ObjectiveTo test the independent and interactive associations of physical activity (PA) and screen time (ST) with self-reported mental health and sleep quality among Chinese college students.MethodData were collected in October, 2013. The gender, age, residential background, body mass index (BMI), perceived family economy and perceived study burden were obtained from a total of 4747 college students (41.6% males and 58.4% females). The outcomes were self-reported PA status, ST, anxiety, depression, psychopathological symptoms and sleep quality. Analyses were conducted with logistic regression models.ResultsOverall, 16.3%, 15.9% and 17.3% of the students had psychological problems, such as anxiety, depression and psychopathological symptoms, respectively. The prevalence of poor sleep quality was 9.8%. High ST was significantly positively associated with anxiety (OR=1.38, 95%CI: 1.15-1.65), depression (OR=1.76, 95%CI: 1.47-2.09), psychopathological symptoms (OR=1.69, 95%CI: 1.43-2.01) and poor sleep quality (OR=1.32, 95%CI: 1.06-1.65). High PA was insignificantly negatively associated with anxiety, depression, psychopathological symptoms and poor sleep. Low PA and high ST were independently and interactively associated with increased risks of mental health problems and poor sleep quality (p<0.05 for all).ConclusionInterventions are needed to reduce ST and increase PA in the lifestyles of young people. Future research should develop and measure the impacts of interventions and their potential consequences on sleep, health, and well being.

The purpose of this study was to evaluate the relationships between screen time (ST), nighttime sleep duration, and behavioural problems in a sample of preschool children in China. A sample of 8900 children aged 3-6 years was enrolled from 35 kindergartens, in four cities, in two provinces, in China to evaluate the relationships between ST, nighttime sleep duration, and behavioural problems. Children's ST and nighttime sleep duration were assessed by questionnaires completed by parents or guardians. Behavioural problems were assessed using the Strengths and Difficulties Questionnaire (SDQ), and the Clancy Autism Behaviour Scale (CABS). Multivariate analysis was used to assess the associations between ST, nighttime sleep duration, and behavioural problems. The total SDQ and CABS scores were higher in children with ST ≥2 h/day and sleep duration <9.15 h/day (a P < 0.001 for all). After adjusting for potential confounders, children with ST ≥2 h/day had a significantly increased risk of having total difficulties, emotional symptoms, conduct problems, hyperactivity, peer problems, and prosocial problems, as well as behavioural symptoms of autism spectrum disorder. Similar results were found in children with sleep duration <9.15 h/day. No significantly increased risk of emotional symptoms was observed for short sleep duration. Preschool children with more ST and short nighttime sleep duration were significantly more likely to have behavioural problems. These results may contribute to a better understanding of prevention and intervention for psychosocial problems in children.

Problematic mobile phone use (PMPU) is a risk factor for both adolescents’ sleep quality and mental health. It is important to examine the potential negative health effects of PMPU exposure. This study aims to evaluate PMPU and its association with mental health in Chinese college students. Furthermore, we investigated how sleep quality influences this association. In 2013, we collected data regarding participants’ PMPU, sleep quality, and mental health (psychopathological symptoms, anxiety, and depressive symptoms) by standardized questionnaires in 4747 college students. Multivariate logistic regression analysis was applied to assess independent effects and interactions of PMPU and sleep quality with mental health. PMPU and poor sleep quality were observed in 28.2% and 9.8% of participants, respectively. Adjusted logistic regression models suggested independent associations of PMPU and sleep quality with mental health (p < 0.001). Further regression analyses suggested a significant interaction between these measures (p < 0.001). The study highlights that poor sleep quality may play a more significant role in increasing the risk of mental health problems in students with PMPU than in those without PMPU.

ObjectivesWe examined the relationships between screen time (ST) and mental health problems and also increment of ST and progression of mental health problems in a college-based sample of Chinese youth.MethodsWe assessed 2521 Chinese college freshmen from October 2013 to December 2014. At baseline, the mean age of participants was 18.43 years (SD 0.96 years), and 1215 (48.2%) participants reported ST >2 h/day. We estimated multivariable-adjusted ORs by using logistic regression models for the risk of developing mental health problems (anxiety, depression and psychopathological symptoms) and/or progression of these problems, according to baseline ST exposure and changes in exposure at follow-up.ResultsAt baseline, when ST >2 h/day was compared with ST ≤2 h/day, the OR was 1.38 (95% CI 1.15 to 1.65) for anxiety, 1.55 (95% CI 1.25 to 1.93) for depression and 1.49 (95% CI 1.22 to 1.83) for psychopathological symptoms. The results remained unchanged for depressive and psychopathological symptoms but not for anxiety, after additional adjustment for sex, age, residential background, body mass index, perceived family economy, sleep quality, smoking, alcohol intake, exercise after school and physical activity. When participants who had increased their ST exposure to >2 h/day were compared with those with no change and ST ≤2 h/day, the OR was 1.78 (95% CI 1.12 to 2.83) for anxiety, 1.92 (95% CI 1.23 to 2.83) for depression and 1.93 (95% CI 1.16 to 3.21) for psychopathological symptoms. These associations also remained after additional adjustment.ConclusionsThe overall effects are consistent yet small for ST/ST increment on mental health problems and its progression. Given the small effect size of the current results, it remains unclear the degree to which ST is a practically significant risk factor for mental health outcomes. Future studies of high quality are necessary to further examine this association and the direction of causality.

BackgroundThe increase rates of cesarean section (CS) occurred at the same period as the dramatic increase of childhood overweight/obesity. In China, cesarean section rates have exponentially increased in the last 20 years and they now exceed World Health Organization (WHO) recommendation. Such high rates demand an understanding to the long-term consequences on child health. We aim to examine the association between CS and risk of overweight and obesity among preschool children.MethodWe recruited 9103 children from 35 kindergartens in 4 cities located in East China. Children anthropometric measurements were taken in person by trained personnel. The mode of delivery was classified as vaginal or CS, in sub-analyses we divided cesarean delivery into elective or non-elective. The mode of delivery and other parental information were self-reported by parents. Multivariate logistic regression analysis was used to examine the associations.ResultsIn our cross-sectional study of 8900 preschool children aged 3–6 years, 67.3 % were born via CS, of whom 15.7 % were obese. Cesarean delivery was significantly associated with the risk of overweight [OR 1.24; (95 % CI 1.07–1.44); p = 0.003], and the risk of obesity [OR 1.29; (95 % CI 1.13–1.49); p < 0.001] in preschool children. After adjusted for child characteristics, parental factors and family income, the odd of overweight was 1.35 and of obesity was 1.25 in children delivered by elective CS.ConclusionThe associations between CS and overweight/obesity in preschool children are influenced by potential confounders. Both children delivered by elective or non-elective CS are at increased risk of overweight/obesity. Potential consequences of CS on the health of the children should be discussed among both health care professionals and childbearing women.