Pediatric body mass index trajectories and the risk of hypertension among adolescents in China: a retrospective cohort study.

BACKGROUND: The impact of pediatric body mass index (BMI) trajectories on the risk of adolescent hypertension (HTN) determined by three separate visits remains unclear. This longitudinal study aims to identify potential pediatric sex-specific BMI trajectories and to assess their associations with HTN and HTN subtypes. METHODS: Based on the Health Promotion Program for Children and Adolescents (HPPCA) in Suzhou, China, a total of 24,426 participants who had initial normal blood pressure (BP) and had at least four BMI measurements during 2012-2020 were included. HTN was defined as simultaneously having three separate visits of elevated BP in 2020. Latent class growth models were used to explore sex-specific BMI trajectories, whose associations with HTN and HTN subtypes were further examined by logistic regression. RESULTS: The incidence of HTN determined through three separate visits was 3.34%. Four trajectories were identified for both sexes: low BMI increasing, medium BMI increasing, high BMI increasing, and highest BMI increasing. Compared to the medium BMI increasing group, the odds ratio (95% confidential interval) for developing adolescent HTN of the low, high, and highest BMI increasing groups among boys were 0.54 (0.39, 0.75), 1.90 (1.44, 2.51), and 2.89 (1.90, 4.39), respectively; and the corresponding values for girls were 0.66 (0.48, 0.90), 2.30 (1.72, 3.09), and 4.71 (3.06, 7.26). Similar gradually elevated associations between different trajectories with isolated systolic hypertension, systolic and diastolic hypertension were observed. CONCLUSION: Current results emphasized the adverse effects of stable high BMI on HTN and the benefits of maintaining normal weight throughout childhood.

Comparisons of tri-ponderal mass index and body mass index in discriminating hypertension at three separate visits in adolescents: A retrospective cohort study.

Objective: To estimate whether the new obesity indicator tri-ponderal mass index (TMI) has a better capacity to predict adolescent hypertension (HTN) and HTN subtypes at three separate blood pressure (BP) visits than the conventionally used body mass index (BMI). Methods: A total of 36,950 adolescents who had initial normal BP from 2012 to 2019 were included in Suzhou, China. HTN was defined as having three separate visits of elevated BP in 2020. The area under the receiver-operating characteristic curve (AUC), false-positive rate, false-negative rate, total misclassification rates, net reclassification improvement (NRI), and integrated discrimination improvement were calculated to compare the discriminative ability of HTN between BMI and TMI. Results: TMI had better predictive abilities than BMI among all of the participants when predicting HTN (difference in AUC = 0.019, 95% CI = 0.007-0.031; NRI = 0.067, 95% CI = 0.008-0.127) and isolated systolic hypertension (difference in AUC = 0.021, 95% CI = 0.005-0.036; NRI = 0.106, 95% CI = 0.029-0.183). The difference in prediction abilities between BMI and TMI was more obvious in the subgroup of age ≥16. Also, TMI outperformed BMI in predicting adolescent HTN in girls but not in boys. Conclusion: Compared with BMI, TMI may have a better predictive capacity for HTN, particularly in girls and older adolescents. TMI has the potential to be used as an effective predictor for HTN in clinic practice. Further studies are needed to verify the utility of TMI.

Prevalence of hypertension and related risk factors among children and adolescents at three separate visits: A large school-based study in China.

