Objective: To explore the associations of moderate to vigorous intensity physical activity (MVPA) and sedentary behavior (SB) among primary and secondary school students and their parents, so as to provide a scientific basis for formulating targeted physical activity promotion strategies for children and adolescents. Methods: From 2021 to 2022, basic information and 24 h movement behaviors of 2 484 pairs of students and their parents were collected from five primary and secondary schools in Haizhu District, Guangzhou City, with a convenient sampling combining with cluster sampling method. Component regression models were constructed to analyze the relationship between parental MVPA, SB and primary and secondary school students MVPA and SB, and a component isochronous substitution model was used to explore the effects of mutual substitution between parental MVPA, residual components (time use components other than SB during the 24 h period), and SB on the behavioral activities of MVPA and SB in primary and secondary school students. Results: Parental MVPA and SB of students in grade 1 to 3 were positively correlated with both students MVPA and SB ( β=0.06, 0.12, P <0.01). The component isochronous substitution model showed that substituting 10 and 20 minutes of MVPA for SB by parents in grade 1 to 3 was associated with an increase in MVPA of students, and substituting 10 and 20 minutes of residual ingredients for SB was associated with a decrease in SB of students, with mean changes of 0.8 (95% CI =0.4-1.2) and 1.4 (95% CI =0.7-2.2) and -1.4 (95% CI =-1.7 to -1.1) and -2.9 (95% CI =-3.4 to -2.3)( P <0.05). No statistically significant associations were observed between parents of students in grades 4 to 6 and 7 to 9 and students physical activity and sedentary behaviour ( P >0.05). Conclusions Parents of students in grades 1 to 3 increases MVPA and decrease SB are beneficial to increase MVPA and decrease SB of students. Parents could promote physical activity among primary and secondary school students, and the intervention gateway should be advanced, with the low grades as the optimal intervention period.

Objective: To explore the impact of sleep quality, experience of childhood maltreatment, and their interaction on depressive symptoms among middle school students, so as to provide the reference for early intervention of depressive symptoms among middle school students. Methods: From September to December 2023, a questionnaire survey was conducted among 1 231 students from two secondary schools in Harbin, Heilongjiang Province by a convenient sampling method. The survey included general demographic information, Childhood Trauma Questionnaire Short Form, Pittsburgh Sleep Quality Index and Short Version of Center for Epidemiological Studies Depression Scale. The Chi square test was used to analyze the differences in depressive symptom, sleep quality and childhood maltreatment among students with different demographic characteristics. Correlation analysis was conducted using Logistic regression, and interaction analysis was performed by both additive and multiplicative interaction models. Results: The detection rate of depressive symptoms among middle school students was 22.7%, and the rate for high school students (35.2%) was significantly higher than that for middle school students (17.0%) ( χ 2=50.35, P <0.01). The detection rates of depressive symptoms among middle school students with a history of childhood maltreatment and poor sleep quality were 45.8% and 44.0%, respectively. Multivariate Logistic regression analysis showed that compared to students without a history of childhood maltreatment, students with a history of childhood maltreatment had a higher risk of depressive symptoms ( OR =4.49，95% CI =3.31~ 6.09 , P <0.01);students with poor sleep quality had a higher risk of depressive symptoms than students with good sleep quality ( OR = 5.99，95% CI =4.37~8.22, P <0.01).The interaction results showed that the presence of childhood maltreatment and poor sleep quality had an additive interaction on the occurrence of depression in middle school students. Compared with students without childhood maltreatment and having good sleep quality, students with childhood maltreatment and poor sleep quality had a 22.49 times higher risk of developing depression ( OR =22.49，95% CI =14.22~35.59, P <0.01). Conclusion Depressive symptoms among middle school students are associated with childhood maltreatment and poor sleep quality, and there is an additive interaction between childhood maltreatment and poor sleep quality on the impact of depressive symptoms.

