Blood pressure and obesity among adolescents: a school-based population study in China

The ongoing impact of obesity on childhood hypertension

Obesity rates among children have been steadily rising over the past several decades. This epidemic has been accompanied by an increase in the prevalence of childhood hypertension, with children in low- and middle-income countries being affected to the same extent as children in high-income countries. This review will examine the trends in childhood blood pressure and the relationship between excess body weight and the development of hypertension. In addition, distinct mechanisms of obesity-related hypertension will be discussed. There will be an emphasis on recent studies conducted since the publication of new guidelines by the American Academy of Pediatrics in 2017 which resulted in the adoption of lower normative blood pressure cutoffs. The overall intent of this review is to provide the reader with an understanding of the ongoing impact, and complexities, of obesity-related hypertension.

Prevalence of hypertension and its associations with body composition across Chinese and American children and adolescents

BACKGROUND

The age of onset of hypertension (HTN) is decreasing, and obesity is a significant risk factor. The prevalence and racial disparities in pediatric HTN and the association between body composition and blood pressure are insufficiently studied. This study aimed to evaluate the prevalence of HTN in Chinese and American children and adolescents and to assess the relationship between various body composition indices and HTN.

METHODS

Seven thousand, five hundred and seventy-three Chinese and 6239 American children and adolescents aged 8-18 years from the 2013-2015 China Child and Adolescent Cardiovascular Health study and the 2011-2018 National Health and Nutrition Examination Surveys were analyzed. Blood pressure and body composition (fat and muscle) were measured by trained staff. The crude prevalence and age-standardized prevalence rate (ASPR) of primary HTN and its subtypes [isolated systolic hypertension (ISH) and isolated diastolic hypertension (IDH)] were calculated based on 2017 American Academy of Pediatrics guidelines. Multivariable-adjusted linear regression coefficients and odds ratios (ORs) were calculated to assess the associations of body composition indicators with HTN, ISH and IDH.

RESULTS

The ASPR of HTN was 18.5% in China (CN) and 4.6% in the United States (US), whereas the obesity prevalence was 7.4% and 18.6%, and the population attributable risk of HTN caused by overweight and obesity was higher in the US than in CN. Increased fat mass, muscle mass and body fat percentage mass were associated with a higher risk of HTN in both countries. The percent of muscle body mass had a protective effect on HTN and ISH in both countries [HTN (CN: OR = 0.83, 95% CI = 0.78-0.88; US: OR = 0.72, 95% CI = 0.64-0.81); ISH (CN: OR = 0.87, 95% CI = 0.80-0.94; US: OR = 0.71, 95% CI = 0.62-0.81)], and the protective effect was more common among children and adolescents with high levels of physical activity.

CONCLUSIONS

The burden of HTN in Chinese children and adolescents was substantial and much greater than that in the US, and the contribution of obesity to HTN was higher in the US than in CN. Augmenting the proportion of muscle mass in body composition has a protective effect against HTN in both populations. Optimizing body composition positively influences blood pressure in children and adolescents, particularly those with high-level physical activity. Video abstract (MP4 149982 KB).

Environments affect blood pressure in toddlers: The Japan Environment and Children's Study

BACKGROUND

The primary objective of this study was to examine risk factors for toddler's hypertension.

METHODS

Subjects of this study were children and parents participating in a national birth cohort study in Japan, the Japan Environment and Children's Study. We measured the children's blood pressure (BP) at 2 and 4 years old. We obtained children's and parents' backgrounds from the questionnaire. We investigated the factors that affect BP elevation.

RESULTS

Within 4988 participants, the mean systolic BP at 2 years old was 91.2 mmHg for boys and 90.0 mmHg for girls. The mean systolic BP at 4 years old was 93.8 mmHg for boys and 93.1 mmHg for girls. Parental smoking was associated with elevated values of BP at 2 and 4 years old. Obesity, gestational hypertension, and parental lower education were associated with elevated values of BP at 4 years old. Hypertensive group had a significantly higher obesity rate. The mother's lower education and parental smoking were involved in hypertensive groups.

CONCLUSION

Parental smoking had a significant effect on BP even in early toddlers. We emphasize the importance of avoiding second-hand smoking from early infancy to prevent future lifestyle-related illnesses including hypertension.

IMPACT

The mean systolic BP at 2 years old was 91.2 mmHg for boys and 90.0 mmHg for girls. The mean systolic BP at 4 years old was 93.8 mmHg for boys and 93.1 mmHg for girls. Obesity, parental smoking, and lower education were associated with hypertension at 4 years old. Parental smoking was associated with hypertension at 2 and 4 years old. We emphasize the importance of avoiding second-hand smoking from early infancy.

Trends of obesity and overweight among children and adolescents in China

BACKGROUND

Recent decades have shown a rapid increase in the prevalence of overweight and obesity among Chinese children based on several national surveys. Restrictions due to the coronavirus disease 2019 outbreak have worsened its epidemiology. This review updates the trends in the prevalence of overweight and obesity among Chinese children and adolescents and analyzes the underlying reasons to provide evidence for better policy making.

METHODS

Studies published in English and Chinese were retrieved from PubMed, Google Scholar, China National Knowledge Infrastructure and Wanfang.

RESULTS

The prevalence of overweight and obesity has been increasing for decades and varies with age, sex and geography but is more pronounced in primary school students. The increase in obesity in boys appeared to be slower, whereas that in girls showed a declining trend. The northern areas of China have persistently maintained the highest levels of obesity with a stable trend in recent years. Meanwhile, the prevalence in eastern regions has dramatically increased. Notably, the overall prevalence of obesity in children has shown a stabilizing trend in recent years. However, the occurrence of obesity-related metabolic diseases increased. The effect of migrants floating into east-coast cities should not be neglected.

CONCLUSIONS

The high prevalence of overweight and obesity among Chinese children and adolescents persists but with varying patterns. Obesity-related metabolic diseases occur more frequently despite a stable trend of obesity. Multiple factors are responsible for the changing prevalence. Thus, comprehensive and flexible policies are needed to effectively manage and prevent the burden of obesity and its related complications.

Nutrition, Body Composition, and Blood Pressure in Children and Adolescents from the Korea National Health and Nutrition Examination Survey

We aimed to investigate the association between nutrition and blood pressure and the role that body composition plays in this relationship. Korea National Health and Nutrition Examination Survey data from the years 2008-2020 were reviewed. A total of 11,234 subjects (5974 boys and 5260 girls) aged 10-18 years of age were selected. We analyzed the correlation between nutrition (intakes of energy, protein, fat, carbohydrate, sodium, saturated fatty acid (SFA), unsaturated fatty acid (USFA), and dietary fiber (DF)) and body composition (height, weight, waist circumference (WC), body mass index (BMI), and waist to height ratio (WHtR)), and performed multiple regression analysis to find the independent correlation between body composition and blood pressure (BP). We then compared the correlation between nutrition and BP, with or without adjustment for body composition. The intakes of energy, protein, fat, carbohydrate, sodium, and USFA had positive associations with height, weight, WC, and BMI. Systolic BP (SBP) and diastolic BP (DBP) were independently positively correlated with height and BMI. The intakes of energy, protein, fat, carbohydrate, sodium, and SFA had positive correlations with SBP and DBP, which disappeared when additionally adjusted for BMI and height. In conclusion, nutrition seems to affect BP via height and BMI in Korean children and adolescents.

