposed to occupational hazards

Abstract

Features of work schedule in continuous technologic processes necessitate study of its influence on vegetative functions dynamics, to develop early diagnostic measures and prevention of health disorders. The examination covered 22 males exposed to occupational hazards at work schedule including night shifts; average age 35,3±4,1 years, average length of service 10,2±3,1 years. The reference group included 28 males with analogous occupations and work conditions with work schedule without night shifts; average age 37,9±3.3 years (p>0,05), average length of service 13,2±3,2 years (p>0,05). Clinical evaluation of the autonomous nervous system was performed according to standardized protocol and questionnaire of A.M. Vein. Variability of heart rhythm was assessed with software complex «Poly-Spectr–8/EX» by standard method. Findings are that the workers exposed to occupational hazards and engaged into work schedule with night shifts during 5 years demonstrate the level of vegetative regulation at rest corresponding to the physiologic one; but on exertion there is intense stress of adaptation mechanisms and significant decrease of functional resources. If length of service from 5 to 10 years, the vegetative regulation is characterized by dysbalance of adaptation mechanisms and vegetative dysfunction development; additional exertion cause overstrain sympathetic part with depletion of compensatory mechanisms. If length of service over 10 years, there is excessive involvement of sympathetic influences after orthoclinostatic test — that indicates severe strain of vegetative regulation mechanisms.