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.