High Prevalence of Cardiometabolic Comorbidities Among Children and Adolescents With Severe Obesity From a Large Metropolitan Centre (Hangzhou, China)

Objective

This study aimed to describe the clinical characteristics of children and adolescents with obesity, and the prevalence of cardiometabolic comorbidities over 10 years in this population from a large metropolitan centre in China.

Methods

This was a cross-sectional study (2008-2017) of patients aged <18 years with obesity [body mass index (BMI) ≥ 95th percentile for age and sex] enrolled at the Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine (Hangzhou, Zhejiang Province). Clinical assessments included anthropometry, blood pressure, liver ultrasound, lipid profile, oral glucose tolerance test, and uric acid. For examination of outcomes, our study cohort was stratified by sex and age bands (<10 vs. ≥10 years), with the study period also split into two strata (2008-2012 and 2013-2017).

Results

A total of 2,916 patients (1,954 boys and 962 girls) were assessed at a mean age of 10.5 years. Patients almost invariably presented severe obesity (median BMI SDS = 2.98; Q1 = 2.60, Q3 = 3.39). Obesity-related comorbidities were common among boys and girls, including type 2 diabetes mellitus (2.6% and 3.6%, respectively), abnormal glycaemia (33.6% and 35.5%, respectively), hypertension (33.9% and 32.0%, respectively), dyslipidaemia (35.2% and 39.6%, respectively), hyperuricaemia (16.2% and 8.3%, respectively), acanthosis nigricans (71.9% and 64.0%, respectively), abnormal liver function (66.9% and 47.0%, respectively), and non-alcoholic fatty liver disease (NAFLD) (63.8% and 45.1%, respectively); 38.7% of boys and 44.4% of girls aged ≥10 years had metabolic syndrome. Notably, the incidence of many cardiometabolic comorbidities was in 2013-2017 compared to 2008-2012. For example, rates of hypertension among boys aged <10 years and aged ≥10 years rose from 28.4% and 26.5% to 48.0% and 35.8%, respectively, and in girls from 20.3% and 20.8% to 41.7% and 39.6%, respectively. In 2013-2017, 9.5% of girls in the older group had metabolic syndrome compared to 2.2% in 2008-2013.

Conclusions

We observed a high incidence of obesity-related cardiometabolic comorbidities among Chinese children and adolescents with severe obesity over 10 years. It was particularly concerning that rates of several comorbidities rose markedly over the study period, highlighting the need to address the obesity epidemic early in life (in China and elsewhere) to prevent the development of obesity-related comorbidities and, subsequently, of overt disease.

Impact of Weight Reduction on Thyroid Function and Nonalcoholic Fatty Liver among Egyptian Adolescents with Obesity

BACKGROUND

The prevalence of childhood obesity has been increasing worldwide. This may explain the emergence of nonalcoholic fatty liver as the leading cause of liver disease. Several previous studies have addressed the association between thyroid function and nonalcoholic fatty liver disease.

OBJECTIVES

To study the impact of weight reduction through lifestyle modifications in adolescents with obesity.

METHODS

A prospective cohort study was done on 61 adolescents with obesity. Patients were evaluated at the first visit by the full history, clinical examination, and investigations (thyroid profile, lipid profile, liver function tests, HbA1c, and liver ultrasonography) as basal information. The intervention program included a dietary program, increasing physical activity, and decreasing sedentary activity. A postintervention evaluation was done at the end of six months which included anthropometric measures, laboratory results, and ultrasonographic estimation.

RESULTS

It was shown that the mean BMI of the participants had significantly decreased after lifestyle modification from (32.05 ± 3.36 kg/m2) to (28.1 ± 2.77 kg/m2) (P < 0.001). It also showed that the percentage of studied adolescents with elevated TSH decreased from 47.5% to 19.7% after the weight reduction program. Improvement was also achieved in the lipid profile and liver functions. The percentage of studied adolescents with ultrasound appearance of NAFLD decreased from 31.1% to 26.2% after weight reduction.

CONCLUSIONS

Lifestyle modification positively influences the metabolic derangement in obesity without medical treatment. ΔTSH is a significant predictor of the change in BMI z-score. It is also possible that hepatic steatosis affects thyroid function rather than the other way around.

Study of Cardiovascular Risks in Adolescents (ERICA): factors associated with work in adolescence

This study aimed to verify the association between work and sociodemographic factors, health behaviors, and cardiovascular risk in Brazilian adolescents. Data from the Study of Cardiovascular Risks in Adolescents (ERICA) were analyzed, with a sample of 37,815 adolescents aged 12-17 years and morning shift students. Considering complex sampling, crude and adjusted Prevalence Ratios (PR) were calculated with interval estimates for variables by Poisson multiple regression model with robust variance estimate. The sociodemographic factors associated with work among Brazilian adolescents were male gender (PR 1.34), aged 15-17 years, with maternal schooling up to elementary school (PR 1.26), public school students (PR 1.63), and from the rural area (PR 1.90). Regarding lifestyle habits and social behavior, the association was significant in physically active (PR 1.19) and alcohol-consuming students (PR 1.35). In conclusion, work among Brazilian adolescent morning shift students is still strongly linked to social issues. Work was associated with alcohol consumption, and there was no association with metabolic markers.

Elevated blood pressure and its relationship with bodyweight and anthropometric measurements among 8-11-year-old Indonesian school children

Objective: Increased prevalence of elevated blood pressure in children and adolescents was associated with increased body weight and measures. Also, prevalence of elevated blood pressure varies between countries. This study is to investigate the prevalence of elevated blood pressure in Indonesian children and its relationship with bodyweight and anthropometric measures. Methods: This cross-sectional study involved 1010 elementary students aged 8 - 12 years (479 girls, 531 boys). The anthropometric measures and blood pressure were assessed. Elevated blood pressure (EBP) was determined if at the 90^th percentile or above for gender, age, and height. Independent t-test, Chi-square, Pearson correlation, and multivariate logistic regression were applied. Significance was determined at p<0.05. Results: Overall prevalence of EBP was 28.8% (35.9% in girls, 22.4% in boys). BMI, waist circumference (WC), waist to height ratio (WHtR), and abdominal skinfold had significant correlation with EBP. Elevated BP was higher in overweight and obesity than in normoweight (60.5% vs 39.5%, p=0.00). In girls, the OR of EBP for overweight and obesity were 2.33 (95% CI 1.40-3.87, p=0.03) and 3.44 (95% CI 1.98-5.99, p=0.00) whereas in boys were 4.26 (95% CI 2.20-8.28, p=0.00) and 8.82 (95% CI 5.10-15.38, p=0.00). Conclusions: Prevalence of EBP in Indonesian school children aged 8 - 11 years was higher and more prevalent in overweight/ obesity and in girls. Anthropometric measures were correlated with EBP.

