Abstract The prevalence of cardiometabolic risk factors at early lifecycle stages is higher than ever before, early identification and stratified intervention are critical to slowing down disease progression and reducing cardiovascular disease risk burden in adulthood. The implementation of stratified interventions to address the co-prevalence of cardiometabolic risk factors can reduce health expenditure and increase social capital. Guided by the policies and characteristics inherent to the growth and development of Chinese children, and nurtured and inspired by prestigious child cohorts around the world, we aim to carry out a precisely measured child cohort study that uses rigorous indicators to assess child health. We wish to produce detailed evidence that can identify cardiometabolic risk factors during childhood, so as to develop early warning and informed stratified intervention strategies, which can thereby reduce the burden of cardiovascular disease in China from childhood to adulthood and improve quality of life.

Abstract The health of children and adolescents is not only related to the growth and wellbeing of individuals, but also to the construction and development of countries. This study reviewed policies that were issued by the central government since the founding of New China which focused on the prevention and treatment of common diseases among school-age children and adolescents. The results revealed that, since the founding of New China, policies for the prevention and control of common diseases among school-age children and adolescents increased in number, and they began to focus on specific rather than general health problems. A gradual emphasis was placed on the specific implementation of prevention and control measures, rather than on guiding principles. Increasingly more attention has been paid to the prevention and treatment of common diseases among school-age children and adolescents.

Objective: To explore sex differences between weight and systolic blood pressure (SBP) changes among school-age children and adolescents in Beijing, and to provide a basis for priority intervention to control the rapid growth of body weight and blood pressure. Methods: Anthropometric measurement data of 70 288 children and adolescents from primary and high schools in Shunyi District were collected from 2009 to 2018, and a longitudinal dataset with complete data related to weight and BP after individual data linkage was compiled. The age-specific weight and SBP growth rates were calculated, and a linear mixed-effects model was used to identify sex differences in chronological growth rates. Results: Weight and SBP increased with age in both boys and girls, and the mean weight and SBP were higher in boys than in girls across all age groups. The result of the linear mixed-effects model indicated apparent sex differences in weight and SBP growth rates, with an age and sex interaction term(β=-0.35, -0.40, P<0.01). The age at peak weight velocity (PWA) was 12 years old and the age at peak SBP velocity was 13 years old in boys, which occurred one and three years later than for girls, respectively. In addition, the peak weight and SBP velocity were higher in boys than in girls. The curves of the SBP growth rate adjusted for the PWA, showed that the peak SBP velocity occurred two years before PWA and the second peak SBP velocity occurred at the PWA, which indicated "double peaks" in both boys and girls. The SBP growth rate was always higher in boys than in girls, and the rates declined after PWA. Conclusion Sex differences in weight and SBP growth rates were persistent and obvious in school-age children and adolescents in Beijing and the change in SBP was highly time synchronized with the increase in weight.

Objective: To explore differences in the detection rate of elevated blood pressure (BP) in children aged 6-8 years old, and to verify the apparent existence of white-coat hypertension (BP) in children. Methods: Based on census data(PROC), and three subsequent BP readings were taken during follow-ups which were carried out from October 2018 to June 2019. A total of 1 785 children were included in the present study. Using updating blood pressure reference for Chinese children aged 3-17 years, compared the BP detection rate at baseline, at the first follow-up, and the average value of the last two BP readings. Fluctuations in the detection rate of elevated BP in children at different time-points were analyzed. Results: The detection rates of the three elevated BP measurements of 6-8-year-old children were 57.65%, 25.88% and 15.46%, respectively, and the detection rate was higher among boys than girls. The detection rate of baseline BP was higher than that of the first follow-up BP measurements and the average of the last two BP measurements(P<0.01). Given the agreement in the diagnosis of high SBP, high DBP, high BP at baseline, and the average of the last two follow-up BP measurements, elevated BP at baseline was the lowest among the three groups and SBP was higher than DBP. Conclusion Blood Pressure fluctuations might be caused by transient tension that was experienced during the baseline BP measurement and during the first of the three follow-ups. Therefore, the average value of last two BP measurements may better reflect the real BP level in children.

