The effect of shift work on health is mainly thought to be related to its interference with circadian rhythms with consequence effects on sleep, hormonal balance, and features of metabolic syndrome.Background
The aim of this work was to investigate the impact of shift work on sleep problems, hormonal balance, and features of metabolic syndrome (BMI, cardiovascular problems, type II diabetes mellitus) among a sample of Egyptian industrial workers.Patients and methods
Participants were 99 male workers (36 morning shift workers, 19 afternoon shift workers, and 44 night shift workers), with an age ranging from 25 to 60 years with fixed shift for at least 2 years. Participants were assessed using Diagnostic and Statistical Manual of Mental Disorders, 4th ed., text revision Diagnostic Criteria for Circadian Rhythm Sleep Disorder (shift work type), and by using sleep characteristics, and sleep/sleepiness problems items from Karolinska Sleep Questionnaire. Features of metabolic syndrome were obtained (BMI used to assess obesity, history of cardiovascular problems, and type II diabetes mellitus). Blood samples were collected at workplace, and morning samples were examined to detect levels of 6-sulfatoxymelatonin, leptin, testosterone, prolactin, and thyroid-stimulating hormone.Results
Sleep problems were higher in night shift workers and they had higher BMI and higher prevalence of type II diabetes and cardiovascular problems than those workers in the morning and afternoon shifts, and the differences were statistically significant. The concentrations of 6-sulfatoxymelatonin, leptin, and testosterone were lower in those night shift workers than afternoon and morning shift workers. Prolactin and thyroid-stimulating hormone levels were higher in the night shift workers than in the other two groups, with a statistically significant differences (P<0.05). Night shift workers had disturbed hormone levels than morning and afternoon workers, and hormonal levels were independently influenced by night shift, but not by BMI, or sleep disorders, thus suggesting that the difference in hormonal levels may be will mediated by circadian disruption.Conclusion
Night shift workers are at risk for sleep problems, hormonal imbalance, and features of metabolic syndrome (high BMI, cardiovascular problems, type II diabetes mellitus).