Central obesity and hypertension among rural adults of Paschim Medinipur, West Bengal, India

Obesity is generally classified into generalized obesity (BMI ≥30 kg/m2) and abdominal or central obesity (WC ≥90 cm for men and WC ≥80 cm for women) based on World Health Organization recommendation for Asians. Hypertension is one of the most common obesity-related complications, and about 30% of hypertensive individuals can be classified as being obese. The present study aimed to investigate the effect of different age groups (years) on the anthropometric and derived variables. It determined the correlation between anthropometric and derived variables and also estimated the frequency of central obesity and hypertension. Finally, it investigated the relationship between central obesity and blood pressure among rural Bengalee adults of Dirghagram village of Ghatal Block, Paschim Medinipur, West Bengal, India. The present cross-sectional study was undertaken among 310 rural adults (154 males; 156 females) aged over 18 years. Our study was carried out during March, 2017. Height (cm), weight (kg), waist circumference (cm), hip circumference (cm) and blood pressure (systolic and diastolic) were measured using standard procedures. One way ANOVA analysis on most of the anthropometric and derived variables showed a statistically significant increase from younger to older age group in both sexes (p<0.001;p<0.01; p<0.05). In addition to that, more females had central obesity using waist circumference (55.8% vs. 19.5%), waist hip ratio (87.2% vs. 35.7%), waist height ratio (73.7% vs. 44.2%), and conicity index (87.2% vs. 57.8%) criteria, and hypertension (52.5% vs. 27.3%). The prevalence of central obesity was much higher in case of hypertensive individuals. Therefore, the present study showed a high prevalence of central obesity among the rural adults of Dirghagram village. Furthermore, central obesity contributed in increasing hypertension among the villagers.

Smartphone addiction may be associated with adolescent hypertension: a cross-sectional study among junior school students in China

BACKGROUND

Hypertension in children and adolescents is on the rise worldwide, especially in China. The prevalence of hypertension is related to many factors, such as obesity. In the era of smart phones, it is important to study the negative health effects of mobile phones on blood pressure. The purpose of this study was to investigate the prevalence of hypertension and its association with smartphone addiction among junior school students in China.

METHODS

A school-based cross-sectional study was conducted, including total 2639 junior school students (1218 boys and 1421 girls), aged 12-15 years old (13.18 ± 0.93 years), enrolled in the study by random cluster sampling. Height, weight, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured following standard protocols, and the body mass index (BMI) was calculated. Overweight/obesity and hypertension were defined according to sex- and age-specific Chinese children reference data. The Smartphone Addiction Scale short version (SAS-SV) and the Pittsburgh Sleep Quality Index (PSQI) were used to assess smartphone addiction and sleep quality among the students, respectively. Multivariate logistic regression models were used to seek associations between smartphone addiction and hypertension.

RESULTS

The prevalence of hypertension and smartphone addiction among participants were 16.2% (13.1% for females and 18.9% for males) and 22.8% (22.3% for females and 23.2% for males), respectively. Obesity (OR = 4.028, 95% CI: 2.829-5.735), poor sleep quality (OR = 4.243, 95% CI: 2.429-7.411), smartphone addiction (OR = 2.205, 95% CI: 1.273-3.820) were significantly and independently associated with hypertension.

CONCLUSIONS

Among the junior school students surveyed in China, the prevalence of hypertension was high, which was related to obesity, poor sleep quality and smartphone addiction. These results suggested that smartphone addiction may be a new risk factor for high blood pressure in adolescents.

U-shaped relationship between birth weight and childhood blood pressure in China

Background

The relationship between birth weight and blood pressure has not been well explored in Chinese children and adolescents. The aim of this study was to investigate the relationship between birth weight and childhood blood pressure in China.

Methods

A total of 15324 children and adolescents (7919 boys and 7405 girls) aged 7–17 years were stratified into six birth weight groups. Analysis of covariance and binary logistic regression were used to analyse the relationship between birth weight and blood pressure while controlling for potential confounding factors, including age, gestational age, season of birth and area of residence.

Results

The group with birth weights from 2500 to 2999 g had the lowest prevalence of hypertension (8.9%). Lower birth weight children (< 2000 g) had significantly higher systolic blood pressure (SBP) (106.00 ± 0.72, P = 0.017), and children with heavier birth weights also had higher SBP (3500–3999 g, 105.13 ± 0.17, P < .001; ≥ 4000 g, 105.96 ± 0.27, P < .001). No significant relationship was found between birth weight and diastolic blood pressure (DBP). The overall rate of hypertension was 10.8% (12.1% in boys and 9.4% in girls). The median weight group (2500–2999 g) had the lowest rate of hypertension (8.9%). Compared with children in the median weight group, children with lower birth weight had a higher prevalence of hypertension (< 2000 g, OR = 1.85, 95% CI = 1.25–2.74; 2000–2499 g, OR = 1.57, 95% CI = 1.15–2.13), and groups with higher birth weights also had higher risks of hypertension (3500–3999 g, OR = 1.22, 95% CI = 1.02–1.45; ≥ 4000 g, OR = 1.42, 95% CI = 1.16–1.74).

Conclusions

Excluding the confounding effect of obesity, a U-shaped relationship between birth weight and risk of hypertension was found in children and adolescents in Chinese cities. Birth weight significantly influences SBP but has a minimal effect on DBP. Further basic research on foetal development and programming may shed light on this phenomenon.

The effect of weight loss and weight gain on blood pressure in children and adolescents with obesity

OBJECTIVE

Obesity in childhood is a profound risk factor for hypertension, and weight loss has positive effects on blood pressure (BP). However, the expected effect size on BP from weight reduction in children with obesity is insufficiently described. Therefore, the aim was to investigate the association between changes of degree of obesity and BP levels.

SUBJECTS

This prospective cohort study examined subjects receiving behavioral lifestyle modification treatment who were registered in the Swedish national registry for treatment of childhood obesity (BORIS). A total of 5279 obese subjects (51.3% boys) had repeated BP measurements. The average follow-up time was 32 months. Degree of obesity was expressed as BMI standard deviation score (SDS) and BP as BP SDS.

RESULTS

The mean age at treatment initiation was 10.3 years. The prevalence of hypertensive BP was 15.3% for systolic and 5.5% for diastolic pressure. Both systolic and diastolic BP SDS decreased when a lower BMI SDS was achieved; systolic BP SDS decreased 0.41 [0.33-0.49] and diastolic BP SDS decreased 0.26 [0.20-0.32] per BMI SDS unit reduction. The impact of BMI SDS reduction on BP SDS was greater in subjects with hypertensive levels at treatment initiation, but behavioral modification was an insufficient treatment for 27% of them. Obesity treatment failure increased the risk of developing hypertensive levels; HR = 1.81 [1.38-2.37] (systolic BP) HR = 3.82 [2.34-6.24] (diastolic BP), per unit increase in BMI SDS.

CONCLUSIONS

Weight loss is a key factor for hypertension prevention and treatment in children with obesity. However, its limited effect suggests that additional pharmacological antihypertensive treatment more readily should be considered.

Risk factors and predictive biomarkers of early cardiovascular disease in obese youth

Obesity in childhood and adolescence continues to be a major health issue due to significant health implications and to the economic burden that arise from treating this disease and its complications. Current data show that childhood obesity is no longer just a concern for developed countries, but more significantly affecting developing countries. In adult population, cardiovascular disease is the main cause of mortality and morbidity among obese patients. It is therefore believed that risk factors found in adult patients could also be observed in obese youth. These risk factors will then persist and become progressively worse if obese youth remain obese as they reach adulthood. However, risk reduction is achievable through various prevention and management strategies of obesity and obese children who become nonobese in adulthood have a significant reduction in their risk of developing cardiovascular disease. New biomarkers to improve risk assessment in obese youth are an open research field, which will eventually lead to a more targeted approach in prevention and treatment. Nevertheless, there is still a need for continuous research in understanding the roles of these biomarkers and their potential in risk prediction. Cardiovascular risk modification of childhood obesity depends on a more concerted effort among the various parties involved and particularly a global collaboration to stop the rising prevalence of the epidemic in developing countries.