Objective: To explore the impact of family function intervention on mental health status of middle school students, so as to provide the reference for promoting adolescent mental health. Methods: From October 2023 to January 2024, 44 families from grade 2 of one junior high school were recruited. They were randomly divided into an intervention group ( n =21) and a control group ( n =23) using a simple random sampling method. Both groups of families participated in various daily school activities and learning, but the intervention group of families also participated in 10 online family function intervention courses. Family Assessment Device (FAD) and the Middle School Student Mental Health Scale (MSSMHS) were used as evaluation tools. Pearson correlation analysis was used to test the correlation between FAD total scores of middle school students and the total mean scores of MSSMHS, and repeated measures ANOVA was used to analyze FAD scores changes in various dimensions before and after intervention. Results: The total score of FAD in middle school students was positively correlated with the total average score of MSSMHS ( r= 0.44, P <0.01). Before intervention, there was no statistically significant difference in the FAD scores (intervention group: 143.19 ±16.05, control group:144.87±22.40) and MSSMHS total average scores (intervention group: 1.69±0.46, control group: 1.77 ±0.59) between the two groups ( t=0.28, 0.53, P >0.05). After intervention, the main effect of time, group, and time group interaction of the interventions on the FAD total scores between the intervention group and the control group were statistically significant ( F=11.87, 7.26, 11.04, P <0.05). Further simple effects analysis revealed that the post test FAD total score of the intervention group (121.71±16.01) decreased by 21.48 points compared to the pre test and was lower than the post test total score of the control group (144.47±17.71), with statistically significant differences ( t=4.68, 4.11, P <0.05). The main effect of the group on the total mean MSSMHS score between the intervention and control groups was statistically significant ( F=8.45, P <0.05), while the main effect of time was not statistically significant ( F=1.68, P >0.05). Further comparative analysis revealed that the post test total mean score of MSSMHS in the intervention group (1.34±0.23) was lower than that in the control group (1.85±0.52) ( t=3.48, P <0.01). Conclusion Family function intervention can improve the mental health status of middle school students, and relevant measures should be actively taken to promote adolescent mental health.

Objective: To explore the assocation of the family environment and depressive symptoms among primary and middle school students, so as to provide suggestions for further maximizing the utility of family environment in the growth of primary and secondary school students, as well as prevention and intervention of depressive symptoms among children and adolescents. Methods: From June to July 2024, through a multistage cluster random sampling method, 8 800 primary and middle school students aged 10 to 18 from 36 schools in 3 cities (Datong, Lvliang, Linfen) in Shanxi Province. A self designed questionnaire was used to conduct a family environment survey, including family socioeconomic conditions, family structure, family parenting behavior, family member health behavior, etc; and the depression symptoms of primary and secondary school students were investigated by Patient Health Questionnaire-9. The χ 2 test and binary Logistic regression to method were used to analyze the association of the family environment with depressive symptoms among primary and secondary school students, and to analyze gender and urban-rural heterogeneity in this association. Results: The detection rate of depressive symptoms among primary and middle school students was 46.7% ( n = 4 111 ). Among them, the detection rates of depressive symptoms for male and female students were 45.7% and 47.7% respectively, and the detection rates for rural and urban students were 48.0% and 44.9% respectively. The results of binary Logistic regression model showed that in the family environment, factors such as the father s education level (junior high school: OR =0.84), self assessed family socio economic status (average: OR =0.78, good: OR =0.80), parental support and understanding (yes: OR = 0.55 ), family atmosphere (harmonious: OR =0.66), living arrangement (living only with father or mother: OR =1.31, living with parents and grandparents: OR =1.19), and family rearing style (combining punishment and reward: OR =1.42, punishment only: OR =1.25) were related to depressive symptoms in primary and middle school students in Shanxi Province ( P <0.05). From the perspective of gender heterogeneity, the living arrangement (living only with father or mother: OR =1.67, others: OR =1.67) had a statistically significant association with depressive symptoms in male students ( P <0.05). From the perspective of urban rural heterogeneity, the living arrangement (living only with father or mother: OR =1.38) had a statistically significant association with depressive symptoms in rural primary and middle school students ( P <0.05). Conclusions The family environment has an important impact on depressive symptoms in primary and middle school students. Family functioning should be fully exerted to prevent depressive symptoms in primary and middle school students.

