Comparison of blood pressure levels among children and adolescents with different body mass index and waist circumference: study in a large sample in Shandong, China

Elevated blood pressure among children born to women with obstructed labour in Eastern Uganda: a cohort study

BACKGROUND

Globally, high systolic blood pressure accounts for 10.8 million deaths annually. The deaths are disproportionately higher among black people. The reasons for this disparity are poorly understood, but could include a high burden of perinatal insults such as birth asphyxia. Therefore, we aimed to assess the incidence of elevated blood pressure and to explore associated factors among children born to women with obstructed labour.

METHODS

We followed up children born to women with obstructed labour aged 25 to 44 months at Mbale regional referral hospital that had participated in the sodium bicarbonate trial ( Trial registration number PACTR201805003364421) between October 2021 and April 2022. Our primary outcome was elevated blood pressure defined as blood pressure (either systolic or diastolic or both) ≥ the 90th percentile for age, height, and sex in the reference population based on the clinical practice guideline for screening and management of high blood pressure in children and adolescents. We used logistic regression to estimate odds ratios between selected exposures and elevated blood pressure.

RESULTS

The incidence of elevated blood pressure was (39/140, 27.9%: 95% (CI: 20.6-36.1)). Participants aged three years and above had twice the odds of elevated blood pressure as those aged less than three years (Adjusted odds ratio (AOR) 2.46: 95% CI (1.01-5.97). Female participants had 2.81 times the odds of elevated blood pressure as their male counterparts (AOR 2.81 95% CI (1.16-6.82). Participants with reduced estimated glomerular filtration rate had 2.85 times the odds of having elevated blood pressure as those with normal estimated glomerular filtration rate (AOR 2.85 95% CI (1.00-8.13). We found no association between arterial cord lactate, stunting, wealth index, exclusive breastfeeding, food diversity and elevated blood pressure.

CONCLUSION

Our findings show a high incidence of elevated blood pressure among children. We encourage routine checking for elevated blood pressure in the pediatric population particularly those with known risk factors.

Waist circumference and blood pressure in Brazilian children

AIM

We aimed to examine the association between waist circumference and blood pressure (BP) in children at 9 years of age.

METHODS

This was a cross-sectional study of 142 children enrolled in a cohort study conducted at the participants' homes in southern Brazil. SBP and DBP were measured using the auscultatory method. Waist circumference was measured with a 150-cm flexible tape. Logistic regression adjusted for important covariates was used to examine the association between waist circumference and BP.

RESULTS

The prevalence of high BP in children was 20.4%. High BP was more prevalent in males (69.0%). The average SBP/DBP on the right arm was 98/60 mmHg in females and 101/62 mmHg in males. An important proportion of children was classified as having high BP and BMI (44.8%) and waist circumference (50.0%) > 85th percentile (P < 0.01). Logistic regression analysis showed that children with high BMI and waist circumference were 3.91 (95% confidence interval, 1.31-11.71, P = 0.015) times more likely to have high BP than those ≤85th percentile, even after adjusting for other covariates.

CONCLUSION

This study revealed that waist circumference was associated with both SBP and DBP in 9-year-old children and increased waist circumference was the determining factor of cardiovascular risk.

The dose-response relationship between BMI and hypertension based on restricted cubic spline functions in children and adolescents: A cross-sectional study

Background

A high body mass index (BMI) is a major risk factor for hypertension. The purpose of this study was to investigate the association between the BMI and hypertension in children and adolescents.

Methods

We analyzed physical examination data from 29,810 students aged 6-14 years old. A restricted cubic spline (RCS) function was used to investigate the dose-response relationship between the BMI and hypertension.

Results

The prevalence of hypertension was 9.91%, followed by 11.71% in males and 7.9% in females, respectively. Compared to the normal weight group, the odds risk (OR) for hypertension in the overweight group was 1.729, and the OR for hypertension in the obesity group was 3.089. After adjusting for potential confounders, the adjusted ORs were 1.620 [95% confidence interval (CI): 1.457-1.800] in the overweight group and 3.092 (95% CI: 2.824-3.385) in the obesity group. According to the multivariate RCS regression analysis, there was a significant non-linear dose-response association between the BMI and the risk of hypertension (all P-values for non-linear < 0.001).

Conclusion

The dose-response relationship analysis showed that the association strength of hypertension increased non-linearly along with the continuous change of BMI in children and adolescents.

Effect of changes in body mass index and waist-to-height ratio on blood pressure in 11- to 13-year-old children: a prospective population study

BACKGROUND

Existing evidence about associations between change in body mass index (BMI) and waist-to-height ratio (WHtR) change and high blood pressure are relatively limited.

AIMS

We aimed to investigate the associations of general overweight (based on BMI) and abdominal obesity (based on WHtR) change with high blood pressure in Chinese children.

SUBJECTS AND METHODS

A school-based cohort study in Ningbo region (China) was conducted among children with baseline evaluations in October 2016 with follow-up two years later. A total of 1432 children aged 11-13 years participated in this study.

