Does the lunar cycle affect our sleep? An analysis of the circa-lunar periodicity in sleep’s architecture in Buenos Aires, Argentina

Recent studies have examined the relationship between the lunar cycle and human sleep using self-report, actigraphy, and polysomnography data. In this study, we extend this research by analyzing objective sleep parameters, measured with polysomnography, in people with suspected or diagnosed sleep disorders in Buenos Aires, Argentina. The sample included 955 participants (421 women and 534 men; mean age = 51.5 ± 15.8 years; range 18-89). REM percentage was significantly higher during new moon (NM) than full moon (FM) (17.8% NM vs. 16.2% FM, p<0.05), whereas nREM (82.2% NM vs. 83.9% FM, p<0.05) and N1 (2.4% NM vs. 3.3% FM, p < 0.05) percentages were lower. Men showed a higher percentage of stage N2 sleep than women in NM (61.7% vs 56.3%, p<0.01), whereas women showed higher N3 than men during both FM (22.4% vs 18.6%, p<0.01) and NM (23.7% vs 18.0%, p<0.001). We also compared sleep metrics among women under and over 50 years of age across lunar phases. Women over 50 showed a lower REM percentage (≈4% less, p< 0.01) and higher nREM percentage (≈4% more, p<0.01) during FM, while women under 50 had higher sleep efficiency than women over 50, although efficiency decreased by 4% during FM (p<0.05). These preliminary findings suggest that sex and age may be relevant factors when examining associations between lunar phase and sleep architecture in individuals with suspected or diagnosed sleep disorders.