Objective: We aimed to demonstrate characteristics of hypertension at three separate visits and its risk factors among children and adolescents based on a large school-based study in China. Materials and methods: Based on a large-scale ongoing monitoring program conducted in Suzhou, China, 59,679 children and adolescents aged 7-17 years from 60 public schools were enrolled during 2020 to 2021. Height, weight, and blood pressure (BP) were measured. Additional BP would be measured for hypertensive students at least 2 weeks later. Confirmed hypertension was defined as simultaneously BP meeting above or equal to 95th percentile for age, sex, and height at three separate visits. Odds ratio (ORs), and 95% CIs were calculated by logistic regression to identify risk factors for hypertension. Results: Prevalence of hypertension at three separate visits were 20.4, 6.3, and 3.1%, respectively. Prevalence of confirmed isolated systolic hypertension, isolated diastolic hypertension, and systolic and diastolic hypertension were 1.9, 0.3, and 0.9%, respectively. Hypertension prevalence for stages 1 and 2 were 2.6 and 0.6%. Different hypertension prevalence were found among various age and gender groups. Boys [OR, 1.137 (95% CI, 1.033-1.251)], high age [OR, 3.326 (95% CI, 2.950-3.751)], urban residents [OR, 1.579 (95% CI, 1.417-1.760)], high-socioeconomic status [OR, 1.156 (95% CI, 1.039-1.286)] and body mass index category including overweight [1.883 (95% CI, 1.665-2.129)], obesity [4.049 (95% CI, 3.625-4.523)], and thinness [OR, 0.457 (95% CI, 0.306-0.683)] were associated with confirmed hypertension. Conclusion: A single BP measurement would overestimate hypertension prevalence, about 3% Chinese children were hypertensive, early, and effective intervention around risk factors for hypertension should be taken.

Body mass index changes among children and adolescents in Suzhou before and after COVID 19 outbreak / 中国学校卫生

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.

Teaching environment of primary middle and high schools in Suzhou during 2019 / 中国学校卫生

Objective@#To analyze the teaching environment of primary, middle and high schools in Suzhou, and to explore the relevance of students’ myopia with teaching environment, as well as the key problems in teaching environment.@*Methods@#1 253 classrooms in 204 schools rom 10 districts and counties in Suzhou were selected by proportionate stratified sampling. The qualified rate of each indices was described and the teaching environment by county, learning stage were compared by using chi-squared test. The Spearman test is used to explore correlations between myopia with monitoring indicators.@*Results@#The qualified rate of the distance from lamp to table was the highest (98.56%), while matching rate of student desk and chair was the lowest(0.96%). Minimum lamp table spacing, blackboard average illumination, reflectance from blackboard wall, classroom per capita area, classroom microclimate differed significantly in urban and rural (P<0.05); daylighting coefficient, reflectance from walls, average illumination of desktop and blackboard, classroom per capita area, and microclimate indicator were statistically different by learning stages(r=0.42,P<0.05). Prevalence of myopia correlated with the index of lighting.@*Conclusion@#Qualified desks and matched chairs, as well as the daylighting design in classroom should receive more attention in Suzhou. The findings lend support to identification of key health priorities and formulation of the localized health practice for health administrations.

Comparison of high blood pressure among children and adolescents in Suzhou based on different references / 中国学校卫生

Objective@#The current study aimed to determine the prevalence of high blood pressure (HBP) among children and adolescents aged 7-17 years in Suzhou by using different references, and to provide a reference for the application of standard of blood pressure among children.@*Methods@#Data of 6 972 children and adolescents aged 7 to 17 years were collected by stratified cluster random sampling method to determine the prevalence of HBP based on 2017 AAP Guidelines for Childhood Hygertension(America 2017), National Blood Pressure Reference for Chinese Han Children based on Chinese National Survey on Students’ Constitution and Health in 2010 (Ma 2017), blood pressure guidelines based on their investigation in mainland children and adolescents (Mi 2017) and blood pressure guidelines based on data from the China Health and Nutrition Survey during the year of 1999-2009 (CHNS 2013).@*Results@#Referred to Ma 2017 reference, the prevalence of HBP was highest with 12.7%, followed by America 2017 with 16.3%, Mi 2017 with 17.4%, and CHNS2013 with 25.5%. In boys, HBP prevalence based on America 2017 was close to that using Mi 2017 among children younger than 13 years old, and was close to that using Ma 2017 among those≥14 years old. In girls, HBP prevalence based on America 2017 was close to that using Mi 2017 among those≤12 years old, and was close to that using Ma 2017 among those ≥13 years old. Compared with America 2017 reference, kappa value based on Mi 2017 was better than Ma 2017 in boys(0.81, 0.77), opposite result was found in girls(0.86, 0.85). Kappa value were the lowest based on CHNS 2013.@*Conclusion@#The prevalence of HBP among children in Suzhou achieve a high level. Ma 2017, Mi 2017, and CHNS2013 references show different advantages among various gender and age groups.