RESULTS

Our results showed that a change from normal BMI or WHtR to overweight or abdominal obesity in children was associated with high blood pressure (adjusted odds ratio (AOR), 2.62; p<0.05 or AOR, 2.79; p<0.05, respectively). In addition, an increased risk of high blood pressure was observed in children who maintained overweight or abdominal obesity (AOR, 1.67; p<0.05 or AOR, 1.69; p<0.05, respectively), but not in children who experienced remission to non-excess weight. Interestingly, children who increased BMI or WHtR had greater impact on SBP than on DBP.

CONCLUSION

The 2-year longitudinal study indicated that general overweight or abdominal obesity can predict the risk factor of high blood pressure in children. However, children who remitted to non-excess weight did not exhibit an increased risk of high blood pressure.

Disparities in the Prevalence of Childhood Obesity-Related Comorbidities: A Systematic Review

Background

Non-communicable diseases among children are serious consequences of childhood obesity. However, less is known about the disparities in childhood obesity comorbidities burden. This review describes the salient pattern of disparities in the prevalence of childhood obesity-related non-communicable diseases and relevant inequalities in both high- and low/medium-income countries.

Method

A systematic literature search was performed in MEDLINE, Embase, CINAHL, PsycInfo, Scopus, and Web of Science databases by two independent reviewers. Inclusion criteria were as follows: age 2–18 years; the prevalence or incidence of childhood obesity comorbidities reported; and studies published in English from January 2010 to date. No restrictions on the setting. The prevalence data were analyzed using range and median for subgroups based on the country's development status, gender, and geographical region.

Results

Our search identified 6,837 articles, out of which we examined 145 full-text articles and included 54 articles in the analysis. The median prevalence of childhood obesity-related hypertension was 35.6 vs. 12.7% among middle- and low-income countries compared with high-income countries; 37.7 vs. 32.9% among boys compared with girls; and 38.6, 25.3, and 20.1% in Asia, South America, and Europe, respectively. For metabolic syndrome, the median prevalence was 26.9 vs. 5.5% among middle- and low-income countries compared with high-income countries; 55.2 vs. 12.0% among boys compared with girls; and 40.3, 25.8, and 7.7% in South America, Asia, and Europe, respectively. The prevalence of childhood obesity-related non-alcoholic fatty liver disease was 47.5 vs. 23% among middle- and low-income countries compared with high-income countries; and 52.1, 39.7, and 23.0% in Asia, South America, and Europe, respectively. The median prevalence of dyslipidemia was 43.5 vs. 63% among middle- and low-income countries compared with high-income countries; 55.2 vs. 12.0% among boys compared to girls; and 73.7 and 49.2% in Australia and Europe, respectively.

Conclusion

There are disparities in the prevalence of childhood obesity-related hypertension, metabolic syndrome, and non-alcoholic fatty liver disease, with middle- and low-income countries, boys, and Asian region having higher prevalence. Implementing targeted interventions for childhood obesity comorbidities should consider socioeconomic disparities and strengthening of research surveillance methods for a better understanding of non-communicable disease burden in the pediatric population.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO, identifier: CRD42021288607.

The prevalence of hypertension and elevated blood pressure and its correlation with overweight/obesity among students aged 6-17 years in Suzhou

OBJECTIVES

Lifestyle changes have led to an increase in the prevalence of hypertension in Chinese children and adolescents. The aim of this study was to analyze the prevalence of hypertension and its association with overweight and obesity among students aged 6-17 years in Suzhou. This retrospective analysis included physical examination data of primary and junior high school students in Suzhou Industrial Park from 2016 to 2019.

METHODS

Elevated blood pressure and hypertension were defined using blood pressure criteria appropriate for age, sex, and height percentile. Overweight and obesity were defined using the 2007 diagnostic criteria proposed by the World Health Organization for school-age children. Logistic regression analysis was used to evaluate the association between hypertension and overweight and obesity.

RESULTS

A total of 128,113 students were included. The prevalence of elevated BP and hypertension was 9.92% and 13.56%, respectively. The incidence of high blood pressure was higher in boys than in girls and increased with an increase in body mass index (BMI). The prevalence of hypertension in obese boys and girls (27.07% and 27.49%, respectively) was 2.3-fold and 2.8-fold higher than that in normal-weight boys and girls (11.58% and 9.83%, respectively).

CONCLUSIONS

Blood pressure was positively correlated with BMI, and the risk of high blood pressure due to overweight/obesity was 10.44%. Overweight and obesity significantly increased the risk of hypertension in students aged 6-17 years in Suzhou. Targeted weight-loss programs during childhood and adolescence may reduce the risk of hypertension in adulthood.

