Hypertension in children and adolescents: epidemiology and pathogenesis

Optimal cutoff of the abdominal skinfold thickness (AST) to predict hypertension among Chinese children and adolescents

Previous studies have shown that the correlation between the abdominal skinfold thickness (AST) and hypertension is better than that observed using the body mass index (BMI) or waist-to-height ratio (WHtR). We aimed to explore the optimal cutoff of the AST to predict childhood hypertension. The AST percentiles were calculated based on 215,223 students from the Chinese National Survey on Students' Constitution and Health (CNSSCH) in 2010 using the LMS method. Logistic regression model and Receiver operating characteristic (ROC) curves were used to evaluate the optimal cutoff of the AST to predict hypertension based on a sample of 683 children aged 8-15 years. The prevalence of hypertension was 5.71% (5.45% in boys and 6.01% in girls). The area under the ROC curve [AUC (95% CI)] values of the BMI, WHtR and AST to predict hypertension were 0.62 (0.47-0.77), 0.61 (0.45-0.76), and 0.67 (0.54-0.80) in boys and 0.59 (0.46-0.71), 0.65 (0.50-0.80), and 0.70 (0.57-0.83) in girls, respectively. The AUC value at P₈₅ of AST in boys and that at P₉₀ of AST in girls to predict hypertension were higher than other percentile values of AST. The OR (95% CI) values of the optimal cutoff of the AST associated with hypertension were 2.90 (1.17-7.20) and 4.91 (1.81-13.31) in boys and girls, respectively, and were higher than those associated with overweight/obesity (based on BMI) and abdominal obesity (based on WHtR).The AST was more effectively associated with hypertension than the BMI and WHtR, and the optimal cutoff to predict hypertension was at P₈₅ for boys and P₉₀ for girls.

Relative children's lipid accumulation with hypertension in Chinese children and adolescents

Background

This study aimed to develop a novel indicator associated with hypertension in Chinese children and adolescents, the relative children’s lipid accumulation product (RCLAP).

Methods

A cross-sectional study was conducted in 2018. A total of 683 students aged 8–15 years were recruited via a stratified cluster sampling Methods. Anthropometric indexes (waist circumference (WC), Body mass index (BMI), Waist-height ratio (WHtR), logarithm children LAP (LnCLAP), RCLAP per height (RCLAP-H)) were standardized using a z-score method (standardized variables: SWC, SBMI, SWHtR, SLnCLAP, SRCLAP-H). A logistic regression model was performed to evaluate the association of the above indicators with the outcome of hypertension.

Results

The overall prevalence of hypertension was 5.7% (5.5% in boys, 6.0% in girls). SWC ≥ P₇₅, SBMI ≥ P₇₅, SWHtR ≥ P₇₅, SlnCLAP ≥ P₇₅ and SRCLAP-H ≥ P₇₅ significantly increased risk of hypertension, with odds ratios (OR) of 2.21 (95% confidence interval (CI): 1.13, 4.30), 2.30 (1.18, 4.49), 2.64 (1.35, 5.14), 4.43 (2.28, 8.61), and 4.49 (2.31, 8.71), respectively.

Conclusion

RCLAP is a novel indicator associated with hypertension in Chinese children and adolescents, and it performs better than WC, BMI, WHtR and children LAP.

Hypertension in pediatric patients admitted to inpatient ward at King Abdulaziz Universty Hospital in Saudi Arabia: Prevalence, causes, and outcomes

Background:

The secondary hypertension (HTN) is the predominant form of HTN in pediatrics. Renal diseases and renovascular anomalies are the most commonly reported causes. In this study, we aimed to identify the prevalence, causes, and outcomes of secondary HTN in Saudi Arabia.

Methods:

A retrospective study was conducted among 3,640 pediatric patients aged between 0 and 18 years, admitted to the pediatric nephrology ward at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. The study has been approved by the ethics review committee of King Abdulaziz University.

Results:

Prevalence of secondary HTN due to renal disease was (77.0%). Most of the cases were diagnosed with stage 5 renal disease (78.3%). Small kidney size was frequently diagnosed (n = 29, 11.9%), followed by large kidney size (n = 26, 10.7%). One third of the cases (n = 79, 32.4%) were under control, 49 (20.1%) lost follow-up, and 24 (10.1%) deceased. A total of 61 (33.1%) patients progressed to end-stage renal disease and patientswere managed by different types of treatments.

Conclusion:

The prevalence of secondary HTN due to renal disease is considered to be high in pediatric patients admitted to King Abdulaziz University. Several renal diseases in the renal system are associated with secondary HTN mostly attriubuted to renal malformation. In addition, renal affection, cerebral infarction, bleeding, left ventricular hypertrophy, and valvular lesion are the highest reported complications in our population. Follow-up with ECHO and brain CT is highly recommended in pediatric HTN. Future studies on a larger sample and vigorous follow-up are recommended.

