Sleep is a vital function regulated by a circadian rhythm. Its restriction results in daytime sleepiness, which disrupts social life and affects behaviours that have survival value, particularly for occupations requiring a high level of alertness, such as shift workers and drivers.Methods
Data from published reports and unpublished preliminary results will be used to illustrate the genetics of the sleep/wake cycle and the mechanisms underlying the health consequences of sleep loss.Result
Shift-work can alter the sleep/wake cycle and the circadian rhythm of biological functions, which results in daytime sleepiness and disruption of social life. About 10% shift workers complain daytime sleepiness or insomnia, impairment in their performance, and cardiovascular, digestive and neuropsychiatric symptoms. Polymorphisms in genes expressing the proteins that regulate the circadian functions result in different chronotypes with diverse capability of adapting to shift rotation schedules. Circadian genes also regulate the maintenance of energy balance; sleep loss is a contributor to the development of metabolic disorders, which min turn, are a major risk factor for obstructive sleep apnea syndrome (OSAS). Day time sleepiness is frequently consequent to OSAS, a major cause of deadly road accidents, and an occupational hazard for drivers of commercial and public transport vehicles and commuters to work, but also for the general public. Early detection of OSAS symptoms shall be part of health surveillance protocols of workers in commercial and public transport trades.Discussion
Several approaches are suggested to detect and monitor daytime sleepiness and OSAS among shift workers and long haul drivers, including specific questionnaires, and biomonitoring the salivary concentration of melatonin and cortisol level at a specific day time. A carefully designed biomonitoring protocol would help to reduce the health burden of sleep disorders and to save lives.