Neutrophil to Lymphocyte Ratio Is Increased and Associated With Left Ventricular Diastolic Function in Newly Diagnosed Essential Hypertension Children

Aim: Hypertension is associated with cardiac structural and functional changes, including left ventricular hypertrophy (LVH) and LV systolic dysfunction diastolic dysfunction. Neutrophil-to-lymphocyte ratio (NLR) is a novel inflammatory biomarker associated with cardiovascular diseases. The current study aimed to evaluate NLR in children with newly diagnosed essential hypertension and its relationship between blood pressure and cardiac changes. Methods and Subjects: Sixty-five children with newly diagnosed essential hypertension and 54 healthy children were included. Clinical characteristics, blood cell counts, and biochemical parameters were collected. LVH was assessed by calculation of LV mass index (LVMI), and LV systolic function was evaluated by measuring LV ejection fraction and fractional shortening. LV diastolic function was primarily assessed with E/E' ratio by Doppler and echocardiography. Results: The hypertension children had significantly higher LVMI and E/E' ratio than the controls, whereas there was no difference in LV systolic function between the two groups. The NLR was significantly higher in the hypertension group than the control group. Moreover, NLR was positively correlated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) levels in the hypertension group. Additionally, a significantly positive correlation between NLR and E/E' ratio was found in the hypertension group. However, NLR was not related to LVH and LV systolic function indicators in hypertension children. Conclusion: NLR is elevated in hypertension children, and it is associated positively with office blood pressure levels. Moreover, NLR may help assess LV diastolic function in hypertension children.

Trends in Prevalence of Hypertension and Hypertension Phenotypes Among Chinese Children and Adolescents Over Two Decades (1991-2015)

Background: Hypertension is a leading cause of cardiovascular-related morbidity and mortality. Elevated blood pressure (BP) in children is related to long-term adverse health effects. Until recently, few studies have reported the secular trend and associated factors of hypertension phenotypes in Chinese children and adolescents. Methods: From the China Health and Nutrition Survey (CHNS) 1991-2015, a total of 15,143 records of children aged 7-17 years old were included. Following definitions of hypertension from the Chinese Child Blood Pressure References Collaborative Group, we estimated the prevalence of prehypertension, hypertension, stage 1 hypertension, stage 2 hypertension and its phenotypes (ISH, isolated systolic hypertension; IDH, isolated diastolic hypertension; SDH, combined systolic and diastolic hypertension). General estimation equation was used to analyze the trends in the prevalence of hypertension and hypertension phenotypes, and a multivariable logistic regression was constructed to explore the associated factors. Results: During 1991-2015, increasing trends were revealed in BP and hypertension prevalence (P < 0.001) in Chinese children and adolescents. For ISH, IDH and SDH, the age-standardized prevalence increased dramatically from 0.9 to 2.2%, from 6.2 to 14.1%, and from 1.4 to 2.9%, respectively (all P < 0.001). Adolescents aged 13-17 years (OR = 1.76, 95% CI: 1.56-1.97, P < 0.001), general obesity (OR = 2.69, 95% CI: 2.10-3.44, P < 0.001) and central obesity (OR = 1.49, 95% CI: 1.21-1.83, P < 0.001) were positively associated with hypertension, whereas the South region (OR = 0.65, 95% CI: 0.58-0.73, P < 0.001) was a negative factor. Furthermore, body mass index (BMI) and general obesity were linked to the presence of ISH, IDH and SDH. Age, waist circumference (WC) and central obesity were additionally associated with ISH, and sex, age, urban/rural setting, North/South region, WC and central obesity were additionally associated with IDH. Conclusion: BP levels and prevalence of hypertension and phenotypes increased dramatically in Chinese children and adolescents from 1991 to 2015. Regional discrepancy, demographic features, BMI, WC and overweight/obesity status were associated factors of hypertension among youths.

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.

Secular trends in hypertension and elevated blood pressure among Korean children and adolescents in the Korea National Health and Nutrition Examination Survey 2007-2015

The prevalence of elevated blood pressure (BP) among US children and adolescents has reportedly declined over the past decade. As no Korean data have been analyzed, we aimed to determine recent trends in BP levels among Korean children and adolescents. This study examines data from the Korea National Health and Nutrition Examination Survey segregated into 3 time periods (2007-2009, 2010-2012, and 2013-2015). A total of 7804 Korean children and adolescents aged 10-18 years were included in the analysis. Hypertension (≥95th percentile) and elevated BP (>90th percentile) were defined using the sex-, age-, and height-specific BP standards from 2017 American Academy of Pediatrics guidelines. Mean systolic BP from 2007-2009 to 2013-2015 increased by 3.9 mm Hg, and there was no significant change in diastolic BP. Body mass index (BMI) z-scores significantly increased in the total population from 2007-2009 to 2013-2015. In 2013-2015, the prevalence rates of elevated BP and hypertension were 8.8% and 9.0%, respectively. The prevalence of hypertension in 2013-2015 increased in the total population compared with those in 2007-2009, especially in the obese subgroup, in which the hypertension prevalence was 27.7% in 2013-2015. The prevalence of elevated BP increased during these time period. Associated factors were sex, age, BMI z-score, and survey period for elevated BP; and sex, age, and BMI z-score for hypertension. During our study, mean systolic BP increased, and the prevalence of hypertension in 2013-2015 increased in the pediatric population. A possible influencing factor is obesity, and further long-term data are necessary.

