title: Insufficient Sleep and Risk of Prostate Cancer in a Large Swedish Cohort.
abstract: OBJECTIVE
  There are some data to suggest that insufficient sleep, including short sleep duration and sleep disruption, may be associated with an increased risk of cancer. We investigated the association between sleep duration and sleep disruption and risk of prostate cancer.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Sweden.
  
  
  METHODS
  A total of 14,041 men in the Swedish National March Cohort.
  
  
  METHODS
  None.
  
  
  RESULTS
  Habitual sleep duration and sleep disruption were self-reported in 1997. Prostate cancer diagnoses, including lethal (metastases at diagnosis or death from prostate cancer) and advanced (stage T4, N1, or M1 at diagnosis or death from prostate cancer), were determined from linkage to nationwide cancer registries through 2010. We conducted Cox proportional hazards regression adjusted for potential confounding variables. During 13 years of follow-up, we identified 785 cases of incident prostate cancer, including 118 lethal and 127 advanced cases. Four percent of men reported sleeping 5 h or less a night, and 2% reported sleeping 9 h or more per night. We found no association between sleep duration and risk of prostate cancer overall or for advanced/lethal disease. We also did not find an association between prostate cancer and sleep disruption, as defined by difficulty falling asleep, difficulty maintaining sleep, sleep quality, and restorative power of sleep.
  
  
  CONCLUSIONS
  In this large prospective study from Sweden, we found no association between habitual sleep duration or sleep disruption and risk of prostate cancer.
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, Boston, MA.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Markt
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Grotta
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Olof
authors.initials: O
authors.lastname: Nyren
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, Boston, MA.|Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Hans-Olov
authors.initials: HO
authors.lastname: Adami
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, Boston, MA.|Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA.
authors.forename: Lorelei A
authors.initials: LA
authors.lastname: Mucci
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, Boston, MA.|Centre of Public Health Sciences, University of Iceland, Reykjavik, Iceland.
authors.forename: Unnur A
authors.initials: UA
authors.lastname: Valdimarsdottir
authors.affiliation: Surgery and Perioperative Sciences, Urology and Andrology, Umeå University Hospital, Umeå, Sweden.
authors.forename: Pär
authors.initials: P
authors.lastname: Stattin
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.|Department of Statistics and Quantitative Methods, Unit of Biostatistics and Epidemiology, University of Milano-Bicocca, Milan, Italy.
authors.forename: Rino
authors.initials: R
authors.lastname: Bellocco
authors.affiliation: Unit of Clinical Epidemiology, Department of Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Ylva Trolle
authors.initials: YT
authors.lastname: Lagerros
mesh_terms: D015331:Cohort Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D012306:Risk; D057566:Self Report; D012890:Sleep / Q000502:physiology; D012892:Sleep Deprivation / Q000150:complications / Q000453:epidemiology*; D007319:Sleep Initiation and Maintenance Disorders / Q000150:complications / Q000453:epidemiology*; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors
keywords: prostate cancer; sleep disruption; sleep duration