Indexed on: 29 Apr '18Published on: 15 Apr '18Published in: Sleep Medicine
Publication date: Available online 12 April 2018 Source:Sleep Medicine Author(s): Brenda J. de Zwart, Joline W.J. Beulens, Petra Elders, Femke Rutters Objective Social jetlag, a form of chronic circadian misalignment, has previously been associated with obesity in adults. We aimed to investigate the association between social jetlag and obesity-related characteristics in Dutch adolescents in 1 year. Methods We analysed data of 83 adolescents, who were recruited from a Dutch cohort born between the years 1990 and 1993. We determined anthropometric measurements, body composition, physical activity, hours of television use, and self-reported sleep duration. Using linear regression models, we assessed the association between social jetlag, defined as more than a 1-hour difference between the midpoint of sleep during weekdays and weekend days, and body mass index (BMI), body fat percentage, and waist circumference at baseline and after 1 year. We corrected the analysis for sex, sleep, physical activity, and hours of television use. Results We observed that social jetlag was highly prevalent, with only 13% of the adolescents reporting no social jetlag (≤1 hour), whereas 29% and 58% reported a social jetlag of >1 to 2 hours and ≥2 hours. In a cross-sectional analysis, we observed at baseline a significant higher BMI in the group with no social jetlag, compared to the group with >1- to 2-hour and ≥2-hour social jetlag after adjustment for sex (−0.81 kg/m2, 95% confidence interval = −3.1 to 1.4; and −2.09 kg/m2, 95% confidence interval = −4.1 to −0.1). This association remained significant after correction for the other possible confounders. No significant associations were observed between social jetlag at baseline and changes in the obesity-related characteristics over 1 year. Conclusion Our pilot data showed that social jetlag is highly prevalent in adolescents, with social jetlag associated with a lower BMI; however, in this small group, social jetlag was not associated with changes in obesity-related characteristics over time.