Prevalence and risk factors of childhood hypertension from birth through childhood: a retrospective cohort study

The prevalence of childhood hypertension is recognized as an important parameter of cardiovascular risk in adults. This retrospective study aimed to ascertain the prevalence and risk factors for hypertension from birth through childhood as of 2014. Stratified cluster sampling was used to select 17,007 participants (5971 with biochemical indexes available) aged 6-12 years on two avenues per region in urban, suburban, and rural areas. The prevalence of hypertension was 12.55%; children with obesity combined with rural residence, low family income, birth weight (<3000 g) (BWP₂₅) or >10 months of breastfeeding had a significantly elevated prevalence of hypertension (37.06%, 30.41%, 30.04%, and 30.84%, respectively). Obesity and heart rate were the significant anthropometric determinants; gestational hypertension, BWP25 and >10 months of breastfeeding were the significant perinatal determinants; rural residence was the significant socioeconomic determinant; fasting blood glucose, triglycerides, and low-density lipoprotein cholesterol were the significant serum biochemical determinants; and red blood cell counts and platelet counts were the significant haematological determinants of childhood hypertension. The adjusted R² values were 14.45% and 24.88% in the full models excluding and including serum indexes, respectively. We observed a notable prevalence of hypertension in a large paediatric sample. Obesity, high heart rate, BWP25, >10 months of breastfeeding, low family income, rural residence, abnormal lipid metabolism, and abnormal blood counts were associated with an increased risk of hypertension.

Identification of dietary patterns associated with elevated blood pressure among Lebanese men: A comparison of principal component analysis with reduced rank regression and partial least square methods

BACKGROUND

To examine the associations of dietary patterns with odds of elevated Blood Pressure (BP) among Lebanese adult males using principal component analysis (PCA), and compare the results to two other data reduction methods, including reduced rank regression (RRR) and partial least-squares (PLS) regression.

METHODS

Data from the National Nutrition and Non-Communicable Disease Risk Factor Survey conducted in Lebanon between years 2008 and 2009 were used. Dietary intake data were collected by a 61-item food frequency questionnaire (FFQ). In addition, anthropometric and blood pressure measurements were obtained following standard techniques. For the purpose of this study, data of males older than 20 years with no history of chronic diseases were selected (n = 673). Elevated BP was indicated if the systolic blood pressure was > = 130mm Hg and/or the diastolic blood pressure > = 85 mm Hg. Dietary patterns were constructed using PCA, PLS and RRR and compared based on the performance to identify plausible patterns associated with elevated BP. For PLS and RR, the response variables were BMI, waist circumference and percent body fat. Multiple logistic regression was used to evaluate the associations between the dietary pattern scores of each method and risk of elevated BP.

RESULTS

Three dietary patterns were identified using PCA: Western, Traditional Lebanese, and Fish and alcohol. Both the Western and the Traditional Lebanese patterns were associated with higher odds of elevated BP in the study population (OR = 1.23, CI 1.03, 1.46; OR = 1.29, CI 1.09, 1.52 respectively). The comparison among the three methods for dietary patterns derivation showed that PLS and RRR derived patterns explained greater variance in the outcome (PCA: 1.2%; PLS: 14.1%; RRR: 15.36%) and were significantly associated with elevated BP, while the PCA dietary patterns were descriptive of the study population's real dietary habits (PCA: 23.6%; PLS: 19.8%; RRR: 11.3%).

CONCLUSIONS

The Western and Traditional Lebanese dietary patterns were associated with higher odds of elevated BP among Lebanese males. The findings of this study showed that, compared to PCA, the use of RRR method resulted in more significant associations with the outcome while the PCA-derived patterns were more related to the real habits in the study population.

Waist circumference as high blood pressure predictor in school age children

Childhood hypertension is becoming more common with the increasing numbers of child obesity, which has encouraged new studies to identify a good anthropometric marker for high blood pressure levels. The objective this study was to identify the best anthropometric predictor of risk of hypertension in children between 8-10 years of age. The Children were evaluated for socioeconomic status and their blood pressure (BP), weight, height, waist circumference (WC) and percentage of body fat (PBF) were measured. The study included 445 children, of which 50.1% were females. The prevalence of obesity defined by body mass index (BMI) was 14.6%. Increased BP was found in 3.4% and 2.2% of the children, considering the pre-hypertension and hypertension classifications respectively. The arithmetic mean of BP value correlated significantly with BMI, WC and PBF. After height control, the correlations that were maintained significant were between WC and systolic blood pressure (SBP) and between WC and diastolic blood pressure (DBP). The variable with the highest predictive power of the occurrence of hypertension was WC. The results indicate that, in this population of children between 8 and 10 years old, WC is a measurement of higher value in predicting increased BP.

Body mass index, waist circumference, body fat mass, and risk of developing hypertension in normal-weight children and adolescents

BACKGROUND AND AIMS

We prospectively examined the association between three adiposity indices, including body mass index (BMI), waist circumference (WC), and percentage of body fat (PBF), and risk of hypertension in normal-weight Chinese children.

