Bad sleep? Don't blame the moon! A population-based study.
BACKGROUND
The aim of this study was to evaluate if there is a significant effect of lunar phases on subjective and objective sleep variables in the general population.


METHODS
A total of 2125 individuals (51.2% women, age 58.8 ± 11.2 years) participating in a population-based cohort study underwent a complete polysomnography (PSG) at home. Subjective sleep quality was evaluated by a self-rating scale. Sleep electroencephalography (EEG) spectral analysis was performed in 759 participants without significant sleep disorders. Salivary cortisol levels were assessed at awakening, 30 min after awakening, at 11 am, and at 8 pm. Lunar phases were grouped into full moon (FM), waxing/waning moon (WM), and new moon (NM).


RESULTS
Overall, there was no significant difference between lunar phases with regard to subjective sleep quality. We found only a nonsignificant (p = 0.08) trend toward a better sleep quality during the NM phase. Objective sleep duration was not different between phases (FM: 398 ± 3 min, WM: 402 ± 3 min, NM: 403 ± 3 min; p = 0.31). No difference was found with regard to other PSG-derived parameters, EEG spectral analysis, or in diurnal cortisol levels. When considering only subjects with apnea/hypopnea index of <15/h and periodic leg movements index of <15/h, we found a trend toward shorter total sleep time during FM (FM: 402 ± 4, WM: 407 ± 4, NM: 415 ± 4 min; p = 0.06) and shorter-stage N2 duration (FM: 178 ± 3, WM: 182 ± 3, NM: 188 ± 3 min; p = 0.05).


CONCLUSIONS
Our large population-based study provides no evidence of a significant effect of lunar phases on human sleep.
Center for Investigation and Research in Sleep (CIRS), Lausanne University Hospital (CHUV), Lausanne, Switzerland.
José
J
Haba-Rubio
Department of Medicine, Internal Medicine, Lausanne University Hospital (CHUV) and Faculty of Biology and Medicine, Lausanne, Switzerland.
Pedro
P
Marques-Vidal
Center for Investigation and Research in Sleep (CIRS), Lausanne University Hospital (CHUV), Lausanne, Switzerland.
Nadia
N
Tobback
Center for Investigation and Research in Sleep (CIRS), Lausanne University Hospital (CHUV), Lausanne, Switzerland.
Daniela
D
Andries
Department of Psychiatry, Lausanne University Hospital (CHUV), Lausanne, Switzerland.
Martin
M
Preisig
Research Group Longitudinal and Intervention Research, Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Germany.
Christine
C
Kuehner
Department of Medicine, Internal Medicine, Lausanne University Hospital (CHUV) and Faculty of Biology and Medicine, Lausanne, Switzerland.
Peter
P
Vollenweider
Department of Medicine, Internal Medicine, Lausanne University Hospital (CHUV) and Faculty of Biology and Medicine, Lausanne, Switzerland.
Gérard
G
Waeber
Center for Integrative Genomics, Lausanne University, Lausanne, Switzerland.
Gianina
G
Luca
Center for Investigation and Research in Sleep (CIRS), Lausanne University Hospital (CHUV), Lausanne, Switzerland; Center for Integrative Genomics, Lausanne University, Lausanne, Switzerland.
Mehdi
M
Tafti
Center for Investigation and Research in Sleep (CIRS), Lausanne University Hospital (CHUV), Lausanne, Switzerland; Pulmonary Department, Lausanne University Hospital (CHUV), Lausanne, Switzerland. Electronic address: raphael.heinzer@chuv.ch.
Raphaël
R
Heinzer
D000328:Adult; D000368:Aged; D015331:Cohort Studies; D004569:Electroencephalography; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis; D008297:Male; D008875:Middle Aged; D016081:Moon; D017286:Polysomnography / Q000379:methods; D012463:Saliva / Q000737:chemistry; D012890:Sleep / Q000502:physiology*
D006854:Hydrocortisone
Cortisol; EEG spectral analysis; Moon; Sleep