Features of and preventive measures against hypertension in the young

The Japanese hypertension guidelines report that essential hypertension is detected in 1–3% of upper elementary and high school students during blood pressure (BP) screenings. Hypertension in these age groups is an emerging public health concern mainly attributed to the rising rate of pediatric obesity. Considering the existence of BP tracking phenomenon, early preventive education and instruction are necessary, especially for male students with moderately elevated BP showing a tendency toward obesity, despite the low prevalence of hypertension in high school students. Students with a positive family history of hypertension and those born with low birth weight need the same measures. Lifestyle habits, such as increased alcohol intake, dramatically change once students begin university; thus, early education and instruction regarding the factors influencing BP are necessary. In particular, for male students with higher BP during high school, caution regarding increased body weight is required irrespective of their level of obesity. Young adults aged <40 years should be educated about the association between body weight and hypertension. Particular caution surrounding lifestyle habits, including drinking and smoking, is warranted in male hypertensive subjects because hypertension at a young age is strongly associated with obesity. BP monitoring and the management of obesity should be considered efficient approaches to the detection and treatment of hypertension. For the lifetime prevention of hypertension, it is essential to be aware of one’s health status and learn about healthy lifestyles beginning in childhood. BP measurement may be an appropriate means to achieve this goal.

Body Composition and Serum Total Calcium Were Associated With Blood Pressure Among Children and Adolescents Aged 7-18 in China: A Cross-Sectional Study

Background: This study aimed to assess the prevalence of childhood pre-hypertension and hypertension (elevated blood pressure, EBP) and explore their risk factors, especially the role of body composition and serum total calcium on EBP. Methods: From Nov 2013 to Jul 2014, a cross-sectional study was conducted in Hainan and Shaanxi Provinces in China. Two thousand two hundred eighty-three children and adolescents aged 7-18 underwent anthropometric and blood pressure measurements. Fasting blood was collected and serum total calcium was tested. Blood pressure standards from the updated Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents were used to classify BP groups based on age, sex and stature. Results: The overall prevalence of pre-hypertension and hypertension were 8.36 and 7.06%, respectively. Boys, older age, living in Hainan Province, excess adiposity and higher level of serum total calcium were found to be associated with EBP. Lean subjects had an average 3.87 mmHg decrease in systolic blood pressure (SBP) than normal weight groups. In contrary, overweight/obesity had increased SBP (3.69 mmHg) and diastolic blood pressure (DBP) (2.58 mmHg) than the normal weight group. Participants with high-level serum total calcium had a 1.60 mmHg increased SBP and 1.77 mmHg increased DBP than the low-level group. Compared with normal weight individuals, lean subjects appeared to have decreased odds of EBP (OR = 0.65, 95% CI: 0.43-0.98) but overweight/obese individuals were more likely to have EBP (OR = 2.67, 95% CI: 1.68-4.25). High-level of serum total calcium was associated with increased odds of EBP, the OR (95% CI) was 1.51 (1.17-1.94). The restrict cubic spline presented a linear relationship between serum total calcium and OR of EBP (P < 0.001). Conclusions: Body composition and serum total calcium were positively associated with blood pressure in children and adolescents. Serum calcium could be considered as an untraditional risk factors for high blood pressure screening along with other body composition indexes in clinical settings.

Prevalence of childhood and adolescent overweight and obesity in Asian countries: a systematic review and meta-analysis

INTRODUCTION

We conducted a systematic review and meta-analysis to estimate the prevalence of overweight and obesity in children (aged 5-12 years) and adolescents (aged 12-19 years) in Asian countries. Study design: Systematic review and meta-analysis.

MATERIAL AND METHODS

We comprehensively searched specialised databases for relevant studies conducted in Asian countries between January 1, 1999, and May 30, 2017. Random effects models (using the DerSimonian-Laird method) and generic inverse variance methods were used for quantitative data synthesis. Sensitivity analysis was conducted using the 'leave-one-out' method. Heterogeneity was quantitatively assessed using the I² index. Systematic review registration: CRD42016033061.

RESULTS

Among 22,286 identified citations, 41 studies met the inclusion criteria with n = 71,998 and n = 353,513 for children and adolescents. The pooled prevalence (overall, boys and girls) was 5.8% (n = 4175), 7.0% (n = 2631) and 4.8% (n = 1651) for obesity in children aged 5-11 years; 8.6% (n = 30,402), 10.1% (n = 17,990) and 6.2% (n = 10,874) for obesity in adolescents age 12-19 years. For overweight in children the values for overall, boys and girls were 11.2% (n = 7900), 11.7% (n = 4280) and 10.9% (n = 3698) respectively; and for overweight in adolescents, 14.6% (n = 46,886), 15.9% (27,183), and 13.7% (20,574). These findings were robust in sensitivity analyses. In children and adolescents a higher percentage of boys than girls are obese (children = 7.0 vs. 4.8%, adolescents = 10.1 vs. 6.2%, p < 0.001, respectively). Furthermore, in children and adolescents a higher percentage of boys than girls are overweight (children = 11.7 vs. 10.9%, adolescents = 15.9 vs. 13.7%, p < 0.001, respectively).

CONCLUSIONS

In view of the number of children who are overweight or obese, the associated detrimental effects on health, and the cost to health-care systems, implementation of programmes to monitor and prevent unhealthy weight gain in children and adolescents is needed throughout Asian countries.

Association of Body Fat Mass and Fat Distribution With the Incidence of Hypertension in a Population-Based Chinese Cohort: A 22-Year Follow-Up

BACKGROUND

There have been few studies on the association between the incidence of hypertension and the presence and distribution of body fat. The aim of this article was to evaluate this association.

METHODS AND RESULTS

Data were obtained from the China Health Nutrition Survey, a 22-year cohort study of 12 907 participants. Body mass index and triceps skinfold thickness were used as markers of body fat, whereas waist circumference (WC) was used as a marker of fat distribution. Cox regression was used to examine the association of body mass index, WC, and skinfold thickness with the incidence of hypertension. The interval between the baseline and hypertension diagnosis was the time variable, and hypertension was the end event. The mean age and proportion of men and women were 38.29 and 38.03 years and 45.63% and 54.37%, respectively. Compared with normal WC, abdominal obesity was associated with hypertension (P<0.001; crude hazard ratio, 2.11; 95% confidence interval, 1.89-2.37). Similarly, overweight (crude hazard ratio, 1.75; 95% confidence interval, 1.64-1.87) and obesity (crude hazard ratio, 3.19; 95% confidence interval, 2.80-3.63) were risk factors for hypertension (all P<0.001). When stratified by sex, the results confirmed that WC and body mass index predicted the development of hypertension in both men and women but not skinfold thickness in women.

CONCLUSIONS

Body mass index and WC were independent risk factors for hypertension, but skinfold thickness was a poor marker of body fat and could not be used to predict hypertension.

