Objective: To investigate the prevalence of hypertension among primary and middle school students living in Suzhou City, Jiangsu Province, so as to provide insights into comprehensive hypertension control among children and adolescents. Methods: Primary and middle school students at ages of 7 to 17 years were recruited for a questionnaire survey in Suzhou City using the stratified cluster random sampling method from September to December, 2020, and the height and body weight were measured. Blood pressure was measured at three separate clinic visits according to the national criteria Reference of Screening for Elevated Blood Pressure among Children and Adolescents Aged 7-18 Years ( WS/T 610-2018 ), and the detection of elevated blood pressure was estimated at three separate visits. In addition, factors affecting elevated blood pressure were identified. Results: A total of 3 713 students were enrolled, including 1 924 boys ( 51.82% ) and 1 789 girls ( 48.18% ). The detection of elevated blood pressure was 13.63%, 5.36%, and 3.37% at three separate visits, respectively, and the prevalence of hypertension ( elevated blood pressure at all three visits ) was 3.37%. The detection rates of elevated blood pressure were all higher at three visits ( 16.90%, 8.40%, and 5.26% ) among students at ages of 12 to 17 years than among students at ages of 7 to 11 years ( 9.65%, 1.67%, and 1.07%, P<0.05 ). The detection of elevated blood pressure was significantly higher in boys ( 15.23% ) than in girls (11.91%) at the first visit ( P<0.05 ), while no significant differences were seen at the second or third visit ( P>0.05 ). In addition, higher detection rates of elevated blood pressure were seen in obese ( 27.62%, 11.51%, and 7.06% ) and overweight students ( 17.45%, 6.95%, and 4.85% ) than in students with normal weight ( 9.44%, 3.54%, and 2.15% ) at all three visits, and greater detection rates of elevated blood pressure were found in obese students than in overweight students at the first and second visits ( P<0.017 ). Conclusions The prevalence of hypertension was 3.37% based on three separate visits among primary and middle school students in Suzhou City. Measurement of blood pressure at three separate visits within different days is effective to reduce the false positive rate of hypertension and decrease misdiagnosis among children and adolescents.

Objective: To explore body mass index (BMI) changes among children and adolescents in Suzhou before and after COVID-19 outbreak, and to provide a reference for improving physical health of children and adolescents. Methods: A total of 569 children and adolescents who had complete BMI information in 2019 were enrolled through stratified cluster sampling from June to July, 2020. Questionnaire survey was conducted, and height and weight were measured to calculate BMI and BMI Z scores. Results: After the epidemic, overweight/obesity rate were 32.0%, compared to 31.6% before the epidemic(χ 2=0.07, P>0.05). Difference of BMI Z scores before (0.37±1.28) and after (0.38±1.27) the epidemic did not show statistically significant (t=-0.28, P>0.05), No significant changes in BMI Z score were found before and affer COVID-19 outbreak similar results were observed (P>0.05), BMI Z scores after the epidemic (0.45±1.32) was higher than it before the epidemic (0.37±1.35) among primary school group (t=2.57, P=0.01), while BMI Z scores after the epidemic (0.27±1.17) was lower than it before the epidemic (0.39±1.18) among middle school group (t=-4.29, P<0.01). Proportion of sweet food consumption and outdoor activities was statistically different before and after the epidemic(P>0.05), proportion of sugar-sweetened beverages consumption and fried food intake were statistically different before and after the epidemic (P<0.05), sleep time after the epidemic (8.52±1.83)h was higher than it before the epidemic (8.05±1.70)h (t=4.96, P<0.05). Conclusion Before and after COVID-19 outbreak, BMI and overweight/obesity rates are significantly different among children and adolescents in Suzhou, and there is a slight difference in different studying phases.

Objective: To understand the trend of eye use behavior of students in Suzhou, and to provide basis for comprehensive prevention and control of myopia. Methods: Stratified cluster random sampling was used to recruit students from grades 4 to 12 in Suzhou from 2018 to 2021. The students general information, eye use behavior, outdoor activities and sleep status were collected through a standardized questionnaire to compare eye use behaviors of students among various groups. Results: The detection rates of students who watched TV or used computer more than 1 h/d decreased from 2018 to 2021( χ 2 trend =192.25, 95.39, P <0.05), and boys who spend more than 1 h/d on watching TV and using computer accounted for 26.4% and 19.2%, and girls accounted for 21.1 % and 12.8%, respectively in 2021. The proportion of students watching mobile electronic devices≥1 h/d decreased ( χ 2 trend =314.85, P <0.05), and the boys proportion was less than girls with 29.2% and 30.3% respectively, and each grade declined except for vocational high schools. The proportion of students with average reading and writing time after school above 2 h/d had decreased except for vocational school students. In 2021, the proportions of four school periods(primary school, middle school, high school and vocational school) were 22.1%, 47.7%, 65.1% and 11.6% respectively. The proportions of students with good eye habits such as reading with desk lamp and roof lamp, watching computer screen and TV with a safe distance, using eyes at close range for less than 1 h/d and taking a rest had increased ( χ 2 trend =34.19, 62.21, 47.25, 457.50, P ＜0.05), reaching up to 72.2%, 72.3%, 78.6 % and 67.8% respectively in 2021. The proportion of students spending more than 2 h/d on outdoor activities increased ( 27.1 % in 2018 and 30.7% in 2021, χ 2 trend =5.17, P ＜0.05), but only in primary school students, and the rates of boys were higher than girls . There was no improvement in sleep deprivation. The girls who were lack of sleep girls were more than boys, and the proportion of senior high school was higher than that of junior middle school and primary school. Conclusion The eye use behaviors of primary and middle school students have improved significantly from 2018 to 2021. However, the problems including insufficient sleep and less outdoor activities still exist. Health education in students aiming at eye use behavior improvement should be strengthened.

Objective To explore the ability of waist circumference (WC) to predict hypertension risk in overweight and non-overweight middle school students in Suzhou. Methods The height, weight，WC and blood pressure values of 963 students from 8 middle schools in Suzhou were collected by a combination of questionnaire survey and physical examination. Logistic regression analysis was applied to explore the correlation between WC and high blood pressure in middle school students. Results Logistic regression analysis showed that before and after adjusting for confounding factors, for every 1 cm change in WC, the risk of high blood pressure increased to 1.08 (1.03-1.14) and 1.07 (1.02-1.13) for non-overweight students, and 1.05 (1.02-1.09) and 1.05 (1.01-1.08) for overweight students, respectively. Conclusion There was a positive correlation between WC and high blood pressure in both non-overweight and overweight middle school students in Suzhou. The risk of high blood pressure was higher for non-overweight students than overweight students for every 1 cm WC change. Targeted intervention measures should be taken to reduce the prevalence rates of hypertension for middle school students.