Objective: To explore the association between growth patterns and blood pressure in children and adolescents with different nutritional status. Methods: A total of 38 839 children and adolescents aged 6 to 8 years old were included in this study by stratified cluster sampling. The American Academy of Pediatrics 2017 Guideline was used to evaluate the blood pressure, the US 2000 CDC standard was used to determine different growth patterns, and the WHO Child and Adolescent Growth and Development Standard issued in 2007 was used to evaluate nutritional status. Variance analyses were used to compare the levels of systolic and diastolic blood pressure and growth patterns by nutritional status, and χ 2 test was used to compare the difference of prevalence. Multivariate Logistic regression model was used to analyze the association between growth patterns and blood pressure. Results: The proportion of normal growth, catch up growth and catch down growth was 33.2%, 41.6% and 25.2%, respectively. Under different growth patterns, systolic blood pressure (105.17±12.33) mm Hg and diastolic blood pressure (66.55±8.75) mm Hg of catch up growth were higher than those of normal growth and catch down growth. In overweight and obesity, the prevalence of hypertension (24.9%), high systolic blood pressure (18.9%) and high diastolic blood pressure (15.0%) in catch up growth were higher than those in normal growth and catch down growth ( P <0.05). The risk of catch up growth to hypertension was higher in overweight and obesity ( OR =1.18, 95% CI =1.06-1.31) than in normal children and adolescents ( OR =1.15, 95% CI =1.05-1.27). Conclusion In catch up growth children and adolescents, hypertension and high blood pressure are higher than normal growth and catch down growth. Overweight and obesity than normal children and adolescents have a higher risk of hypertension.

Objective: To analyze the trend of percentile changes in body composition among children and adolescents aged 7 to 18 by gender and age, and to provide a scientific basis for reference value. Methods: A stratified cluster random sampling method was used to select 1 585 children and adolescents from September to December 2020. Use the GAMLSS to estimate the P 25 , P 50 and P 75 percentile value of gender, age specific body fat percentage (BF%), fat mass index (FMI) and fat free mass (FFM). Results: In different age groups, body fat percentage of boys with normal nutritional status peaked at around 10-year old, among them, body fat percentage of 10-year old P 25 , P 50 and P 75 were 22.2%, 26.1% and 30.1%, respectively. Body fat percentage of obese boys was at a high level. Among girls, body fat percentage under different nutritional status did not change. With the increase of age, fat mass index plateaued slightly in normal and overweight boys. However, in obese boys, with the increase of age, FMI gradually increased with the increase of percentile, while the value of FMI gradually decreased in girls. Whether in boys or girls, with the increase of age, fat free mass index shows an increasing trend, and boys increase faster. Conclusion Under different nutritional status, there are differences in the percentile value of body fat percentage, fat mass index and fat free mass by gender and age, which can provide a scientific basis for reference value of body composition in children and adolescents.

Objective: To analyze the association between sleep duration and social anxiety in Chinese children and adolescents to provide evidence for promoting healthy lifestyle and mental health in children and adolescents. Methods: A total of 1 145 children and adolescents aged 7-16 were recruited by cluster random sampling in Beijing in 2020, and received a series of body measurements and questionnaire survey. Social Anxiety Scale for Children (SASC) and Pittsburgh Sleep Quality Index (PSQI) were used to evaluate the social anxiety symptoms and sleep duration of children and adolescents. T test was used to compare the differences of social anxiety level in different groups, and multivariate linear regression analysis was used to analyze the relationship between sleep duration and social anxiety. Results: The average score of social anxiety was (5.47±4.18). The social anxiety score of girls, participants aged 13-16, with insufficient physical activity and insufficient sleep duration were higher ( t =-4.34, -6.14, 3.35, 2.93, P < 0.05). The results of multivariate linear regression model showed that after adjusting confounding factors, social anxiety decreased by 0.78 for each additional hour of sleep duration ( β =-0.78, 95% CI =-1.03--0.54, P <0.01), with 0.60 in boys (95% CI = -0.95 --0.25), 0.90 in girls (95% CI =-1.24--0.56), 0.75 among participants aged 7-12 (95% CI =-1.11--0.40) and 0.76 among participants aged 13~16 (95% CI =-1.11--0.41)( P <0.01), respectively. Social anxiety among participants who were not over weight or obese decreased by 0.78(95% CI =-1.09--0.48) and 0.81 among overweight and obese group (95% CI =-1.22- -0.41 )( P <0.01) for each additional hour of sleep duration, respectively. Conclusion Substantial differences in social anxiety are observed in children and adolescents by gender, age group and nutritional status. Sufficient sleep duration is significantly related to the decrease of social anxiety, and improve the overall level of student mental health.