Associations between Sleep Pattern and Quality and Cardiovascular Risk Factors among Macao School Students

Social jetlag and obesity: A systematic review and meta-analysis

Social jetlag, the weekly variation in sleep timing, is proposed to contribute to increased obesity risk, potentially because of the misalignment of behavioral cycles relative to the endogenous circadian timing system. This systematic review and meta-analysis aim to determine the association between social jetlag and adiposity-related measures using observational studies. We reviewed 477 references, of which 43 studies met inclusion criteria with a total sample size of 231,648. There was a positive association between social jetlag and body mass index (correlation coefficient [r]: 0.12; 95%CI, 0.07, 0.17; P < 0.001; I2  = 94.99%), fat mass (r: 0.10; 95%CI, 0.05, 0.15; P < 0.001; I2  = 0.00%), fat mass index (fat mass divided by height in meter squared, β: 0.14 kg/m2 ; 95%CI, 0.05, 0.23; P < 0.001; I2  = 56.50%), percent of body fat (r: 0.37; 95%CI, 0.33, 0.41; P < 0.001; I2  = 96.17%), waist circumference (r: 0.15; 95%CI, 0.06, 0.24; P = 0.001; I2  = 90.83%), and the risk of having overweight/obesity (odds ratio: 1.20; 95%CI, 1.02, 1.140; P = 0.039; I2  = 98.25%). Social jetlag is positively and consistently associated with multiple obesity-related anthropometric measures. Further studies are needed to test causality, underlying mechanisms, and whether obesity interventions based on increasing regularity of the sleep/wake cycle can aid in the battle against the obesity pandemic.

Adolescent sleep health in Africa: a scoping review protocol

INTRODUCTION

Problematic sleep is a major threat to health and quality of life among adolescents. Hence, to provide directions for research and interventions, there is a need to examine the literature on adolescent sleep health in Africa. However, available studies on adolescent sleep health in Africa have not been properly mapped. Thus, this scoping review aims to investigate the extent and type of available evidence concerning sleep health among adolescents in Africa and to highlight the relationship of adolescent sleep health with adverse mental health outcomes and cardiometabolic risk factors. The review will further highlight areas of agreement and controversies on adolescent sleep health, and identify evidence gaps that require research attention across the continent.

METHODS AND ANALYSIS

This scoping review will be conducted using Arksey and O'Malley's six-step procedure. Thus, we have prepared this protocol according to the framework for scoping reviews developed by the Joanna Briggs Institute. To identify eligible studies, we will search MEDLINE, Scopus, PsycINFO, AJOL, JSTOR, HINARI and Google Scholar. The review will include all published articles in English, French, Spanish, Portuguese and Italian languages on adolescent sleep health in Africa from the inception of the databases, while relevant information will be extracted from included studies using an adapted data extraction tool. The results will be presented using tables and charts as appropriate.

ETHICS AND DISSEMINATION

The scoping review does not require ethical approval because the publications to be used for the review are publicly available and the study does not involve contact with humans or other animals as research participants. Furthermore, clinical records will not be used for the study. Upon completion, findings from the study will be disseminated through presentations at scientific meetings and publication in a relevant peer-reviewed journal.

SCOPING REVIEW REGISTRATION

Open Science Framework (https://osf.io/5sjwq/).

Validation of the Entrainment Signal Regularity Index and associations with children's changes in BMI

OBJECTIVE

This study examined the validity of a novel metric of circadian health, the Entrainment Signal Regularity Index (ESRI), and its relationship to changes in BMI during the school year and summer.

METHODS

In a longitudinal observational data set, this study examined the relationship between ESRI score and children's (n = 119, 5- to 8-year-olds) sleep and physical activity levels during the school year and summer, differences in ESRI score during the school year and summer, and the association of ESRI score during the school year and summer with changes in BMI across those time periods.

RESULTS

The ESRI score was higher during the school year (0.70 ± 0.10) compared with summer (0.63 ± 0.11); t(111) = 5.484, p < 0.001. Whereas the ESRI score at the beginning of the school year did not significantly predict BMI change during the school year (β = 0.05 ± 0.09 SE, p = 0.57), having a higher ESRI score during summer predicted smaller increases in BMI during summer (β = -0.22 ± 0.10 SE, p = 0.03).

CONCLUSIONS

Overall, children demonstrated higher entrainment regularity during the school year compared with the summer. During summer, having a higher entrainment signal was associated with smaller changes in summertime BMI. This effect was independent of the effects of children's sleep midpoint, sleep regularity, and physical activity on children's BMI.

Sleep duration change from childhood to adulthood and adult depressive disorders in the Chinese population

BACKGROUND

Sleep deprivation may cause depressive disorders in both children and adults. However, the effects of sleep duration change from childhood to adulthood on adult depressive disorders are poorly documented. Using the China Family Panel Study (CFPS) data, we aimed to examine the association between sleep duration change from childhood to adulthood and adult depressive disorders in the Chinese population.

METHODS

Data were from 1172 children aged 10-15 years in 2010 who were followed up through 2018 based on the nationally representative and population-based CFPS. According to sleep duration in childhood and early adulthood, the sleep duration change was categorized into four groups: persistently insufficient sleep, sleep duration loss, sleep duration gain and persistently sufficient sleep.

