Work and sleep physiology

Abstract

Sleep is a circadian process coordinated by a pacemaker rhythm generated in the hypothalamus. It is influenced by both exogenous and endogenous factors such as body temperature, lightdark cycle and other factors connected to individual variability (morning/serotine chronotype, long/short sleeper). Sleep is structured in distinct phases defined REM and NON-REM which differ according to the synchronization of the EEG and for the variability of some body functions. Numerous studies have proved that insomnia is the most common sleep disorder worldwide. Sleep disorders have destructive consequences on individual health and can affect the quality of work in terms of injuries, accidents, absenteeism and performance. On the other hand, some working conditions (shift work, work-related stress) may themselves cause sleep impairment leading to the same negative consequences. Among the sleep disorders that are of interest in Occupational Medicine, a leading role is given to syndromes characterized by Excessive Daytime Sleepiness including restless legs syndrome, periodic limb movements and obstructive sleep apnea (OSAS). OSAS is characterized by repeated episodes of upper airway obstruction with sleep apnea followed by a restarting ventilation that cause reduction of sleep or awakening. Occupational Medicine wants to face the problem in terms of prevention and intervention.