Erratum

Physical activity, sleep duration and metabolic health in children fluctuate with the lunar cycle: science behind the myth

A. Sjödin, M. F. Hjorth, C. T. Damsgaard, C. Ritz, A. Astrup and K. F. Michaelsen

In the above‐mentioned article, the authors have identified an error. Beta (95%CI) values from the log‐transformed variables (HOMA‐IR, Insulin, and Leptin) presented in Table 1 were incorrectly back‐transformed. First, the estimated difference in HOMA‐IR between full moon and half moon should not be 0.03 (95% CI: 0.005;0.05) as stated in the article but instead be 0.08 (95% CI: 0.01;0.14) and the estimated difference in HOMA‐IR between full moon and new moon should not be 0.05 (95% CI: 0.02;0.08) as stated in the article but instead be 0.14 (95% CI: 0.05;0.22). Secondly, the estimated difference in Insulin between full moon and half moon should not be 0.09 (95% CI: 0.004;0.18) as stated in the article but instead be 1.85 (95% CI: 0.08;3.62) and the estimated difference in Insulin between full moon and new moon should not be 0.15 (95% CI: 0.03;0.27) as stated in the article but instead be 3.03 (95% CI: 0.64;5.41). Finally, the estimated difference in Leptin between full moon and half moon should not be 1.2 (95% CI: 0.5;1.8) as stated in the article but instead be 434 (95% CI: 191;676) and the estimated difference in Leptin between full moon and new moon should not be 0.7 (95% CI: −0.1;1.6) as stated in the article but instead be 276 (95% CI: −52;605). All p‐values are unchanged. These changes do not change the overall conclusions of the article.

Table 1.

Behaviours and metabolic variables according to lunar phases (n = 751–793)

Variables	Observations	Mean ± standard deviation or median (interquartile range)	Full moona – half moonb beta (95 % CI)	Full moona – new moonc beta (95 % CI)
Behaviours
Moderate‐to‐vigorous PA (min per day)	13 464	41 (21; 68)	−5.0 (−6.5; −3.6)**	−3.2 (−4.7; −1.7)**
Light PA (min per day)	13 464	375 ± 80	0.1 (−3.0; 3.2)	1.7 (−1.4; 4.9)
Sedentary time (min per day)	13 464	477 ± 99	1.4 (−2.6; 5.4)	−1.9 (−6.0; 2.2)
Sleep duration (min per night)	13 762	550 ± 49	2.4 (0.3; 4.4)*	4.1 (2.0; 6.2)**
Metabolic variables
HOMAIR	2005	1.46 (1.03; 2.05)	0.08 (0.01; 0.14)*	0.14 (0.05; 0.22)*
Insulin (pmol L−1)	2005	43.8 (31.6; 60.5)	1.85 (0.08; 3.62)*, e	3.03 (0.64; 5.41)*
Glucose (mmol L−1)	2057	5.2 ± 0.5	0.05 (0.005; 0.10)*, e	0.12 (0.06; 0.18)**
Mean arterial blood pressure (mmHg)	2148	79.5 ± 6.0	0.6 (0.1; 1.1)*	0.8 (0.2; 1.4)*
Diastolic blood pressure (mmHg)	2148	66.0 ± 6.4	0.7 (0.2; 1.2)*	0.9 (0.3; 1.6)*
Systolic blood pressure (mmHg)	2148	106.5 ± 7.6	0.4 (−0.2; 0.9)	0.4 (−0.3; 1.2)
Ghrelin (pg mL−1)	2028	996 ± 383	−29 (−46; −13)**	−5 (−28; 18)
Leptin (pg mL−1)d	2017	4013 (2223; 8056)	434 (191; 676)**	276 (−52; 605)

Data are presented as unstandardized regression coefficients (β) or % difference with 95% confidence intervals using a linear mixed model with school, class and subject as random effects and weekday, month, age, gender, Tanner stage, number of parents born in Denmark and highest education of parents as fixed factors.

^aFull moon ±4 d (Include 25 to 35% of the observations in all models).

^b±5–9 d from full moon (Include 35 to 36% of the observations in all models).

^c±10–14 d from full moon (Include 29 to 39% of the observations in all models).

^dAdditionally adjusted for total body fat.

^eSignificant associations vanished after Bonferroni adjustments.

*P < 0.05; **P < 0.001 indicate significant difference from full moon ±4 d.

HOMA_IR, homeostatic model assessment of insulin resistance; PA, physical activity.