Paediatric type 2 diabetes in China-Pandemic, progression, and potential solutions

China is gradually taking its place as one of the world's economic giants and concurrently learning to cope with the burden of diseases that are more common in the developed world, such as paediatric type 2 diabetes mellitus. The prevalence of type 2 diabetes has been recently observed among children and adolescents in China; hence, there is a lack of information about the incidence, prevalence, pathogenesis, and pathophysiology of the disease. Diagnosis, treatment, and management have been standardized to a large degree, but there is still a need for data regarding optimal management protocols and how to achieve the best control over current state of the disease. The objective of this review is to consolidate the available information about paediatric diabetes, with a focus on the increasing prevalence of type 2 diabetes in Chinese youth. Here we emphasize the prevention strategies and have included literature with respect to pathogenesis, diagnosis, and treatment published in English and Chinese within the past 10 years.

Excesso de peso e fatores associados em adolescentes de uma capital brasileira

RESUMO: Objetivo: Avaliar a prevalência de excesso de peso (EP) e fatores associados em adolescentes. Métodos: Estudo transversal realizado em escolas públicas e privadas de Goiânia (GO). Foram analisados adolescentes de 12 a 18 anos (n = 1.169) por meio de questionário padronizado. A prevalência de EP foi avaliada pelas curvas de crescimento da Organização Mundial da Saúde (OMS) de Índice de Massa Corporal (IMC) por idade. As associações entre as variáveis sociodemográficas, de antecedentes familiares de obesidade, de estilo de vida e de pressão arterial com o EP foram analisadas por intermédio da razão de prevalência bruta e ajustada por meio da regressão múltipla de Poisson. Resultados: A prevalência de EP foi de 21,2%, sendo 14,1% de sobrepeso e 7,1% de obesidade, com diferenças significativas entre gêneros (26,3% dos rapazes versus 16,8% das moças). Na análise de Poisson, a obesidade materna (RP = 1,86; p = 0,004) foi associada com a maior prevalência de EP no sexo masculino, e aqueles com idade entre 15 e 18 anos tiveram menor prevalência de EP quando comparados àqueles com idade entre 12 e 14 anos (RP = 0,70; p = 0,021). No sexo feminino, a presença de pais obesos (RP = 2,42; p < 0,001) associou-se a maior prevalência de EP, e as moças pertencentes à classe C tiveram menor prevalência de EP (RP = 0,67; p = 0,035). Conclusões: O EP em adolescentes esteve associado ao gênero, à obesidade familiar, e a melhor classificação socioeconômica - fatores que devem ser o foco do planejamento de intervenções específicas na promoção da saúde.

Prevalence of Hypertension in Nigerian Children and Adolescents: A Systematic Review and Trend Analysis of Data from the Past Four Decades

Despite four decades of research, there is no systematic review and trend analysis on paediatric (pre)hypertension in Nigeria. This article reviewed data from cross-sectional studies on the subject. From the initial 9334 articles identified, 30 studies that met the inclusion criteria were systematically reviewed. Data from studies that defined hypertension as blood pressure (BP) greater than the 95th percentile for age, height and sex gave a prevalence of 8.2% [95% confidence interval (CI): 3.6-28.2%] for prehypertension and 5.1% (95% CI: 2.9-8.6%) for hypertension. For studies that defined hypertension as BP greater than 2 SD points from the mean of the population, the prevalence of hypertension was found to be 4.0% (95% CI: 2.8-5.7%). A significant negative trend (Z = -0.89; α < 0.01) with small magnitude (Q = -0.019; 95% CI: -0.070 to 0.028) was found for hypertension in the reviewed population. The prevalence of (pre)hypertension in Nigerian children and adolescents is moderate but has slightly declined over time.

Time trends and factors in body mass index and obesity among children in China: 1997-2011

BACKGROUND

Research on the shift in children's body mass index (BMI) distribution is limited and conditional mean models used in the previous research have limitations in capturing cross-distribution variations in effects. The objectives are to analyze the shift in Chinese children's BMI distribution and to test the associations between BMI distribution and other factors.

METHODS

We analyzed data collected from children 7 to 17 years old from the China Health and Nutrition Survey (CHNS) conducted in 1997, 2000, 2004, 2006, 2009 and 2011, from 2814 participants with 6799 observations. Longitudinal quantile regression (QR) was used to explore the effect of several factors on BMI trends in 2015.

RESULTS

The BMI curves shift to the right in boys and girls, with the distributions becoming wider, indicating a higher proportion of children have become overweight. The 5th, 15th, 50th, 85th and 95th BMI percentile curves all shifted upward from 1997 to 2011, and the higher percentiles had greater increases. The prevalence of overweight and obesity increased in boys and girls between 1997 and 2011, from 6.5 to 15.5% in boys and from 4.6 to 10.4% in girls. Energy intake and parents' BMI levels had a positive association with children's BMI. Per capita income was positively associated with changes in BMI only at the upper percentiles of the BMI distributions in boys. Increased physical activity (PA) was associated with decreased BMI in girls.

CONCLUSIONS

Children in China are becoming increasingly overweight. Energy intake, parental BMI, PA and early menarche age in girls are associated with elevated BMI in children.

Sex differences in the association between body mass index and hypertension - a cross-sectional study in 717 812 adolescents

In order to examine sex-specific differences in the association of body mass index (BMI) and hypertension, we conducted a retrospective, cross-sectional study of 717 812 (402 914 men and 314 898 women) Israeli Jewish adolescents aged 16.0-19.99 years medically screened for military service. A diagnosis of hypertension was established per history or if a mean of 10 separate blood pressure measurements exceeded 140/90, following an initial measurement higher than 140/90. Weight and height were measured. Prevalence of hypertension was 0.42% in men and 0.05% in women. In men, BMI was significantly associated with hypertension from the third decile (odds ratio [OR] 1.67, 1.06-2.65) up to the 10th decile (OR 30.17, 20.83-43.69). In women, we observed a significantly increased risk for hypertension in the ninth decile (OR 3.82, 1.42-10.22) and in the 10th decile (OR 18.92, 7.7-46.51), with no visible trend in lower deciles. BMI effects on hypertension prevalence are different in male and female adolescents.

Relation of body mass index (BMI) to the prevalence of hypertension in children: A 3years' school-based prospective study in Suzhou, China

BACKGROUND

The prevalence of hypertension has been increasing in children and adolescents in China, which is considered to be accompanied with the epidemic of childhood overweight and obesity, but limited prospective studies have investigated the effect of body mass index (BMI) change on blood pressure among children, especially in China.

METHODS

This school-based prospective study compared the blood pressure and prevalence of hypertension in students with different patterns of change in BMI between two periods (childhood and adolescence). 5465 children were followed-up since 2011(childhood) in Suzhou, China and had weight, height and blood pressure measured in 2011(childhood) and 2014(adolescence).

RESULTS

Those who changed from being overweight in childhood to having normal BMI in adolescence had similar mean blood pressures to those who had a normal BMI at both two periods. In contrast, those who were overweight at both two periods or who had a normal BMI in childhood and were overweight in adolescence had higher blood pressure in adolescence than those who had a normal BMI at both two periods. Compared with students who had a normal BMI at both periods, those with combination of abnormal BMI in childhood and adolescence have higher ORs of hypertension (4.83 in boys, 3.44 in girls and 3.73 in total).

