Associations of sleep duration and social jetlag with cardiometabolic risk factors in the study of Latino youth

Abstract

Objective: We investigated associations of sleep duration and social jetlag with cardiometabolic outcomes.Participants: Boys and girls aged 8 to 16 years from the Hispanic Community Health Study/ Study of Latino (HCHS/SOL) Youth.Measurements: Participants (n=1,208) completed a clinical examination where anthropometric characteristics, health behaviors and health history were measured. Sleep duration was calculated as the weighted average of self-reported weekday and weekend bedtimes and wake times and categorized into age-specific cutoffs for short vs. normal sleep. "Social jetlag" was defined as the absolute difference in the midpoint of the sleep period between weekdays and weekends, measured continuously and dichotomized (≥2 hours), with higher values indicating more displacement of sleep timing across the week. Regression models tested the associations between sleep measures (separately) and cardiometabolic outcomes [e.g. healthy eating index (0-100), physical activity-minutes per week, obesity, diabetes, hypertension] after adjustment for covariates. Results:The average sleep duration was 9.5 hours (95% confidence interval: 9.3, 9.6) and the mean social jetlag was 2.5 (2.4, 2.7) hours. Participants with social jetlag reported more physical activity [β=34.8 (13.14), P<0.01], had a higher healthy eating index [β=1.77 (0.87), P<0.05] and Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Relationships between Sleep Duration, Timing, Consistency, and Chronotype with Myopia among School-Aged Children

“…Our study revealed a far less than 1 hour's jetlag of sleep midpoint between weekdays and free days, suggesting social jetlag is quite mild in our sampled school-aged children. Similar to our finding, the most recent study did not establish a relationship between social jetlag and negative health outcome [ 39 ]. In summary, the methods and thresholds for characterizing biologically social jetlag in children are not well understood, and further exploration is needed.…”

“…Differences in sleep timing (e.g., bedtime, rise time, and the midpoint of sleep) between workday and free day simulate the effects of jet lag, defined as “social jetlag” [ 36 ], reflecting the discrepancy between social and circadian rhythms [ 22 ]. The existing evidence indicates that, among adolescents, high social jetlag is associated with behavioral problems and obesity [ 37 , 38 ], which are not observed among children [ 39 ]. There is a shift in biological preference for later sleep timing and higher social jetlag during adolescence; by contrast, the sleep pattern is relatively stable and regular during school age [ 40 ].…”

Associations of Social Jetlag with Dietary Behavior, Physical Activity and Obesity among Chinese Adolescents

“…We found that 54.64% of the adolescents were identified to have SJL (≥1 h). A previous cross-sectional study of Chinese children that reported a relatively low proportion of SJL in the studied populations [ 20 ] and another study focused on Hispanic adolescents aged 8–16 years indicated that SJL occurred at the rate of 52.3% [ 19 ]. Besides, a prior American study that found that more than 80% of the adolescents had SJL [ 13 ].…”

“…Another recent cross-sectional study pointed out that SJL is related to a higher frequency of sugar-sweetened beverage consumption [ 13 ]. Also, a study indicated a positive association between SJL and increased moderate to vigorous physical activity (MVPA) [ 19 ]. Understanding how SJL relates to dietary behavior and physical activity may aid in the prevention of obesity.…”

A Model of Adolescent Sleep Health and Risk for Type 2 Diabetes

“…Another study found that social jetlag was associated with lower odds of healthy dietary behaviors (e.g., breakfast consumption, fruit and vegetable intake, and fast food consumption, and higher BMI in a study of over 3000 adolescents) [78]. Conversely, social jetlag was associated with healthier lifestyle behaviors (physical activity and dietary intake) and lower BMI in two other studies of youth [74,79]. Given the high prevalence, additional research clarifying the impact of social jetlag on metabolic risk factors in adolescents is needed.…”