title: Increased plasma homocysteine levels in shift working bus drivers.
abstract: BACKGROUND
  Previous studies have indicated an association between shift work and cardiovascular disease. There is also considerable epidemiological evidence that hyperhomocysteinemia is an independent risk factor for cardiovascular disorders.
  
  
  OBJECTIVE
  To analyse plasma homocysteine levels in shift work bus drivers, and to investigate possible relations with sleep parameters and other biochemical factors.
  
  
  METHODS
  Blood samples were collected from 30 male shift working long-haul bus drivers in a Brazilian sample and analysed for plasma levels of homocysteine, folic acid, vitamin B(12), and serum lipids. A group of 22 daytime workers, matched for age and body mass index served as controls. The incidence of mutations in the gene coding for methylene tetrahydrofolate, an enzyme which is related to hyperhomocysteinemia, was also assessed. Polysomnographic recordings were obtained from the target group.
  
  
  RESULTS
  Bus drivers showed significantly higher levels of plasma homocysteine than the control group (18.57 v 9.43 micro M). Most of the other biochemical, behavioural, and molecular parameters did not differ between groups. Likewise, sleep parameters appeared to be within the normal range.
  
  
  CONCLUSIONS
  The significantly increased plasma homocysteine levels in long-haul bus drivers did not appear to be secondary to other biochemical or behavioural problems in this group. These results suggest that hyperhomocysteinemia may be involved in the increased incidence of cardiovascular diseases observed in shift workers.
authors.affiliation: Department of Psychobiology, Universidade Federal de São Paulo-Escola Paulista de Medicina, Rua Napoleão de Barros 925, São Paulo, Brazil 42024-002.
authors.forename: P J F
authors.initials: PJ
authors.lastname: Martins
authors.forename: V
authors.initials: V
authors.lastname: D'Almeida
authors.forename: N
authors.initials: N
authors.lastname: Vergani
authors.forename: A B A
authors.initials: AB
authors.lastname: Perez
authors.forename: S
authors.initials: S
authors.lastname: Tufik
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000209:etiology*; D023281:Genomics / Q000379:methods; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood / Q000209:etiology; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000209:etiology*; D012307:Risk Factors; D020178:Sleep Disorders, Circadian Rhythm / Q000150:complications; D014186:Transportation
chemical_list: D015415:Biomarkers; D006710:Homocysteine