title: Urinary melatonin levels, sleep disruption, and risk of prostate cancer in elderly men.
abstract: Melatonin has anticarcinogenic properties in experimental models. We undertook a case-cohort study of 928 Icelandic men without prostate cancer (PCa) nested within the Age, Gene/Environment Susceptibility (AGES)-Reykjavik cohort to investigate the prospective association between first morning-void urinary 6-sulfatoxymelatonin (aMT6s) levels and the subsequent risk for PCa, under the hypothesis that men with lower aMT6s levels have an increased risk for advanced PCa. We used weighted Cox proportional hazards models to assess the association between first morning-void aMT6s levels and PCa risk, adjusting for potential confounders. A total of 111 men were diagnosed with incident PCa, including 24 with advanced disease. Men who reported sleep problems at baseline had lower morning aMT6s levels compared with those who reported no sleep problems. Men with morning aMT6s levels below the median had a fourfold statistically significant increased risk for advanced disease compared with men with levels above the median (hazard ratio: 4.04; 95% confidence interval, 1.26-12.98). These results require replication in larger prospective studies with longer follow-up.
  
  
  RESULTS
  In this report, we evaluated the prospective association between urinary aMT6s levels and risk of PCa in an Icelandic population. We found that lower levels of aMT6s were associated with an increased risk for advanced PCa.
authors.affiliation: Centre of Public Health Sciences, University of Iceland, Reykjavik, Iceland; Faculty of Medicine, University of Iceland, Reykjavik, Iceland; The Icelandic Cancer Society, Reykjavik, Iceland.
authors.forename: Lara G
authors.initials: LG
authors.lastname: Sigurdardottir
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA. Electronic address: sec110@mail.harvard.edu.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Markt
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Rider
authors.affiliation: Department of Biostatistics, Harvard School of Public Health, Boston, MA, USA.
authors.forename: Sebastien
authors.initials: S
authors.lastname: Haneuse
authors.affiliation: Centre of Public Health Sciences, University of Iceland, Reykjavik, Iceland; Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA; Clinical Epidemiology Unit, Örebro University and Örebro University Hospital, Örebro, Sweden.
authors.forename: Katja
authors.initials: K
authors.lastname: Fall
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Eva S
authors.initials: ES
authors.lastname: Schernhammer
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Rulla M
authors.initials: RM
authors.lastname: Tamimi
authors.affiliation: Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA; Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Erin
authors.initials: E
authors.lastname: Flynn-Evans
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Julie L
authors.initials: JL
authors.lastname: Batista
authors.affiliation: Laboratory of Epidemiology and Population Sciences, National Institute on Aging, Bethesda, MD, USA.
authors.forename: Lenore
authors.initials: L
authors.lastname: Launer
authors.affiliation: Laboratory of Epidemiology and Population Sciences, National Institute on Aging, Bethesda, MD, USA.
authors.forename: Tamara
authors.initials: T
authors.lastname: Harris
authors.affiliation: Centre of Public Health Sciences, University of Iceland, Reykjavik, Iceland; Icelandic Heart Association, Kopavogur, Iceland.
authors.forename: Thor
authors.initials: T
authors.lastname: Aspelund
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Meir J
authors.initials: MJ
authors.lastname: Stampfer
authors.affiliation: Faculty of Medicine, University of Iceland, Reykjavik, Iceland; Icelandic Heart Association, Kopavogur, Iceland.
authors.forename: Vilmundur
authors.initials: V
authors.lastname: Gudnason
authors.affiliation: Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA; Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Charles A
authors.initials: CA
authors.lastname: Czeisler
authors.affiliation: Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA; Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Steven W
authors.initials: SW
authors.lastname: Lockley
authors.affiliation: Centre of Public Health Sciences, University of Iceland, Reykjavik, Iceland; Faculty of Medicine, University of Iceland, Reykjavik, Iceland; Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA.
authors.forename: Unnur A
authors.initials: UA
authors.lastname: Valdimarsdottir
authors.affiliation: Centre of Public Health Sciences, University of Iceland, Reykjavik, Iceland; Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Lorelei A
authors.initials: LA
authors.lastname: Mucci
mesh_terms: D000367:Age Factors; D015415:Biomarkers / Q000652:urine; D015536:Down-Regulation; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D015994:Incidence; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives* / Q000652:urine; D016016:Proportional Hazards Models; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000453:epidemiology*; D018570:Risk Assessment; D012307:Risk Factors; D012890:Sleep; D012893:Sleep Wake Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D013997:Time Factors
chemical_list: D015415:Biomarkers; C054513:6-sulfatoxymelatonin; D008550:Melatonin
keywords: Circadian rhythm; Melatonin levels; Prostate cancer
references.citation: Oncol Rep. 2000 Mar-Apr;7(2):347-51
references.pmid: 10671684
references.citation: Epidemiology. 1998 Sep;9(5):490-4
references.pmid: 9730026
references.citation: Cancer Epidemiol Biomarkers Prev. 2013 May;22(5):872-9
references.pmid: 23652374
references.citation: Cancer Epidemiol Biomarkers Prev. 2012 Jul;21(7):1002-11
references.pmid: 22564869
references.citation: J Natl Cancer Inst. 2013 Sep 4;105(17):1292-7
references.pmid: 23943864
references.citation: Clin Chim Acta. 1992 Aug 31;209(3):153-67
references.pmid: 1395046
references.citation: J Pineal Res. 2003 Oct;35(3):177-82
references.pmid: 12932201
references.citation: Endocrine. 2005 Jul;27(2):179-88
references.pmid: 16217131
references.citation: Horm Metab Res. 1987 Sep;19(9):437-40
references.pmid: 3692439
references.citation: Lancet Oncol. 2007 Dec;8(12):1065-6
references.pmid: 19271347