Objective: To explore the relationship between related factors of non-suicidal self-injury behavior (NSSI) among middle school students in Guizhou Province, so as to provide the evidence for preventing high risk behaviors in adolescents. Methods: A stratified cluster random sampling method was used to select 1 034 junior and senior middle school students from Zunyi City, Qiannan Prefecture and Tongren City in Guizhou Province from April to October in 2023. Questionnaire survey was conducted to collect information including Adolescent Self injury Scale and Family Assessment Device. The R 4.4.1 software was employed for network analysis visualization, centrality indicators, and result stability assessment. Results: The detection rate of NSSI behavior among middle school students in Guizhou province was 29.6%, with a detection rate of 25.5% for boys and 33.1% for girls, showing a statistically significant difference ( χ 2=7.07, P <0.05). There were statistically significant differences in scores of emotional communication, egoism, family rules, positive communication, problem solving, expression of positive emotions and management of negative emotions self-efficacy, and bullying victimization in various dimensions between middle school students with and without NSSI ( Z =-13.66 to -7.05, P <0.01). NSSI among middle school students was positively correlated with social/relational bullying, depression and anxiety, and there were relatively close connections in the network ( r =0.35, 0.43, 0.42, P <0.01). Centrality indicators showed that the highest in strength and closeness centrality were stress ( Z =1.29, 1.58), the highest in betweenness centrality was for emotional communication ( Z =1.91), and the highest in expected influence index was for physical bullying ( Z =1.44)( P < 0.05). Conclusions Stress, emotional communication and physical bullying have significant impacts in the network of factors related to NSSI. Social/relational bullying, depression and anxiety have strong direct correlations with NSSI behavior among middle school students.

Objective: To investigate the current status and trends of depressive symptoms among middle school and college students in Hunan Province, and to explore the primary related factors of depressive symptoms, so as to provide a scientific basis for strengthening mental health among students. Methods: A total of 279 382 students in Hunan Province were selected through a stratified cluster random sampling method from 2021 to 2023. National Survey Questionnaire on Common Diseases and Health Influencing Factors among Students was adopted for the survey, and the Center for Epidemiological Studies Depression Scale was used to assess their depressive symptoms. The χ 2 test and trend χ 2 test were used to analyze depressive symptoms prevalence and trends, and multivariable Logistic regression was used to analyze the related factors of depressive symptoms. Results: The prevalence of depressive symptoms among students in Hunan Province from 2021 to 2023 were 19.66%, 20.17% and 21.47%, respectively, showing an upward trend ( χ 2 trend =9.07, P <0.01). In addition, the results of the multivariable Logistic regression analysis showed that students with healthy diet ( OR=0.43, 95%CI =0.40-0.45), adequate sleep ( OR=0.88, 95%CI =0.86-0.90), and acceptable screen time ( OR=0.61, 95%CI =0.60-0.62) had lower risks in depressive symptoms detection, while students with smoking ( OR= 1.95, 95%CI =1.88-2.02), secondhand smoke exposure ( OR=1.33, 95%CI =1.30-1.36) and Internet addiction ( OR= 4.19 , 95%CI =4.05-4.34) had higher risks in depressive symptoms detection, with differences in the degree of association among different genders, educational stages and urban rural groups ( OR=0.40-6.04, Z =-12.69-11.98) ( P <0.05). Conclusions There is an increasing trend of depressive symptoms among middle school and college students in Hunan Province from 2021 to 2023.Targeted depression prevention measures should be taken for students with different demographic characteristics to promote their mental health.