CONCLUSION

These results suggest that obesity is a key determinant of blood pressure during childhood, and weight reduction may have important beneficial effects on blood pressure.

Relationship between body mass index changes and blood pressure changes from childhood to adulthood in a general Chinese population: a 26 year cohort follow-up study

The aim of this study was to estimate the relationship between body mass index (BMI) and blood pressure (BP) in a Chinese population with 26 year follow-up. The study included 4211 schoolchildren aged 6-17 years in Hanzhong, Shaanxi Province, China. Body weight, height, waist circumference, and BP were measured in 1987, 1989, 1992, 1995 and 2013. Cox proportional hazards model were fitted to examine the effect of BMI on BP. At the 26 year follow-up, 6.93% of male and 3.43% of female subjects had high SBP, and 12.8% of male and 4.56% of female had high DBP. The average age of subjects with high SBP was 40.3 years in males and 41.4 years in females; while the average age with high DBP was 38.1 years in males and 38.9 years in females. Obese subjects were 2.96 times and 2.88 times more likely to have high SBP and high DBP than normal weight counterparts, respectively; while overweight subjects were 1.81 times and 2.03 times more likely to have high SBP and high DBP, respectively. These findings underscore the urgent need to prevent increasing body weight. Targeting intervention in adolescence may be a critical method for preventing high BP in later life.

Association between indoor air pollutant exposure and blood pressure and heart rate in subjects according to body mass index

This study investigates the effects of high body mass index (BMI) of subjects on individual who exhibited high cardiovascular disease indexes with blood pressure (BP) and heart rate (HR) when exposed to high levels of indoor air pollutants. We collected 115 office workers, and measured their systolic blood pressure (SBP), diastolic blood pressure (DBP) and HR at the end of the workday. The subjects were divided into three groups according to BMI: 18-24 (normal weight), 24-27 (overweight) and >27 (obese). This study also measured the levels of carbon dioxide (CO2), total volatile organic compounds (TVOC), particulate matter with an aerodynamic diameter less than 2.5μm (PM2.5), as well as the bacteria and fungi in the subjects' work-places. The pollutant effects were divided by median. Two-way analysis of variance (ANOVA) was used to analyze the health effects of indoor air pollution exposure according to BMI. Our study showed that higher levels of SBP, DBP and HR occurred in subjects who were overweight or obese as compared to those with normal weight. Moreover, there was higher level of SBP in subjects who were overweight or obese when they were exposed to higher levels of TVOC and fungi (p<0.05). We also found higher value for DBP and HR with increasing BMI to be associated with exposure to higher TVOC levels. This study suggests that individuals with higher BMI have higher cardiovascular disease risk when they are exposed to poor indoor air quality (IAQ), and specifically in terms of TVOC.

The emerging epidemic of hypertension in Asian children and adolescents

Hypertension has become a serious global public health burden because of its high incidence and concomitant risk of cardiovascular disease. Many studies have verified that risk factors, such as hypertension and obesity which are responsible for cardiovascular disease, start in early childhood. In Asian countries, the prevalence of hypertension in the pediatric age group has become more prevalent than ever before with the increasing obesity epidemic. To tackle the epidemic of cardiovascular disease, a leading cause of death and disability of non-communicable diseases in Asian countries, population-based measures aiming at reducing harmful environmental factors to blood pressure and body weight must be applied to individuals in their early childhood, as early as the fetal stage. This review focused on the prevalence of pediatric hypertension in Asian countries and outlined several considerations for accurate blood pressure (BP) measurement and evaluation, along with an overview of pathophysiology of fetal programming and obesity related with childhood hypertension.

Pathological periodontal pockets are associated with raised diastolic blood pressure in obese adolescents

BACKGROUND

Obesity, a well-known risk factor for developing cardiovascular disease (CVD), is associated with chronic periodontitis in adults. This cross-sectional pilot study on obese adolescents was designed to investigate whether periodontal disease in terms of pathological periodontal pockets is associated with raised blood pressure and other risk markers for CVD.

METHODS

The study included 75 obese subjects between 12 to 18 years of age, mean 14.5. Subjects answered a questionnaire regarding health, oral hygiene habits and sociodemographic factors. A clinical examination included Visible Plaque Index (VPI %), Gingival inflammation (BOP %) and the occurrence of pathological pockets exceeding 4 mm (PD ≥ 4 mm). Blood serum were collected and analyzed. The systolic and diastolic blood pressures were registered.

RESULTS

Adolescents with pathological periodontal pockets (PD ≥ 4 mm; n = 14) had significantly higher BOP >25% (P = 0.002), higher diastolic blood pressure (P = 0.008), higher levels of Interleukin (IL)-6 (P < 0.001), Leptin (P = 0.018), Macrophage Chemoattractant Protein-1 (MCP-1) (P = 0.049) and thyroid stimulating hormone (TSH) (P = 0.004) in blood serum compared with subjects without pathological periodontal pockets (PD ≥ 4 mm; n = 61). The bivariate linear regression analysis demonstrated that PD ≥ 4 mm (P = 0.008) and systolic blood pressure (P < 0.001) were significantly associated with the dependent variable "diastolic blood pressure". The association between PD ≥ 4 mm and diastolic blood pressure remained significant (P = 0.006) even after adjusting for potential confounders BMI-sds, age, gender, mother's country of birth, BOP >25%, IL-6, IL-8, Leptin, MCP-1, TSH and total cholesterol in the multiple regression analysis.

CONCLUSION

In conclusion, this study indicates an association between pathological periodontal pockets and diastolic blood pressure in obese adolescents. The association was unaffected by other risk markers for cardiovascular events or periodontal disease. The results call for collaboration between pediatric dentists and medical physicians in preventing obesity development and its associated disorders.

Prevalence of overweight and obesity and their associations with blood pressure among children and adolescents in Shandong, China

BACKGROUND

Obesity and high blood pressure (BP) are public health problems all over the world. Some studies have reported a positive association between them in children and adolescents. The purpose of this study was to assess the prevalence of overweight and obesity and their associations with BP among school children and adolescents in Shandong, an important province in eastern China.

METHODS

In 2011, we conducted a cross-sectional population-representative survey in Shandong, China. A total of 4 898 children and adolescents aged 6-17 years were randomly selected from 140 counties/districts using a multistage random cluster sampling. Weight, height and BP were measured by a trained physician or pediatrician, and information about age, gender and place of residence was obtained using questionnaires. Obesity and high BP were defined according to age- and gender-specific Chinese reference data for children.

RESULTS

A total of 4 898 (100%) children and adolescents provided complete information. The prevalence of overweight, obesity and overweight plus obesity were 10.9%, 8.7% and 19.6%, respectively. Boys were more likely to be overweight or obese than girls (P < 0.05 for overweight; P < 0.001 for obesity). The prevalence of overweight plus obesity was highest among children aged 6-11 years (22.3%). BP and the prevalence of high BP increased with increasing body mass index (BMI). With age and sex adjusted, odds ratios (ORs) for high BP were [OR 2.2;95% CI 1.7-2.8) in overweight and [OR 3.6;95% CI 2.6-4.9] in obese children.

CONCLUSION

The representative survey confirms high prevalence of overweight and obesity among children and adolescents in Shandong. Childhood obesity is a strong risk factor for high BP. Intervention programs should be implemented to combat the growing obesity epidemic.

