title: Nightshift work job exposure matrices and urinary 6-sulfatoxymelatonin levels among healthy Chinese         women.
abstract: OBJECTIVE
  Six-sulfatoxymelatonin (aMT6s) is a primary urinary metabolite of melatonin. We examined the         association between aMT6s levels and shift work estimated by a job exposure matrix (JEM) among healthy participants of         the Shanghai Women's Health Study.
  
  
  METHODS
  Creatinine-adjusted aMT6s levels were measured in the urine samples         of 300 women and related to JEM shift work categories.
  
  
  RESULTS
  Adjusted geometric means of aMT6s levels from urine         samples collected before 08:00 hours were lower among persons holding nighttime shift work jobs. The adjusted aMT6s         levels (ng/mg creatinine) were 8.36 [95% confidence intervals (95% CI) 4.47-15.6], 6.37 (95% CI 3.53-11.5),         6.20 (95% CI 3.33-11.5), 3.81 (95% CI 2.02-7.19), and 3.70 (95% CI 1.92-7.11) from the lowest (never         held a shift work job) to the highest (current job likely involved all-night shift work) shift work JEM scores         (P=0.05).
  
  
  CONCLUSIONS
  Our results indicate that nightshift work JEM scores were significantly and inversely associated         with aMT6s levels in early morning spot urine samples collected between 07:00-08:00 hours.
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA. jib@mail.nih.gov
authors.forename: Bu-Tian
authors.initials: BT
authors.lastname: Ji
authors.forename: Yu-Tang
authors.initials: YT
authors.lastname: Gao
authors.forename: Xiao-Ou
authors.initials: XO
authors.lastname: Shu
authors.forename: Gong
authors.initials: G
authors.lastname: Yang
authors.forename: Kai
authors.initials: K
authors.lastname: Yu
authors.forename: Shou-Zheng
authors.initials: SZ
authors.lastname: Xue
authors.forename: Hong-Lan
authors.initials: HL
authors.lastname: Li
authors.forename: Linda M
authors.initials: LM
authors.lastname: Liao
authors.forename: Aaron
authors.initials: A
authors.lastname: Blair
authors.forename: Nathaniel
authors.initials: N
authors.lastname: Rothman
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
authors.forename: Wong-Ho
authors.initials: WH
authors.lastname: Chow
mesh_terms: D000328:Adult; D000368:Aged; D002681:China; D005260:Female; D006801:Humans; D008550:Melatonin / Q000031:analogs & derivatives* / Q000652:urine; D008875:Middle Aged; D012016:Reference Values; D014940:Work Schedule Tolerance
chemical_list: C054513:6-sulfatoxymelatonin; D008550:Melatonin