Objective: To explore the association of physical activity and sugar sweetened beverage consumption with psychological sub health among middle school students in Bao an District, Shenzhen, so as to provide a reference for adolescent mental health promotion. Methods: A questionnaire survey was conducted in November 2024 by a stratified cluster random sampling method to select 6 926 junior and senior middle school students from 5 middle schools in Shenzhen. The questionnaire from Youth Risk Behavior Surveillance System was used to assess the consumption of sugar sweetened beverages, and physical activity Rating Scale was used to assess the level of physical activity, and Brief Instrument on Psychological Health of Youths was used to evaluate the psychological sub health status. The Chi -square test was used to analyze the differences in the detection rates of psychological sub health among different groups of middle school students, and a multivariate Logistic regression model was established to analyze the effects of physical activity and sugar sweetened beverage consumption and their combined effects on the psychological sub health of middle school students. Results: The detection rate of psychological sub health among middle school students in Bao an District, Shenzhen was 18.93%. Multivariate Logistic regression analysis showed that, after controlling for confounding factors such as gender, school stage, family residence, family economic status, parental literacy, academic stress and number of friends, lack of physical activity or excessive sugar sweetened beverage consumption were associated with increased risks of psychological sub health among middle school students ( OR =1.36, 1.45); and the highest risk of psychological sub health was found in middle school students who were lack of physical activity and excessive sugar sweetened beverage consumption ( OR =2.59) ( P <0.01). Further analysis by school stages showed that junior high school students with sufficient physical activity and excessive intake of sugary drinks ( ROR =2.10), lack of physical activity and excessive intake of sugary drinks ( ROR =2.31) were at higher risks of psychological sub health than senior high school students( P <0.05). Conclusions Insufficient physical activity and excessive sugar sweetened beverage consumption are closely associated with an increased risk of psychological sub health among middle school students. Effective interventions should be targeted to reduce the risk of psychological sub health problems among middle school students.

Objective: To explore the relationship of family function with sleep and externalizing problem behaviors of preschool children, so as to provide a guidance for externalizing problem prevention and intervention among preschool children. Methods: From October 2023 to January 2024, a convenience sampling method was used to select 5 138 preschool children from kindergartens in 8 districts of Wuhan City, Hubei Province. Parents completed the survey for Family Adaptability and Cohesion Scale, children s sleep habits and Child Behavior Checklist (CBCL). Spearman correlation analysis was used to examine the correlation of family function with scores of sleep quality and externalizing problem behaviors among preschool children. A mediation model analysis and bootstrap test were conducted to further investigate the mediating role of sleep quality between family function and externalizing problem behaviors. Mplus 8.7 software was used for latent profile analysis of family function. Results: The reported rates of poor sleep quality and externalizing problem behaviors among preschool children were 11.8% ( n =607), 20.0% ( n =1 026). The relevant analysis results showed that family function was negatively correlated with sleep quality and externalizing problem behaviors ( r = -0.20, -0.23), and sleep quality was positively correlated with externalizing problem behaviors ( r =0.27) ( P <0.01). The mediation effect test showed that family function negatively predicted externalizing problem behaviors ( β =-0.079) and sleep quality ( β = -0.075), while sleep quality positively predicted externalizing problem behaviors ( β =0.215) ( P <0.01). The latent profile analysis results showed that family function could be classified into 4 categories: high family function group (23.01%), upper middle family function group (44.65%), moderate family function group (26.24%) and low family function group (6.11%). Compared to high family function, the other three categories significantly positively predicted externalizing problem behaviors, and the mediating effects of sleep quality on different categories of family function were statistically significant [upper middle family function: mediation effect value was 0.022 (95% CI =0.004-0.041) and direct effect value was 0.329 (95% CI =0.263-0.396); middle family function: mediation effect value was 0.087 (95% CI =0.063-0.115) and direct effect value was 0.491 (95% CI =0.416-0.565); low family function: mediation effect value was 0.144 (95% CI =0.107-0.185) and direct effect 0.621 (95% CI =0.503-0.740)] ( P < 0.05 ). Conclusion Family function negatively predicts the externalizing problem behaviors of preschool children, and sleep quality plays a partial mediating role.

