title: Association of working hours with biological indices related to the cardiovascular system among engineers in a machinery manufacturing company.
abstract: A field survey of 278 engineers (20-59 years) in a machinery manufacturing company was conducted to investigate the association of working hours with biological indices related to the cardiovascular system (heart rate variability, blood pressure and serum levels of magnesium, dehydroepiandrosterone sulfate <DHEA-S> and cholesterol). Average working hours (defined as <"hours at workplace" + "half a commuting time">) and sleeping hours in this study were 60.2 +/- 6.3 hr/week and 6.6 +/- 0.8 hr/day respectively. There were no significant relationships between working hours and biological indices related to the cardiovascular system, but sleeping hours was closely related to working hours negatively. Furthermore, the serum DHEA-S level was significantly related to sleeping hours positively. Combining these two results, it appeared that long working hours might lower the serum DHEA-S level due to the reduction of sleeping hours.
authors.affiliation: Division of Work Stress Control, National Institute of Industrial Health, Kawasaki, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Sasaki
authors.forename: K
authors.initials: K
authors.lastname: Iwasaki
authors.forename: T
authors.initials: T
authors.lastname: Oka
authors.forename: N
authors.initials: N
authors.lastname: Hisanaga
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D002320:Cardiovascular Physiological Phenomena; D002784:Cholesterol / Q000097:blood; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood; D005221:Fatigue; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008274:Magnesium / Q000097:blood; D008297:Male; D008875:Middle Aged; D016272:Occupational Health; D010561:Personnel Staffing and Scheduling; D012890:Sleep; D016526:Workload
chemical_list: D019314:Dehydroepiandrosterone Sulfate; D002784:Cholesterol; D008274:Magnesium