Lunar tractive forces and renal stone incidence

Background. Several factors are implicated in renal stone formation and peak incidence of renal colic admissions to emergency departments (ED). Little is known about the influence of potential environmental triggers such as lunar gravitational forces. We conducted a retrospective study to test the hypothesis that the incidence of symptomatic renal colics increases at the time of the full and new moon because of increased lunar gravitational forces. Methods. We analysed 1500 patients who attended our ED between 2000 and 2010 because of nephrolithiasis-induced renal colic. The lunar phases were defined as full moon ± 1 day, new moon ± 1 day, and the days in-between as "normal" days. Results. During this 11-year period, 156 cases of acute nephrolithiasis were diagnosed at the time of a full moon and 146 at the time of a new moon (mean of 0.4 per day for both). 1198 cases were diagnosed on "normal" days (mean 0.4 per day). The incidence of nephrolithiasis in peak and other lunar gravitational phases, the circannual variation and the gender-specific analysis showed no statistically significant differences. Conclusion. In this adequate powered longitudinal study, changes in tractive force during the different lunar phases did not influence the incidence of renal colic admissions in emergency department.

Sleepless night, the moon is bright: longitudinal study of lunar phase and sleep

Popular belief holds that the lunar cycle affects human physiology, behaviour and health. We examined the influence of moon phase on sleep duration in a secondary analysis of a feasibility study of mobile telephone base stations and sleep quality. We studied 31 volunteers (18 women and 13 men, mean age 50 years) from a suburban area of Switzerland longitudinally over 6 weeks, including two full moons. Subjective sleep duration was calculated from sleep diary data. Data were analysed using multiple linear regression models with random effects. Mean sleep duration was 6 h 49 min. Subjective sleep duration varied with the lunar cycle, from 6 h 41 min at full moon to 7 h 00 min at new moon (P < 0.001). Average sleep duration was shortened by 68 min during the week compared with weekends (P < 0.001). Men slept 17 min longer than women (P < 0.001) and sleep duration decreased with age (P < 0.001). There was also evidence that rating of fatigue in the morning was associated with moon phase, with more tiredness (P = 0.027) at full moon. The study was designed for other purposes and the association between lunar cycle and sleep duration will need to be confirmed in further studies.