METHODS AND RESULTS

The current study included 1526 (713 boys and 813 girls) normal-weight Chinese children (age 6-14 years old), who were free of hypertension at baseline (2014). Heights, body weight, WC, and PBF (estimated by bioelectrical impedance analysis) were measured at the baseline. Blood pressure was repeatedly measured in 2014, 2015 and 2016. Hypertension was defined as either high systolic blood pressure and/or high diastolic blood pressure, according to age- and sex-specific 95th percentile for Chinese children. We used Cox proportional hazards model to calculate the association between exposures and hypertension. We identified 88 incident hypertension cases during two years of follow up. High BMI was associated with high risk of developing hypertension after adjusting for potential confounders. The adjusted hazard ratio for hypertension was 2.88 (95% CI: 1.24, 6.69) comparing two extreme BMI quartiles. Each SD increase of BMI (≈1.85 kg/m²) was associated with a 32% higher likelihood to developing hypertension (Hazard ratio = 1.32; 95% CI: 1.003, 1.73). In contrast, we did not find significant associations between WC or PBF and higher hypertension risk (p-trend >0.2 for both).

CONCLUSION

High BMI, but not WC and PBF, was associated with high risk of hypertension in normal-weight Chinese children.

Modeling the random effects covariance matrix for longitudinal data with covariates measurement error

Longitudinal data occur frequently in practice such as medical studies and life sciences. Generalized linear mixed models (GLMMs) are commonly used to analyze such data. It is typically assumed that the random effects covariance matrix is constant among subjects in these models. In many situations, however, the correlation structure may differ among subjects and ignoring this heterogeneity can lead to biases in model parameters estimate. Recently, Lee et al developed a heterogeneous random effects covariance matrix for GLMMs for error-free covariates. Covariates measured with error also happen frequently in the longitudinal data set-up (eg, blood pressure and cholesterol level). Ignoring this issue in the data may produce bias in model parameters estimate and lead to wrong conclusions. In this paper, we propose an approach to properly model the random effects covariance matrix based on covariates in the class of GLMMs, where we also have covariates measured with error. The resulting parameters from the decomposition of random effects covariance matrix have a sensible interpretation and can be easily modeled without the concern of positive definiteness of the resulting estimator. The performance of the proposed approach is evaluated through simulation studies, which show that the proposed method performs very well in terms of bias, mean squared error, and coverage rate. An application of the proposed method is also provided using a longitudinal data from Manitoba follow-up study.

What's new in paediatric hypertension?

Paediatric hypertension predisposes to hypertension and cardiovascular disease in adult life. Despite clear guidelines, there remains a lack of screening. Diagnosis remains challenging given the high rate of false-positive high blood pressure (BP) readings at a single visit; thus, multiple visits are required to confirm the diagnosis. Depending on the normative data sets used, hypertension in overweight and obese children can be underestimated by up to 20%. Specific BP targets are required for subgroups such as adolescents, children with chronic kidney disease (CKD) and type 1 diabetes. High dietary salt intake is a risk factor for cardiovascular disease. Given the rise in processed food consumption, children in developed nations are likely to benefit from salt restriction at a population-based level.

Is high waist circumference and body weight associated with high blood pressure in Iranian primary school children?

INTRODUCTION AND OBJECTIVES

The prevalence of overweight, abdominal obesity and hypertension among children has increased worldwide including Iran over several decades. We carried out a study to provide current estimates of the prevalence and trends of hypertension, overweight and obesity along with the relationship between weight status and hypertension in Iranian school-children.

METHOD

This study was carried out among 1184 fifth-grade students, whose ages ranged from 11 to 14 years. Body weight, body mass index (BMI), height and waist circumference (WC), systolic (SBP) and diastolic blood pressure (DBP) were measured.

RESULTS

22.04 and 5.32 % of students were overweight and obese, respectively. The prevalence of overweight and obesity was significantly higher among girls than boys (all p = 0.02), whereas the prevalence of hypertension was significantly higher in boys than girls (p = 0.001). Although 27 % of boys and 24.32 % of girls had abdominal obesity, no significant associations were reported between abdominal obesity and sex (p = 0.12). The prevalence of hypertension in children with normal weight, overweight and obesity, was 3, 9.7 and 17.8 %, respectively (p < 0.01). We have obtained that the mean values of weight and WC were significantly higher in boys than girls. Based on linear regression, every 1 cm increase in abdominal circumference leads to an estimated DBP and SBP increase of 0.173 and 0.164 mmHg, respectively (p < 0.05).

CONCLUSIONS

This study showed a high prevalence of hypertension and obesity in a school-based population in Tehran, Iran, in which the prevalence of hypertension was significantly and positively correlated with weight and WC.