Objective: To examine the association between the visceral adiposity index (VAI) and nonalcoholic fatty liver disease (NAFLD) in the pediatric population in order to improve risk stratification and prevention systems for chronic liver disease. Methods: A total of 510 overweight/obese children aged 6-8 years old were enrolled from the child cohort which was designed to study puberty, obesity, and cardiovascular risk (PROC), and complete data from liver ultrasounds and the VAI were obtained. Used Spearman s rank correlation coefficient, Chi-square tests, and Logistic regression analyses to explore the association between the VAI and NAFLD. Results: The detection rates of NAFLD for boys and girls were 25.9% and 11.1%, respectively. VAI for normal group and the NAFLD group were 0.43(0.31, 0.61) and 0.61(0.44, 0.87) in boys, and 0.74(0.56, 1.07) and 1.08(0.67, 1.51) in girls, respectively. Spearman s correlation coefficient analysis showed that triglycerides(TG), VAI, and the third quintile VAI group were positively correlated with NAFLD in both boys and girls(r=0.19,0.26,0.29;0.16,0.16,1.18,P<0.05), and high-density lipoprotein-cholesterol (HDL-C) was negatively correlated with NAFLD in boys (r=-0.21, P<0.05). With advancing tertiles of VAI, the increasing trend in the NAFLD detection rate was statistically significant in boys and girls(Chi-square for trend were 21.77,7.66, P<0.01). The results of univariate and multivariable Logistic regression showed that, by taking the first tertile of VAI as a reference, the risk of NAFLD among boys was higher in the second tertile (cOR=2.59, 95%CI=1.15-5.86; aOR=2.33, 95%CI=1.01-5.36) and in the third tertile(cOR=5.73, 95%CI=2.62-12.53; aOR=4.87, 95%CI=2.15-11.03), where as the risk among girls was higher in the third tertile(cOR=4.43, 95%CI=1.40-14.00). Conclusion VAI is positively correlated with pediatric NAFLD. Higher tertiles of VAI were associated with an increased risk of NAFLD in overweight and obese children, which indicates that VAI can be used as an early predictor of NAFLD.

Objective: To investigate the nutritional status of the rural compulsory education students from "Rural Compulsory Education Students Nutrition Improvement Program"(hereinafter referred to "plan") in Ningxia, to provide a scientific basis for future targeted nutrition education and interventions. Methods: The survey was conducted in 27 732 students aged 6 to 15 years selected by stratified samplings in 7 counties of Ningxia. Results: In the 5 years of the "plan" implementation, trend in decreasing malnutrition rates across the 5 years(18.16%, 18.77%, 17.08%, 14.38%, 14.93%), with statistically significant difference(Chi-square for trend was 47.02, P<0.01). Overnutrition rate significantly increased(5.21%, 4.89%, 5.51%, 5.68%, 6.83%, Chi-square for trend was 6.66, P<0.01). Conclusion Improved nutritional status of rural primary and middle school students in Ningxia has been observed, Co-occurring of malnutrition in boys and overnutrition requires further attention.

Objective: To examine the vitamin A status of children and adolescents aged between 6-17 years old in Chongqing, and to analyze the influencing factors of vitamin A deficiency, providing a scientific basis for nutritional improvement measures. Methods: From 2016 to 2017, a multi-stage random sampling method was used to select approximately 1 508 children and adolescents aged between 6-17 years old from three rural and three urban locations in Chongqing. This study carried out a questionnaire survey and laboratory testing, and the statistical analysis was performed using SPSS version 25.0. Results: The mean vitamin A level was (1.45±0.42)μmol/L, while the prevalence of vitamin A deficiency and the subclinical deficiency rate were 0.46% and 13.46%, respectively. The binary Logistic regression analysis revealed that the following factors were associated with a lower risk of vitamin A deficiency:overweight and obese students(OR=0.51); students whose mothers had a high school education or above(OR=0.35, P=0.01); students from big cities; and higher quartile albumin levels (Q 3 and Q 4). Students who did not eat meat each day(OR=2.05), students aged 6-8 years old, and students with C-reactive protein in the third (OR=2.12) and fourth (OR=4.54) higher quartiles were at a higher risk of vitamin A deficiency. Conclusion The subclinical vitamin A deficiency rate was relatively high among children aged 6-17 years old in Chongqing. Measures including nutritional education, reasonable diets, and nutritionally fortified food or fortifiers should be used when necessary.

