Circulating miRNAs are associated with sleep duration in children/adolescents: results of the I.Family Study

It is commonly recognized that sleep is essential for children's health, and that insufficient sleep duration is associated with negative health outcomes. In humans, sleep duration and quality are influenced by genetic, environmental and social factors. Epigenetic mechanisms, likewise, regulate circadian rhythms and sleep patterns. In the present study, we aimed to identify circulating microRNAs associated with sleep duration in a subsample of normal-weight European children/adolescents (n=111) participating in the I.Family Study. Study subjects were divided into two groups based upon the self-reported sleep duration, according to the recommended amount of sleep for pediatric populations. Sleep needs for children <13 years were at least 9 hours per day, and for children >13 were at least 8 hours per day. There were group differences (short sleepers versus normal sleepers) in circulating levels of miR-26b-3p [mean (I.C.)] = 2.0 (1.3 - 2.7) versus 2.3 (1.9 - 2.7), p-value = 0.05 and miR-485-5p [mean (I.C.)] = 0.6 (0.3 - 0.9) versus 0.9 (0.7 - 1.0), p-value < 0.001 adjusting for country of origin, age, sex, pubertal status, screen time, and highest educational level of parents. Our findings show for the first time that the sleep duration reflects the profile of specific circulating microRNAs in school-aged children and adolescents. It is conceivable that epigenetic modifications, mainly related to circadian rhythm control, may be modulated or interfere with sleep duration.