Comparison of body mass index with abdominal obesity for identifying elevated blood pressure in children and adolescents: The SNEC study

Body mass index (BMI) and waist circumference (WC) are two common ways to measure obesity. There is a debate, however, about which of these two measures are more closely associated with elevated blood pressure (BP). The aim of this study is to investigate the prevalence of obesity and whether BMI and WC is better associated with elevated BP in children and adolescents. A representative sample of 8613 Chinese youth aged 7-17 years from seven cities in Northeastern China was selected and measurements of height, weight, WC, BP were taken from 2012 to 2013. The average age of the children was 11.3±2.3years. The prevalence of overweight/obese and abdominal obesity in the subjects was 35% and 44.8%, respectively. We found that both BMI and WC were significantly associated with elevated BP. An increase of 1kgm^-2 in BMI was associated with a 1.10 (1.08-1.12, 95% CI) increased risk of an elevated BP diagnosis in boys, and a 1.14 (1.11-1.16, 95% CI) increased risk in girls. Meanwhile, a 1cm increase in WC correlated with a 1.03 (1.02-1.04, 95% CI) and a 1.05 (1.04-1.06, 95% CI) increased risk of higher BP in boys and girls, respectively. Compared to the normal-weight youth, subjects with elevated BMI (BMI>85th) had higher risk of elevated BP (OR: 2.42, 95% CI: 2.13-2.75) than that of in elevated WC participants (OR: 2.00, 95% CI: 1.77-2.27). Therefore, BMI may associate better with elevated BP than WC in Chinese youth in our Seven Northeastern Cities study.

Diagnosis, Epidemiology, and Management of Hypertension in Children

National guidelines for the diagnosis and management of hypertension in children have been available for nearly 40 years. Unfortunately, knowledge and recognition of the problem by clinicians remain poor. Prevalence estimates are highly variable because of differing standards, populations, and blood pressure (BP) measurement techniques. Estimates in the United States range from 0.3% to 4.5%. Risk factors for primary hypertension include overweight and obesity, male sex, older age, high sodium intake, and African American or Latino ancestry. Data relating hypertension in childhood to later cardiovascular events is currently lacking. It is known that BP in childhood is highly predictive of BP in adulthood. Compelling data about target organ damage is available, including the association of hypertension with left ventricular hypertrophy, carotid-intima media thickness, and microalbuminuria. Guidelines from both the United States and Europe include detailed recommendations for diagnosis and management. Diagnostic standards are based on clinic readings, ambulatory BP monitoring is useful in confirming diagnosis of hypertension and identifying white-coat hypertension, masked hypertension, and secondary hypertension, as well as monitoring response to therapy. Research priorities include the need for reliable prevalence estimates based on diverse populations and data about the long-term impact of childhood hypertension on cardiovascular morbidity and mortality. Priorities to improve clinical practice include more education among clinicians about diagnosis and management, clinical decision support to aid in diagnosis, and routine use of ambulatory BP monitoring to aid in diagnosis and to monitor response to treatment.

Role of waist measures in addition to body mass index to assess the hypertension risk in children

AIM

This study aimed to evaluate whether waist measures, including waist circumference (WC) and waist-to-height ratio (WHtR), can improve the ability of body mass index (BMI) to assess the hypertension risk when used as continuous variables.

METHODS

In this cross-sectional study, 82 432 Chinese children aged 9-17 years were included. Elevated BP was defined using age-sex-and-height-specific references. Logistic regression model and area under the receiver operating characteristic curve (AUC) were performed after BMI and waist measures were converted into age-and-sex-based z-scores.

RESULTS

WHtR, but not WC, was associated with elevated BP after adjusting for BMI, with the odds ratios ranging between 1.14 (95% confidence interval: 1.04, 1.25) and 1.30 (1.21, 1.39) for one unit increase in WHtR z-score. Combined use of BMI and WHtR z-scores showed a significantly larger AUC than BMI alone (p < 0.05), while joint use of BMI and WC was not better than BMI alone.

CONCLUSION

WHtR, rather than WC, provided further information on hypertension risk beyond that provided by BMI alone when used as a continuous variable. This study suggests WHtR, in addition to BMI, should be included for the assessment of childhood adiposity in routine paediatric practice.

Introduction of complementary feeding before 4months of age increases the risk of childhood overweight or obesity: a meta-analysis of prospective cohort studies

The association between the age at introduction of complementary feeding and the risk of overweight or obesity during childhood has been hotly debated, but the result remains uncertain. This meta-analysis of prospective cohort studies attempted to evaluate this association, as well as provide evidence for infant feeding recommendations. The PubMed, Embase, and Cochrane databases were systematically searched for relevant original articles published prior to March 1, 2015 that met predefined inclusion criteria. The pooled relative risks (RRs) and corresponding 95% confidence intervals (CIs) were calculated using fix-effect or random-effect models, which were chosen based on heterogeneity among studies. Ten articles consisting of 13 studies, where 8 measured being overweight as an outcome and 5 measured being obese, were included in this meta-analysis. There were a total of 63,605 participants and 11,900 incident cases in the overweight studies, and 56,136 individuals and 3246 incident cases in the obese studies. The pooled results revealed that introducing complementary foods before 4months of age compared to at 4 to 6months was associated with an increased risk of being overweight (RR, 1.18; 95% CI, 1.06-1.31) or obese (RR, 1.33; 95% CI, 1.07-1.64) during childhood. No significant relationship was observed between delaying introduction of complementary foods after 6months of age, and being overweight (RR, 1.01; 95% CI, 0.90-1.13) or obese (RR, 1.02; 95% CI, 0.91-1.14) during childhood. The results of this study suggest that the introduction of complementary foods to infants before 4months of age should be avoided to protect against childhood obesity.

