title: Association between lunar phase and sleep characteristics.
abstract: OBJECTIVE
  Popular belief holds that the lunar cycle affects human physiology, behavior, and health, including sleep. To date, only a few and conflicting analyses have been published about the association between lunar phases and sleep. Our aim was to analyze the relationship between lunar phases and sleep characteristics.
  
  
  METHODS
  In this retrospective, cross-sectional analysis, data from 319 patients who had been referred for sleep study were included. Individuals with apnea-hypopnea index ≥ 15/h were excluded. Socio-demographic parameters were recorded. All participants underwent one-night standard polysomnography. Associations between lunar cycle (new moon, full moon and alternate moon) and sleep parameters were examined in unadjusted and adjusted models.
  
  
  RESULTS
  Fifty-seven percent of patients were males. Mean age for men was 45 ± 14 years and 51 ± 12 years for women. In total, 224 persons had their sleep study done during alternate moon, 47 during full moon, and 48 during new moon. Full moon was associated with lower sleep efficiency [median (%) (IQR): new moon 82 (18), full moon 74 (19), alternate moon 82 (15); P < 0.001], less deep sleep [median (%) (IQR): new moon 9 (9), full moon 6 (4), alternate moon 11 (9); P < 0.001], and increased REM latency [median (min) (IQR): new moon 98 (74), full moon 137 (152), alternate moon 97 (76); P < 0.001], even after adjustment for several covariables.
  
  
  CONCLUSIONS
  The results are consistent with a recent report and the widely held belief that sleep characteristics may be associated with the full moon.
authors.affiliation: Institute of Behavioral Sciences, Semmelweis University, Budapest, Hungary.
authors.forename: Csilla Zita
authors.initials: CZ
authors.lastname: Turányi
authors.affiliation: Institute of Behavioral Sciences, Semmelweis University, Budapest, Hungary.
authors.forename: Katalin Zsuzsanna
authors.initials: KZ
authors.lastname: Rónai
authors.affiliation: Institute of Behavioral Sciences, Semmelweis University, Budapest, Hungary; 1st Department of Internal Medicine, Semmelweis University, Budapest, Hungary.
authors.forename: Rezső
authors.initials: R
authors.lastname: Zoller
authors.affiliation: Institute of Behavioral Sciences, Semmelweis University, Budapest, Hungary.
authors.forename: Orsolya
authors.initials: O
authors.lastname: Véber
authors.affiliation: Institute of Behavioral Sciences, Semmelweis University, Budapest, Hungary; Institute of Epidemiology and Social Medicine, University of Muenster, Muenster, Germany.
authors.forename: Mária Eszter
authors.initials: ME
authors.lastname: Czira
authors.affiliation: Institute of Behavioral Sciences, Semmelweis University, Budapest, Hungary.
authors.forename: Ákos
authors.initials: Á
authors.lastname: Újszászi
authors.affiliation: Institute of Behavioral Sciences, Semmelweis University, Budapest, Hungary.
authors.forename: Gergely
authors.initials: G
authors.lastname: László
authors.affiliation: Institute of Behavioral Sciences, Semmelweis University, Budapest, Hungary; Institute of Epidemiology and Social Medicine, University of Muenster, Muenster, Germany.
authors.forename: András
authors.initials: A
authors.lastname: Szentkirályi
authors.affiliation: Institute of Behavioral Sciences, Semmelweis University, Budapest, Hungary; 1st Department of Internal Medicine, Semmelweis University, Budapest, Hungary.
authors.forename: Andrea
authors.initials: A
authors.lastname: Dunai
authors.affiliation: Institute of Behavioral Sciences, Semmelweis University, Budapest, Hungary.
authors.forename: Anett
authors.initials: A
authors.lastname: Lindner
authors.affiliation: Institute of Behavioral Sciences, Semmelweis University, Budapest, Hungary.
authors.forename: Julianna Luca
authors.initials: JL
authors.lastname: Szőcs
authors.affiliation: Institute of Behavioral Sciences, Semmelweis University, Budapest, Hungary.
authors.forename: Ádám
authors.initials: Á
authors.lastname: Becze
authors.affiliation: Institute of Behavioral Sciences, Semmelweis University, Budapest, Hungary.
authors.forename: Andrea
authors.initials: A
authors.lastname: Kelemen
authors.affiliation: Institute of Behavioral Sciences, Semmelweis University, Budapest, Hungary.
authors.forename: Zsófia
authors.initials: Z
authors.lastname: Lendvai
authors.affiliation: Division of Nephrology, Department of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA.
authors.forename: Miklos Z
authors.initials: MZ
authors.lastname: Molnar
authors.affiliation: Institute of Behavioral Sciences, Semmelweis University, Budapest, Hungary; Institute of Pathophysiology, Semmelweis University, Budapest, Hungary. Electronic address: istvan@nefros.net.
authors.forename: István
authors.initials: I
authors.lastname: Mucsi
authors.affiliation: Institute of Behavioral Sciences, Semmelweis University, Budapest, Hungary; Department of Psychiatry, University Health Network, University of Toronto, Toronto, Canada.
authors.forename: Márta
authors.initials: M
authors.lastname: Novák
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016081:Moon; D017286:Polysomnography; D012189:Retrospective Studies; D012890:Sleep / Q000502:physiology; D007319:Sleep Initiation and Maintenance Disorders / Q000209:etiology / Q000503:physiopathology; D012895:Sleep, REM / Q000502:physiology
keywords: Full moon; Insomnia; Lunar cycle; Polysomnography; Sleep parameters