Childhood asthma and obesity have posed a parallel epidemic over the past few decades. However, whether asthma diagnosis is associated with obesity, and what the roles of lifestyle factors play in this relationship, remained unclarified. This study aimed to investigate the association between asthma and weight status in Chinese children and explore the potential mediating and/or modifying roles of lifestyle factors in the association. In this cross-sectional study, 16,837 children aged 6–12 years were recruited from Guangzhou, China. Participants’ information on physician-diagnosed asthma was collected from parents, and data on physical activity, screen time, and sleeping were reported in a validated questionnaire. Height and weight were objectively measured, and weight status was classified by body mass index (BMI). Multiple logistic regression analysis and mediation analysis were used. Results showed that asthmatic children were at significantly higher risk of obesity (odds ratio (OR) 1.51, 95% confidence interval (CI) 1.03, 2.21) compared with non-asthmatic children. More importantly, this increased risk was even greater in children with moderate-to-vigorous physical activity <60 min/d and children with screen time >2 h/d (both Pinteraction < 0.05). Also, a positive relationship of asthma with overweight was found in children with screen time >2 h/d (OR 3.92, 95% CI 1.56, 9.88), while a negative association was observed between asthma and underweight in children aged 9–12 years (OR 0.23, 95% CI 0.06, 0.92). Mediation analysis indicated that these associations were not mediated by physical activity, screen time, or sleeping. The findings suggested that physician-diagnosed asthma was associated with higher risks of overweight and obesity, and these risks might be exacerbated by insufficient physical activity and prolonged screen time.

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Childhood and adolescent overweight and obesity are increasing in China, but limited information is available on its secular trends in Guangzhou. In this cross-sectional study, ten-wave successive data were obtained from the physical fitness surveillance for students in Guangzhou from 2003 to 2012. A total of 2,619,154 urban students aged 7–18 years were included. The age-standardized prevalence of overweight and obesity increased significantly over the period: overweight rose from 10.15% to 14.07% in boys and 6.39% to 8.11% in girls, while obesity increased from 5.65% to 8.31% for boys and 3.43% to 4.12% for girls, respectively (P < 0.05). The increasing trend was significant across almost all age-sex-specific groups (P < 0.05), especially in the last five years. The prevalence of overweight and obesity grew continuously in both sexes, but the pace of change for boys were faster than that for girls. The highest prevalence of overweight was found among 10- to 12-year-old boys, that of obesity among 7- to 9-year-old boys and girls. In conclusion, overweight and obesity have increased significantly among urban children and adolescents in Guangzhou during 2003–2012. Further analysis of influencing factors and comprehensive interventions are urgently needed to combat the obesity epidemic among urban children and adolescents in Guangzhou.

Objective Childhood is a critical period for brain development. However, it remains unknown whether the behaviors in a typical 24-h day are related to children’s executive function (EF). This study aimed to investigate the relationship between the 24-h movement guidelines and children’s EF. Method Children aged 7–12 years (n = 376) were studied in 2017 in China. Physical activity (PA) was accelerometer-derived, while screen time (ST) and sleep duration were self-reported. Meeting the 24-h movement guidelines was defined as: 1) ≥ 60 min/day of moderate-to-vigorous PA; 2) ≤ 2 h/day of recreational ST; 3) 9–11 h/night of sleep. EF was assessed by the Wisconsin Card Sorting Test (WCST). Number of completed categories (CC), shifting efficiency (SE), non-perseverative errors (NPE), and failure to maintain set (FMS) were used to measure four processes of EF, respectively represented global performance, cognitive flexibility, efficiency in rule discovery, and sustained attention. Generalized linear mixed models (GLMM) were completed to explore the associations of meeting the PA, ST, and sleep duration recommendations with four processes of EF. Results Statistically significant positive associations were observed between the number of guidelines met, regarded as a continuous variable, with CC [β = 0.343 (95% confidence interval [CI]: 0.125, 0.561)] and SE [β = 4.028 (95% CI: 0.328, 7.727)], while number of guidelines met negatively related to NPE [β =  − 4.377 (95% CI:-7.952,-0.802)]. Participants not meeting the two recommendations for PA and sleep duration had lower scores in CC [β = -0.636(95% CI:-1.125,-0.147)] and SE [β = -10.610 (95% CI:-18.794,-2.425)] compared with those meeting the two, suggesting inferior global performance and worse efficiency in rule discovery. However, ST recommendation had no significant association with any processes of EF. Conclusion Meeting more recommendations of the 24-h movement guidelines was associated with superior EF in children. Specifically, more PA and healthy sleep duration should be encouraged to promote children’s EF.

Study Objectives: Although weekend catch-up sleep is common among children, the association between weekend catch-up sleep and executive functions remains unclear. We aimed to determine whether weekend catch-up sleep was related to executive functions in school-aged children. Methods: We analyzed data for 4,699 children (9.00 years ± 1.73 years old, 52.9% boys) from 5 primary schools in Guangzhou, China. Executive functions performance was examined by the Behavior Rating Inventory of Executive Function Parent Form. Validated self-report questionnaires were used to assess sleep status, socioeconomic status, and health behaviors. Multiple linear regression analyses were used to assess the association of weekend catch-up sleep duration with executive functions. Results: Weekday sleep was negatively associated with scores on three composite indices (Behavioral Regulation Index, Metacognition Index, Global Executive Composite), while weekend catch-up sleep was positively associated with them. Children with < 9 hours weekday sleep duration had higher scores in all indices, and there was no correlation between weekend catch-up sleep and scores of all indices (P > .05). For children who slept ≥ 9 hours on weekdays, weekend catch-up sleep of more than 1 hour was associated with increased scores of Behavioral Regulation Index, Metacognition Index, and Global Executive Composite (P < .05). There was no interaction between sex, age, and weekend catch-up sleep and executive functions (P > .05). Conclusions: Weekend catch-up sleep could not restore the executive functions deficits related to short weekday sleep. Weekend catch-up sleep over 1 hour may have adverse effects on executive functions in school-aged children.