Middle childhood and adolescence sleep duration and behavior problems in adolescence.

We examined the associations of middle childhood and adolescence nighttime sleep duration with adolescence internalizing and externalizing behavior problems per the Youth Self-Report (YSR) and the Child Behavior Checklist (CBCL) questionnaires, in a cohort of 889 Colombian schoolchildren. We estimated adjusted differences with 95% confidence intervals (CI) in mean behavior problem t-scores in standardized units between recommended sleep duration categories and as a continuous exposure using multiple linear regression and restricted cubic spline models, respectively. Compared with sleep duration within recommendations, middle childhood sleep above recommendations was related to 4.6 (95% CI: 1.6, 7.6; p = .004) and 5.4 (95% CI: 1.2, 9.7; p = .01) adjusted units higher YSR and CBCL externalizing problem scores, respectively. In continuous exposure analyses, this association seemed restricted to children aged ≥11 years. Longer sleep, both in categories and as a continuous exposure, was also associated with increased CBCL internalizing problems. Results did not differ by sex or weekend/weekday sleep. Sleeping under recommendations in middle childhood was not significantly related to behavior problems; nevertheless, shorter sleep in adolescence, in both categorical and continuous scales, was significantly related to behavior problems. In conclusion, behavior problems in adolescence are associated with longer sleep in middle childhood and shorter sleep in adolescence.

Association between sleep duration, fat mass, lean mass and obesity in Korean adults: the fourth and fifth Korea National Health and Nutrition Examination Surveys.

This study investigated the association between sleep duration, fat mass, lean mass and obesity. Participants of this cross-sectional study were 16 905 adults included into the 4th and 5th Korea National Health and Nutrition Examination Surveys. Sleep duration was assessed by self-reported survey and categorized into ≤ 5, 6, 7, 8 and ≥ 9 h per day. The group reporting 7 h of sleep per day (comprised of those sleeping 7-8 h per day) was used as the reference group. Body composition was measured by dual X-ray absorptiometry (DEXA). Obesity was defined based on the criteria from the Korean Society for the Study of Obesity. Least-squares means of fat mass index (FMI) and lean mass index (LMI) adjusted for age, employment status, comorbidities and physical activity were used to assess the relation between sleep duration and body composition. Multivariable logistic regression was used to calculate the adjusted odds ratios (aOR) and 95% confidence intervals (95% CI) of obesity according to sleep duration after adjusting for sociodemographic and health-related factors. After adjustment, FMI increased with fewer hours of sleep (P for trend: < 0.001) and LMI decreased with more hours of sleep (P for trend: 0.011). Compared to the reference group, sleep-deprived individuals were 1.22 times more likely to have general obesity (aOR: 1.22; 95% CI: 1.03-1.45) and 1.32 times more likely to have abdominal obesity (aOR: 1.32; 95% CI: 1.10-1.58). Our findings suggest that sleep deprivation might be related to an increase of fat mass and obesity, while oversleeping could be linked to a reduction of lean mass.

Factors Related to Oversleeping in Korean Young Adults, with a Focus on Sociodemographic Factors.

Young adults the year after high school experience changes in lifestyle and circumstances and tend to experience more oversleeping. However, there are few studies on oversleeping in young adults. This study aims to identify the sociodemographic factors related to oversleeping among young adults in Korea using nationally representative data. This study analyzed self-reported and cross-sectional data in 2016 from a sample of 1876 participants from the Korean Children and Youth Panel Survey, which included respondents one year after high school graduation. Oversleeping was defined as sleeping 9 or more hours a day on average. Logistic regression models were analyzed to test a multivariate association between independent sociodemographic variables and oversleeping. Over one-tenth of young adults reported oversleeping. Oversleeping was associated with household income (OR = 0.99, p = 0.011) and smoking (OR = 1.52, p = 0.041). In addition, when compared to non-working college students, college students who were working (OR = 2.58, p = 0.021), non-students who were working (OR = 1.68, p = 0.048), and non-students who were not working (OR = 3.07, p < 0.001) were more likely to report oversleeping. Oversleeping among young adults was associated with major sociodemographic factors including household income (-), smoking (+), and academic and working status (+). These findings suggest the significant role of sociodemographic factors as predictors of oversleeping and emphasize the importance of examining various factors to achieve a better understanding of oversleeping in young adults.