Objective: To evaluate and compare the accuracy of body mass index (BMI), waist circumference (WC), waistcorrected BMI (wBMI), and waist to height ratio (WHtR) in predicting hand grip strength (HGS) in high school girls, so as to provide the reference for evaluating their overall physical fitness and health status. Methods: From May to December in 2022, a total of 1 600 girls aged 15 to 18 years old were selected by cluster random sampling from 12 high schools in Xuzhou, Jiangsu Province. Measures of HGS, waist circumference, height and weight among high school girls were taken, and their BMI, wBMI and WHtR were calculated. Pearson correlation analysis and Logistic regression were used to analyze the association between BMI, wBMI, WC, WHtR and HGS Receiver operating characteristic (ROC) curves were constructed to evaluate the accuracy of different indicators in predicting HGS Results: Pearson correlation analysis showed that the BMI, wBMI, WHtR and HGS expression of high school girls were positively correlated ( r =0.31, 0.27, 0.32, 0.14, P < 0.01 ). Logistic regression analysis showed that BMI, WC and wBMI were correlated with HGS expression ( OR=2.00, 0.47, 1.22, P <0.05), while the association of WHtR and HGS expression had no statistical significance ( OR=0.51, P >0.05). The area under the curve (AUC) of BMI for predicting HGS expression in high school girls was the largest (AUC=0.65, 95% CI =0.61-0.69), followed by the AUC of wBMI for predicting HGS expression (AUC=0.65, 95% CI =0.57-0.66)( P <0.05). The most sensitivity was wBMI (71.5%), followed by BMI (69.4%), and the least sensitivity was WHtR (52.3%); and WC had the best specificity (61.1%), whereas wBMI had a relatively low specificity (52.5%). Conclusion For high school girls, BMI, WC and wBMI could predict the strenth of HGS expression, but BMI and wBMI have the highest accuracy and sensitivity, while wBMI has the lowest specificity in predicting the strenth of HGS.

Objective: To analyze the association between fine particulate matter (PM2.5) exposure in the air and dyslipidemia among primary school students, in order to provide the evidencebased support for the prevention and control of chronic diseases in children. Methods: The random sampling method was used to select 625 students from two primary schools in Anhui Province and Tianjin City from May to June 2024. Based on the home address, the annual average exposure levels of PM2.5 were obtained in 3 years before investigation, 2 years before investigation, and the past year before investigation. Fasting blood samples were collected for the detection of total cholesterol, triglycerides (TG), highdensity lipoprotein cholesterol and lowdensity lipoprotein cholesterol. Linear regression modeling was used to analyze the association between PM2.5 exposure and dyslipidemia among primary school students. Results: The rate of dyslipidemia among primary school students was 14.72% in the present study. The results of linear regression analysis showed that the TG increased by 0.019(95%CI=0.012-0.025)，0.023(95%CI=0.016-0.030) and 0.021(95%CI=0.014-0.027) mmol/L for every 1 μg/m3 increase of PM2.5 in the past year before investigation, 2 years before investigation and 3 years before investigation respectively (P<0.05). The results of binary Logisitic analysis showed that the risks of dyslipidemia in primary school students were positively correlated with PM2.5 mass concentration in the past year before investigation, 2 years before investigation, and 3 years before investigation [OR(95%CI)=1.06(1.02-1.11), 1.06(1.01-1.12), 1.06(1.01-1.11), P<0.05]. Conclusions PM2.5 exposure is associated with increased risk of dyslipidemia among primary school students. To protect the health of primary school students, effective measures should be taken to improve air quality.