Prevalence of hypertension and decreased glomerular filtration rate in obese children: results of a population-based field study

BACKGROUND

Obesity has risen considerably in the Western world and the trend is increasing in non-Western, developing countries, as well. Several school screening studies showed the relation between body mass index and hypertension. In adults, obesity is associated with an increased risk of development and progression of kidney disease. However, data at the epidemiological level are limited, both for children and adults. The aim of this study was to determine the prevalence of obesity and evaluate its association with hypertension and glomerular filtration rate (GFR) among children in Turkey.

METHODS

A population-based field study in which individuals were accessed by house visits throughout Turkey has been conducted. The study sample (3622 children; 5-18 years; 49.6% female, mean age 11.88 ± 3.40 years) was selected to represent the Turkish population regarding geographical region, gender and age (5-18 years). Obesity was defined as the body mass index ≥95th percentile for age and gender. The Schwartz formula was used to estimate GFR. Blood pressure (BP) percentile was determined according to age, gender and length.

RESULTS

The prevalence of overweight, obesity and hypertension were 9.3, 8.9 and 6.1%, respectively. Logistic regression analysis revealed urban area (OR 1.50; 95% CI 1.15-1.96; P = 0.003) as an independent risk for obesity and age decreased (OR 0.921; 95% CI 0.890-0.924; P < 0.001) risk for obesity. Obese children had the highest rate of hypertension (11.4 versus 5.6%; P < 0.001; OR 2.17, 95% CI 1.49-3.17; P < 0.001) and stage II hypertension (3.8 versus 0.7%; OR 6.01, 95% CI 2.93-12.33; P < 0.001). Systolic and diastolic BP z-scores were significantly higher in obese children. The mean estimated (eGFR) was lower in obese children (122.7 ± 21.6 versus 129.4 ± 23.1, P < 0.001). The rates of children with eGFR < 90 and <75 mL/min/1.73 m(2) were higher in obese patients, but did not reach statistical significance.

CONCLUSIONS

Our nation-wide population-based field study among children showed that the prevalence of obesity is increasing in Turkey. The prevalence of hypertension and stage II hypertension, BP z-scores and eGFR were associated with obesity. We suggest that obese children are future candidates for chronic kidney disease. Longitudinal research is necessary to better understand these associations. Strategies for the prevention and management of obesity are also important for emerging countries and for children.

Hypertension in children with obesity

The prevalence of obesity related hypertension has dramatically increased in children with the parallel increase in pediatric obesity. This pediatric health problem may adversely affect cardiovascular health in adult life. The pathogenesis of hypertension in obese children is not widely understood. We therefore undertake this review to raise public awareness. Early childhood parameters like birth weight and postnatal weight gain may play important roles in risk for obesity and obesity related hypertension later in childhood and adult life. Further information is required to confirm this origin of hypertension so that appropriate measures are taken in the peri-natal period. The role of sympathetic nervous system has now been well established as one of the principle mechanisms involved in obesity related hypertension. The Renin-Angiotensin system, insulin resistance due to obesity and as a part of metabolic syndrome along with imbalance in adipokines such as leptin and adiponectin, cause activation of the sympathetic system, vasoconstriction, endothelial dysfunction and sodium reabsorption among other perturbations. Multi-step interventions targeting these various mechanisms are required to break the cycle of obesity and metabolic syndrome. Vitamin D deficiency, sleep apnea due to airway obstruction and hyperuricemia may also play a significant role and should not be ignored in its early stages. Obesity is a risk factor for other co-morbid conditions like chronic kidney disease and fatty liver which further accentuate the risk of hypertension. Increased awareness is required to prevent, diagnose and treat obesity related hypertension among the pediatric population.

Association between obesity and metabolic co-morbidities among children and adolescents in South Korea based on national data

Background

Childhood obesity has become a serious public health threat worldwide due to its many short- and long-term adverse health effects. We assessed the association between weight status and metabolic co-morbidities among South Korean children using nationally representative data.

Methods

Data from the 2007-2008 Korea National Health and Nutrition Examination Surveys for 1,526 children aged 10-19 years were used. Logistic regression models were fit to examine the association between weight status [overweight, 85^th percentile ≤ BMI <95^th percentile; obese, BMI ≥95^th percentile; and central obesity, waist circumference ≥90^th percentile, based on 2007 Korean National Growth Charts] and metabolic outcomes.

Results

More obese children had metabolic co-morbidities than normal-weight children (P < 0.05). Boys had higher means BMI than girls, WC, and BP, while girls had higher means of total blood cholesterol and HDL-cholesterol (P < 0.05). Attributable risk of metabolic syndrome was high due to overweight and obesity: 91.1% for central obesity and 29.6% for high TG. Obese children had increased risk of having high BP (adjusted odds ratio (OR): 1.90; 95% CI: 1.05-3.45), dyslipidemia (OR: 6.21; 95% CI: 3.59-10.75), high TG (OR: 6.87; 95% CI: 4.05-11.64), low HDL (OR: 4.46; 95% CI: 2.23-8.89), and ≥2 co-morbidities (OR: 26.97; 95% CI: 14.95-48.65) compared to normal-weight subjects, while the associations between weight status and metabolic outcomes were stronger in boys.

Conclusions

Obesity was strongly associated with metabolic co-morbidities in South Korean children.

Blood pressure tables for Chinese adolescents: justification for incorporation of important influencing factors of height, age and sex in the tables

Background

Elevated blood pressure (BP) in childhood was a predictor of hypertension in adulthood and contributes to the current epidemic of cardiovascular disease. It is necessary to identify abnormal BP in children and adolescents with accurate BP tables based on several crucial factors. The purpose of this study was to identify the important influencing factors of BP of Chinese adolescents.

Methods

BP, height, and body weight were assessed in 32221 normal-weight Chinese adolescents aged 12–17 years. An equal number of 6815 subjects from boys and girls were individually matched by height and age to assess the independent effect of sex on BP; and an equal number of 1422 subjects from each of the age groups (12, 13, 14, 15, 16 and 17 years) were individually matched by sex and height to estimate the independent effect of age on BP. Height of each sex and age was divided into eight height groups - ~5^th, ~10^th, ~25^th, ~50^th, ~75^th, ~90^th, ~95^th, and 95^th ~ percentiles- and the Spearman’s correlation between height percentiles and BP was used to examine the independent effect of height on BP.

Results

Boys had higher systolic BP (SBP) and diastolic BP (DBP) than girls after controlling for age and height. BP increased with age after controlling for sex and height. In each age group, both SBP and DBP increased alongside increasing height in boys and girls.

Conclusions

Sex, age and height are all independent determinants for BP levels in Chinese adolescents. It is essential to incorporate these three factors for the establishment of the BP reference tables.

Prevalence of arterial hypertension among Brazilian adolescents: systematic review and meta-analysis

Background

Cardiovascular diseases are the leading cause of death in the world and are responsible for a high number of disability-adjusted life years. Elevated blood pressure is an independent, linear and continuous risk factor for cardiovascular disease and has also been reported in the young population. Brazil is a country of continental dimensions, and is very heterogeneous with respect to socioeconomic and cultural aspects. Brazilian studies on the subject of hypertension in adolescence are not nationally representative, and this provides a rationale for the conduction of a meta-analysis to assess the magnitude of the problem in the country.