Early Weight Gain, Linear Growth, and Mid-Childhood Blood Pressure: A Prospective Study in Project Viva

In recent years, the prevalence of hypertension and prehypertension increased markedly among children and adolescents, highlighting the importance of identifying determinants of elevated blood pressure early in life. Low birth weight and rapid early childhood weight gain are associated with higher future blood pressure. However, few studies have examined the timing of postnatal weight gain in relation to later blood pressure, and little is known regarding the contribution of linear growth. We studied 957 participants in Project Viva, an ongoing US prebirth cohort. We examined the relations of gains in body mass index z-score and length/height z-score during 4 early life age intervals (birth to 6 months, 6 months to 1 year, 1 to 2 years, and 2 to 3 years) with blood pressure during mid-childhood (6-10 years) and evaluated whether these relations differed by birth size. After accounting for confounders, each additional z-score gain in body mass index during birth to 6 months and 2 to 3 years was associated with 0.81 (0.15, 1.46) and 1.61 (0.33, 2.89) mm Hg higher systolic blood pressure, respectively. Length/height gain was unrelated to mid-childhood blood pressure, and there was no evidence of effect modification by birth size for body mass index or length/height z-score gain. Our findings suggest that more rapid gain in body mass index during the first 6 postnatal months and in the preschool years may lead to higher systolic blood pressure in mid-childhood, regardless of size at birth. Strategies to reduce accrual of excess adiposity during early life may reduce mid-childhood blood pressure, which may also impact adult blood pressure and cardiovascular health.

[Factors associated with abdominal obesity in children]

Objective:

To identify the association of dietary, socioeconomic factors, sedentary behaviors and maternal nutritional status with abdominal obesity in children.

Methods:

A cross-sectional study with household-based survey, in 36 randomly selected census tracts in the city of Santos, SP. 357 families were interviewed and questionnaires and anthropometric measurements were applied in mothers and their 3-10 years-old children. Assessment of abdominal obesity was made by maternal and child's waist circumference measurement; for classification used cut-off points proposed by World Health Organization (1998) and Taylor et al. (2000) were applied. The association between variables was performed by multiple logistic regression analysis.

Results:

30.5% of children had abdominal obesity. Associations with children's and maternal nutritional status and high socioeconomic status were shown in the univariate analysis. In the regression model, children's body mass index for age (OR=93.7; 95%CI 39.3-223.3), female gender (OR=4.1; 95%CI 1.8-9.3) and maternal abdominal obesity (OR=2.7; 95%CI 1.2-6.0) were significantly associated with children's abdominal obesity, regardless of the socioeconomic status.

Conclusions:

Abdominal obesity in children seems to be associated with maternal nutritional status, other indicators of their own nutritional status and female gender. Intervention programs for control of childhood obesity and prevention of metabolic syndrome should consider the interaction of the nutritional status of mothers and their children.

Development of waist circumference percentiles for Japanese children and an examination of their screening utility for childhood metabolic syndrome: a population-based cross-sectional study

BACKGROUND

In Japan, waist circumference (WC) percentiles to screen for childhood metabolic syndrome (MetS) are unavailable. The objectives of this study were to develop WC and WC-to-height ratio (WC/Ht) percentile curves by age and sex for Japanese children, and to test their utility in screening for MetS in children with obesity who are otherwise healthy.

METHODS

The WC and WC/Ht percentiles were developed using the LMS method of summarizing growth standards, which monitors changing skewness (L), medians (M), and coefficients of variation (S) in childhood distributions. A representative dataset was used, which consisted of 3,634 boys and 3,536 girls aged 4.5-12.75 years in Shizuoka prefecture, Japan, between 2010 and 2012. Children who were obese (355 boys and 230 girls) aged 6-12 years from Osaka prefecture, Japan, were screened for childhood MetS using the new percentiles and the International Diabetes Federation's (IDF's) definition of MetS.

RESULTS

The number of participants with certain metabolic abnormalities (high systolic and diastolic blood pressure, and a high level of triglycerides) was significantly higher in boys aged 10-12 years, with a WC ≥ 90th percentile, than among those with a WC < 90th percentile. None of the participants with a WC < 90th percentile exhibited two or more metabolic abnormalities, regardless of their age or sex. Among the participants aged 10-12 years, 11.4 % of boys and 4.4 % of girls with a WC ≥ 90th percentile were diagnosed with MetS.

CONCLUSIONS

The new percentiles may have a certain level of potential to screen Japanese children for childhood MetS in accordance with the IDF definition.

A Western dietary pattern is associated with higher blood pressure in Iranian adolescents

PURPOSE

The dietary determinants of adolescent blood pressure (BP) are not well understood. We determined the association between major dietary patterns and BP in a sample of Iranian adolescents.