RESULTS

After adjustment for potential covariates, compared with individuals with persistently sufficient sleep duration, those with sleep duration loss (OR = 1.98, 95% CI = 1.14-3.46) and persistently insufficient sleep (OR = 2.35, 95% CI = 1.43-3.88) had higher odds of depressive disorders in adulthood. In contrast, the odds of adult depressive disorders did not significantly increase in those with sleep duration gain (OR = 1.46, 95% CI = 0.88-2.41).

LIMITATIONS

Information on sleep duration was obtained through a questionnaire; the sample size of this study was not large; the generalizality of our findings to other populations should be caucious.

CONCLUSION

Persistently insufficient sleep duration and sleep duration loss from childhood to adulthood were associated with higher odds of adult depressive disorders, while those who were able to change their sleep duration from insufficient status to sufficient status didn't have an increased odds of adult depressive disorders.

Sleep onset, duration, or regularity: which matters most for child adiposity outcomes?

BACKGROUND/OBJECTIVES

Sleep measures, such as duration and onset timing, are associated with adiposity outcomes among children. Recent research among adults has considered variability in sleep and wake onset times, with the Sleep Regularity Index (SRI) as a comprehensive metric to measure shifts in sleep and wake onset times between days. However, little research has examined regularity and adiposity outcomes among children. This study examined the associations of three sleep measures (i.e., sleep duration, sleep onset time, and SRI) with three measures of adiposity (i.e., body mass index [BMI], waist circumference, and waist-to-height ratio [WHtR]) in a pediatric sample.

SUBJECTS/METHODS

Children (ages 4-13 years) who were part of the U.S. Newborn Epigenetic STudy (NEST) participated. Children (N = 144) wore an ActiGraph for 1 week. Sleep measures were estimated from actigraphy data. Weight, height, and waist circumference were measured by trained researchers. BMI and WHtR was calculated with the objectively measured waist and height values. Multiple linear regression models examined associations between child sleep and adiposity outcomes, controlling for race/ethnicity, child sex, age, mothers' BMI and sleep duration.

RESULTS

When considering sleep onset timing and duration, along with demographic covariates, sleep onset timing was not significantly associated with any of the three adiposity measures, but a longer duration was significantly associated with a lower BMI Z-score (β = -0.29, p < 0.001), waist circumference (β = -0.31, p < 0.001), and WHtR (β = -0.38, p < 0.001). When considering SRI and duration, duration remained significantly associated with the adiposity measures. The SRI and adiposity associations were in the expected direction, but were non-significant, except the SRI and WHtR association (β = -0.16, p = 0.077) was marginally non-significant.

CONCLUSIONS

Sleep duration was consistently associated with adiposity measures in children 4-13 years of age. Pediatric sleep interventions should focus first on elongating nighttime sleep duration, and examine if this improves child adiposity outcomes.

Sleep Status and the Associated Factors: A Large Cross-Sectional Study in Shaanxi Province, China

This study aimed at investigating the sleep status and its associated factors in Shaanxi province, China. We conducted a cross-sectional study among 11,399 subjects in Shaanxi Province, China. Data were collected via spot field questionnaire surveys. The contents included demographic characteristics, sleep status, lifestyles, disease history and other associated factors. Logistic regression analysis was used to estimate the effect of associated factors on sleep quality. A total of 11,036 subjects were included in the final analysis. In total, 12.8% of the participants had bad or very bad sleep. In the last month, 8.4% of the participants had difficulty in initiating sleep, 7.6% of the participants had difficulty in maintaining sleep, 8.8% of the participants suffered from awakening earlier and 10.3% of the participants had the problem of feeling sleepy during the day ≥3 times per week. Poorer sleep quality was associated with being female, being unmarried or without cohabiting with a boyfriend/girlfriend, being divorced or widowed, heart diseases, musculoskeletal diseases, concerns about their own health, drinking alcohol, taking hypnotics, and a longer daily screen time. Better sleep quality was associated with medium education level, high family monthly income, good self-reported health status, and having breakfast regularly. In conclusion, more than one in ten people did not sleep well and suffered from different sleep problems in Shaanxi, China. Sleep quality was associated with sex, marital status, educational level, family monthly income, heart disease, musculoskeletal diseases, degree of concerning about their own health, self-reported health status, drinking alcohol, having breakfast, taking hypnotics and daily screen time.

Association between Sleep Timing and Weight Status among 14- to 19-Year-Old Adolescents in Wuhan, China

This study examined the cross-sectional and longitudinal association of sleep timing with weight status in 14- to 19-year-old adolescents in Wuhan, China. A prospective school-based study was conducted in Wuhan, China between 28 May and 29 September 2019. Data on sociodemographic information, academic performance, diet, mental health status, physical activity, sleep characteristics, body weight, and height were collected. A linear regression model and binary logistic regression model were performed. A total of 1194 adolescents were included in the analysis. Adolescents who woke up before 05:45 had higher body mass index (BMI) Z-score (odds ratio (OR) with 95% confidence interval (CI) = 1.28 (1.05, 1.57), p = 0.02) and higher odds of overweight/obesity (odds ratio (OR) with 95% confidence interval (CI) = 1.74 (1.10, 2.76), p = 0.02) at baseline after fully adjustment for covariates, compared with those who woke up after 05:45. Longitudinal data showed a nonsignificant association between waking up time and change in BMI Z-score (p = 0.18). No association of bedtime with weight status was observed in this sample after full adjustment (p > 0.1). Earlier waking up time might contribute to overweight and obesity in adolescents; however, more data are needed to test and elucidate this relationship.