Methods

Hypertension studies in adolescents published from 1990 to September 2010 were searched in six electronic databases. Forest plots of the prevalence of hypertension were built for the overall population and by gender. Heterogeneity was assessed using I² statistics. Meta-regression models were adjusted in order to identify possible sources of heterogeneity.

Results

Of 3,631 articles initially identified, 17 were considered eligible for systematic review. The pooled prevalence of hypertension, estimated through random effects models, was 8.12% (95% CI 6.24 - 10.52) for the total population. Overall, prevalence was higher in males, 8.75% (95% CI 5.81 - 12.96) than females, 6.31%, (95% CI 4.41 - 8.96). Several variables were investigated in the heterogeneity analysis: region of the study, sample size, age and method of blood pressure measurement. The only variables that partially and inconsistently explained the observed heterogeneity (I² = 95.3%) were the region of the country where the study was conducted and sample.

Conclusions

There was a large variation in hypertension prevalence and in the methods used for its evaluation throughout studies with Brazilian adolescents, indicating the need for standardized procedures and validated methods for hypertension measurement. Despite the large observed heterogeneity, and the small number of studies in some regions of Brazil, the pooled prevalence found in both males and females shows that systemic arterial hypertension should be monitored in the population aged 10–20 years and that specific measures are required to prevent and control the disease, as well as its risk factors. Studies that compare regional heterogeneities may contribute to the knowledge of factors associated with increased blood pressure among adolescents.

Effects of weight on blood pressure at rest and during exercise

Body weight (BW) and blood pressure (BP) have a close relationship, which has been accounted for by hormonal changes. No previous study has evaluated the effect of wearing an external weight vest on BP to determine whether there is a simple mechanism between BW and BP. Seventeen healthy volunteers underwent weight reduction (WR) through caloric restriction. Before and after WR, BW, body fat percentage and BP at rest and during exercise were measured. Before and after WR, exercise testing was performed twice with the random allocation of a weight vest (10 kg) during one of the tests. Linear regression was used to detect independent associations between BP and the weight vest, BW and body fat percentage. BW decreased from 89.4 ± 15.4 kg to 79.1 ± 14.0 kg following WR (P<0.001). WR led to significant decreases in BP at rest (from 130.0/85.9 mm Hg to 112.5/77.8 mm Hg, P<0.001 for systolic and diastolic BPs) and during exercise. The weight vest significantly increased BP at rest (to 136.1/90.7 mm Hg before and 125.8/84.6 mm Hg after WR) and during exercise. Linear regression analysis identified an independent association between the weight vest and BP (P=0.006 for systolic BP and P=0.009 for diastolic BP at rest). This study demonstrates that wearing an external weight vest has immediate effects on BP at rest and during exercise independent of BW or body fat. More research is needed to understand the physiological mechanisms between weight and BP.

Trends in blood pressure and body mass index among Chinese children and adolescents from 2005 to 2010

BACKGROUND

The prevalence of obesity, based on body mass index (BMI), among Chinese children and adolescents has increased for decades, but the relationship between trends in blood pressure (BP) and increasing BMI has not been studied.

METHODS

BMI and BP measurements of 391,982 children aged 7-17 years were obtained from surveys in 2005 and 2010. The mean change and 95% confidence intervals (CIs) of BP were calculated, and the association between BMI and BP was assessed by using analysis of covariance and direct adjustment with the BMI distribution of 2005 survey.

RESULTS

The mean systolic BP (SBP) and diastolic BP (DBP) increased 1.5 mm Hg (95% CI = 1.4-1.7 mm Hg) and 1.1 mm Hg (95%CI = 1.1-1.2 mm Hg) for boys and 1.2 mm Hg (95% CI = 1.1-1.3 mm Hg) and 1.0 mm Hg (95% CI = 1.0-1.1 mm Hg) for girls from 2005 to 2010, respectively. After adjustment for BMI, SBP and DBP in 2010 were 0.8mm Hg (95% CI = 0.8-0.9mm Hg) and 0.8mm Hg (95% CI = 0.7-0.8mm Hg) higher than in 2005, respectively (all P < 0.01). With adjustment for difference in BMI distribution in 2005 and 2010, the mean increase of SBP decreased by 40.5% and that of DBP by 26.9%.

CONCLUSIONS

BP among Chinese children and adolescents was on the rise from 2005 to 2010, which was consistent with the hypothesis that the rise in BP was in part attributable to the rise in BMI.

The changing face of pediatric hypertension in the era of the childhood obesity epidemic

Historically, hypertension in childhood was thought to be an uncommon diagnosis, usually related to an underlying condition, most often parenchymal renal disease. Primary hypertension in childhood was felt to be quite rare. However, the worldwide childhood obesity epidemic has had a profound impact on the frequency of hypertension and other obesity-related conditions with the result that primary hypertension should now be viewed as one of the most common health conditions in the young. This review will present updated data on the prevalence of hypertension in children and adolescents, the impact of the childhood obesity epidemic on hypertension prevalence and blood pressure levels, shifts in how often primary hypertension is being diagnosed in childhood, and an overview of the pathophysiology of obesity-related hypertension. It is hoped that improved understanding of the significance of these issues will lead to improved recognition and treatment, which will be the key to averting an epidemic of cardiovascular disease in adulthood.

Trends in overweight and obesity among children and adolescents in China from 1981 to 2010: a meta-analysis

Background

Overweight/obesity is a serious public health problem that affects a large part of the world population across all age and racial/ethnic groups. However, there has not been a meta-analysis of the prevalence of childhood and adolescent overweight/obesity in China during the past 30 years.

Methods

The China National Knowledge Infrastructure and Wanfang DATA, MEDLINE, EMBASE and Cumulative Index to Nursing and Allied Health Literature were searched for relevant studies published between January 1970 and June 2012. The prevalence of overweight/obesity over time was pooled using Stata/SE, version 9. Summary statistics (odds ratios, ORs) were used to compare sex-specific and urban-rural preponderance of overweight/obesity using Review Manager.

Results

After screening 1326 papers, we included 35 papers (41 studies), most of medium quality. The prevalence of overweight/obesity increased from 1.8% (95% confidence interval [CI], 0.4%–3.1%) and 0.4% (95% CI, −0.1% to −0.8%) respectively in 1981–1985 to 13.1% (95% CI, 11.2%–15.0%) and 7.5% (95% CI, 6.6%–8.4%) respectively in 2006–2010. The average annual increase was 8.3% and 12.4% respectively. Boys were more likely to be overweight/obese than girls (OR, 1.36; 95% CI, 1.24–1.49 and OR, 1.68; 95% CI, 1.52–1.86 respectively). The prevalence of overweight/obesity was higher in urban areas than in rural areas (OR, 1.66; 95% CI, 1.54–1.79 and OR, 1.97; 95% CI, 1.68–2.30 respectively). For age-specific subgroup analyses, both overweight and obesity increased more rapidly in the toddler stage than in other developmental stages. Sensitivity analyses showed that sample-size differences, study quality, overweight/obesity criteria and geographical distribution affected overweight/obesity prevalence.

Conclusions

Toddlers and urban boys were at particularly high risk; the prevalence in these groups increased more rapidly than in their counterparts. Public health prevention strategies are urgently needed to modify health behaviors of children and adolescents and control overweight/obesity in China.