Objective: To explore the association between mothers reactions to adolescents exposure to intimate shots and pornography use of junior high school students, and to provide references for family communications on sexual topics in similar scenarios. Methods: A total of 1 760 students from grade 6 to 8 in three junior high schools in a certain district of Shanghai were selected by cluster sampling. Self-filled questionnaires on tablets were used to collect data. Results: The proportion of junior high school students who watched pornography was 26.36%(464), and that of boys (29.83%，270/905) was higher than of girls (22.69%，194/855). Most junior high school students believed that mothers reactions to adolescents exposure to intimate shots would be “taking the opportunity to educate teenagers not to do this” (30.54%) or “avoiding adolescents watching intimate shots” (42.24%). The results of multivariable analysis showed that comparing with junior high school students who believed that mothers would “watch together without making any comments ”, students who believed that mothers would “take the opportunity to educate teenagers not to do this”(OR=0.43, 95%CI=0.29-0.64) and “avoid adolescents watching intimate shots”(OR=0.56, 95%CI=0.39-0.80) were at lower risk of viewing pornography (P<0.01). Conclusion There is a significant correlation between junior high school students pornography use and mothers possible reactions to adolescents exposure to intimate shots. Family sex education and parental monitoring should be emphasized, and parents awareness of communicating sexual issues with adolescents should be strengthened.

Objective: To understand the status of family sex education and associated factors among preschoolers in Wuhu, providing scientific basis for child family sex education. Methods: From July to August 2020, random cluster sampling was used to select 481 children from 5 kindergartens in Wuhu. A questionnaire survey among parents of these preschoolers regarding family sex education status and its influencing factors. Results: A total of 285(59.25%) parents reported family sex education for children, and 196(40.75%) did not practice family sex education for their children. Multivariate Logistic regression analysis showed parental awareness of sex education content(OR=3.06, 95%CI=1.95-4.78), parental anxiety for child sexual assault (OR=1.82, 95%CI=1.11-2.99) were associated with higher rate of family sex education. Conclusion Family sex education among preschoolers in Wuhu should be further promoted. Sex education training towards parents might help improve children s family sex education.

Objective: Explored the characteristics of parental rearing styles, and its association with depressive symptoms and the self-directed learning ability among high school students during COVID-19 epidemic, while providing a basis for family intervention in the area of adolescent mental health and students learning abilities. Methods: A total of 2 893 high school students from the southern, central, and northern regions of Anhui Province were selected using a stratified-cluster sampling method in Feb. 2020. The online questionnaire survey regarding depressive symptoms, self-directed learning abilities, and rearing styles was administered using the smartphone application Questionnaire Star. Results: The prevalence rate of depressive symptoms was 38.9% among high school students during the COVID-19 outbreak. The parental rearing styles of high school students who reported depressive symptoms were characterized as follows:the scores of the parental emotional warmth factor, while relatively high scores of other factors, except the preferred factor. In addition, all of the factors showed statistically significant differences(P<0.01). The parental rearing styles of high school students with a weak self-directed learning ability were characterized as low scores in parental emotional warmth, parents prefer, and paternal over-protection(P<0.05). Ordinal logistic regression analysis revealed that the negative correlation between depressive symptoms, low self-learning ability and parents emotional warmth(father OR=0.95, mother OR=0.95) and father over involvement(OR=0.95), the positive correlation between depressive symptoms, low self-learning ability and father rejection(OR=1.07) and over protection(OR=1.06). Conclusion Depressive symptoms and the self-directed learning ability of high school students might be associated with paternal rearing styles, particularly in the case of emotional warmth.