METHODS

This cross-sectional study was conducted among a representative sample (n = 557) of Shirazi adolescents aged 12-19 years. Participants' systolic and diastolic BP was measured using a validated oscillometric BP monitor. Usual dietary intakes during the past 12 months were assessed using a valid and reproducible 168-item semiquantitative food frequency questionnaire through face-to-face interviews. Principal component factor analysis was used to identify major dietary patterns based on a set of 25 predefined food groups.

RESULTS

Overall, three major dietary patterns were identified, among which only the Western pattern (abundant in soft drinks, sweets and desserts, salt, mayonnaise, tea and coffee, salty snacks, high-fat dairy products, French fries, and red or processed meats) had a significant association with BP. After adjusting for potential confounders in the analysis of covariance models, multivariable adjusted means of the systolic and mean BP of subjects in the highest tertile of the Western pattern score were significantly higher than those in the lowest tertile (for systolic BP: mean difference 6.9 mmHg, P = 0.001; and for mean BP: mean difference 4.2 mmHg, P = 0.003). A similar but statistically insignificant difference was observed in terms of diastolic BP.

CONCLUSIONS

The findings suggest that a Western dietary pattern is associated with higher BP in Iranian adolescents. However, additional large-scale prospective studies with adequate methodological quality are required to confirm these findings.

Metabolic syndrome among children and adolescents from Southern Italy: contribution from the Calabrian Sierras Community Study (CSCS)

Among 1657 children and adolescents aged 6 to 14 years (787, 47% girls and 870, 53% boys) from primary and secondary schools in a 14-town Southern Italian community, HDL cholesterol (54 ± 15 mg/dl), triglycerides (61 ± 29 mg/dl), blood glucose (78 ± 10 mg/dl), systolic (101 ± 11 mm Hg) and diastolic (62 ± 10 mm Hg) blood pressures, waist circumference (WC) (66 ± 10 cm) and WC/height (0.46 ± 0.006) and triglycerides/HDL cholesterol (1.31 ± 0.99) ratios were measured. The distributions were similar in both genders. Age did not affect triglycerides/HDL cholesterol ratio, whereas there was a slightly positive correlation (p<0.00001) between WC/height and triglycerides/HDL cholesterol ratios. We present individual gender and age specific percentile distributions (as Supplementary materials). Using percentile cut-offs (≤ 10th for HDL cholesterol and ≥ 90th for the other components), there were 183 (11%) children or adolescents with low HDL cholesterol, 162 (9.77%) with high triglycerides, 178 (10.74%) with high blood glucose, 178 (10.74%) with high WC, 244 (20.76%) with high systolic or diastolic BP and 126 (7.6%) with high systolic and diastolic BP. Abnormally high BP was seen in 470 (28.36%) children or adolescents. Using abnormal percentile values of 3 of 5 of its components, metabolic syndrome (MS) was diagnosed in 70 (4.2%) subjects, similarly in both genders. To assess out-of-limit distributions of all 5 individual MS components in children and adolescents gender- and age-distributions derived from local epidemiological data should be used: these distributions are presented and they might now be used both for comparative and applicative purposes at least in Southern Europe.

Percentiles of waist-hip ratio and the relationship with blood pressure among children and adolescents in Shandong, China

BACKGROUND

Anthropometric indices such as waist circumference (WC), waist-to-height ratio (WHtR) and waist-hip ratio (WHR) have been recognized as useful alternatives to visceral fat measurement in epidemiological studies. WHR has been used extensively in adults. However, there are very few published data for WHR among children and adolescents.

AIM

The present study examined the distribution of WHR and the relationship with blood pressure (BP) among children and adolescents in Shandong, PR China.

SUBJECTS AND METHODS

Data for this study were obtained from a large cross-sectional survey of schoolchildren carried out in 2010. A total of 38,822 students (19,456 boys and 19,366 girls) aged 7-17 years participated in this study. WC, Hip circumference (HC), systolic blood pressure (SBP) and diastolic blood pressure (DBP) of all subjects were measured; WHR was calculated as WC divided by HC. Abdominal obesity was defined by previously published WHR references based on Chinese children and adolescents living in Beijing. All subjects were divided into two groups (group 1 with WHR <85th; group 2 with WHR ≥85th) according to the percentiles of WHR and comparisons of the SBP and DBP between the two groups were made.

RESULTS

The WHR levels in Shandong boys and girls were lower than those from German and Pakistani. The overall prevalence of abdominal obesity was 9.53% (95% CI = 9.12-9.95%) for boys and 9.82% (95% CI = 9.40-10.24%) for girls, no statistical differences between the two genders were observed (p > 0.05). In both boys and girls, the Z-scores of SBP and DBP were all significantly lower in group 1 than in group 2 (p < 0.01), indicating that children and adolescents with high WHR tended to have higher BP values.

CONCLUSION

WHR is useful in identifying children and adolescents at risk of developing high BP. These findings, together with the known tracking of BP from adolescence into adulthood, highlight the importance of preventing overweight and obesity among children and adolescents in order to prevent the development of hypertension in adults.