Sedentary time and blood pressure in Australian toddlers: The get-up study longitudinal results

Epidemiological data suggests that the genesis of cardiovascular disease occurs during childhood. Sedentary time (ST) is a main driver of high blood pressure (BP) in adolescents and adults. However, associations between ST and cardiovascular health in young children are uncertain. Prospective associations between ST and BP were assessed among 172 toddlers (88 boys), aged 19.5 ± 3.9 months at baseline, recruited from the GET-UP! Study, Australia and followed over a 12-month period. BP was measured with a digital monitor and z-scores were computed by age and sex for systolic and diastolic BP. Total ST was measured over 7 days using Actigraph accelerometers and expressed over a 24-h period. Multilevel linear regression models were used to assess regression coefficients and standard errors, predicting BP at follow-up from ST at baseline. Analyses controlled for socio-economic status, height, age, gender, group (intervention or control) and zWC at baseline. Adjusted analyses showed that total ST did not predict systolic or diastolic BP (β = 0.0009, p = 0.368 and β = 0.002, p = 0.05, respectively). Most likely, longer follow-up periods might be needed to confirm or rule out our results, as the effects of cumulative ST over time on BP values are prone to manifest later in life and track into adolescence and adulthood.

Combined exposure to lead, cadmium, mercury, and arsenic and kidney health in adolescents age 12-19 in NHANES 2009-2014

BACKGROUND

Occupational and environmental exposures to toxic metals are established risk factors for the development of hypertension and kidney disease in adults. There is some evidence of developmental metal nephrotoxicity in children and from animal studies; however, to our knowledge no previous studies have examined associations between co-exposure to nephrotoxic environmental metals and children's kidney health.

OBJECTIVE

The objective of this study was to assess the association between co-exposure to lead (Pb), cadmium (Cd), mercury (Hg), and arsenic (As), measured in urine and blood, and kidney parameters in US adolescents.

METHODS

We performed a cross-sectional analysis of a subsample of 2709 children aged 12-19 participating in the National Health and Nutrition Examination Survey (NHANES) between 2009 and 2014. We analyzed urine levels of 4 nephrotoxic metals selected a priori (As, Cd, Pb and Hg), U_mix, and 3 nephrotoxic metals in blood (Cd, Pb, and Hg), B_mix, using a weighted quantile sum (WQS) approach. We applied WQS regression to analyze the association of B_mix and U_mix with estimated glomerular filtration rate (eGFR), serum uric acid (SUA), urine albumin, blood urea nitrogen (BUN), and systolic blood pressure (SBP), adjusting for sex, race/ethnicity, age, head of household's education level, height, BMI, serum cotinine, and NHANES cohort year. U_mix and urine albumin models were also adjusted for urine creatinine, and B_mix models were also adjusted for fish consumption. Subanalyses included stratification by sex and an arsenic-only model including six speciated forms of As measured in urine.

RESULTS

In WQS regression models, each decile increase of U_mix was associated with 1.6% (95% CI: 0.5, 2.8) higher BUN, 1.4% (95% CI: 0.7, 2.0) higher eGFR, and 7.6% (95% CI: 2.4, 13.1) higher urine albumin. The association between U_mix and BUN was primarily driven by As (72%), while the association with eGFR was driven by Hg (61%), and Cd (17%), and the association with urine albumin was driven by Cd (37%), Hg (33%), and Pb (25%). There was no significant relationship between U_mix and SUA or SBP. In WQS models using the combined blood metals, B_mix, each decile increase of B_mix was associated with 0.6% (95% CI: 0.0, 1.3) higher SUA; this association was driven by Pb (43%), Hg (33%), and Cd (24%) and was marginally significant (p = 0.05). No associations were observed between B_mix and urine albumin, eGFR, BUN, or SBP.

CONCLUSIONS

The findings suggest metals including As, Pb, Hg, Cd and their combinations may affect renal parameters, although potential reverse causation cannot be ruled out due to the cross-sectional study design. Implications of early life low-level exposure to multiple metals on kidney function may have far-reaching consequences later in life in the development of hypertension, kidney disease, and renal dysfunction. Longitudinal studies should further evaluate these relationships.

Phthalate exposure as a risk factor for hypertension

Phthalates are ubiquitous in environment. Hypertension is a major risk factor for cardiovascular diseases. Phthalate exposure is associated with hypertension in multiple studies. This review aims to summarize the scientific literature on associations between phthalate exposure and hypertension and discuss the mechanisms in the relationship. We identified and reviewed original articles published to March 2018, using PubMed and Web of Science to search the terms "phthalate(s)," "phthalic acid," "blood pressure," "high blood pressure," "hypertension," "prehypertension," and "cardiovascular disease." Findings were summarized based on the relevance to the themes, including presentation of main phthalates and their major metabolites as well as associations of phthalate exposure with blood pressure in epidemiological and experimental studies. We identified ten population-based investigations and five toxicological experiments. Epidemiological data underscored a possible correlation between phthalate exposure and hypertension in adults, whereas individual study in children stands on the opposite. Experimental studies mainly targeted the increasing effect of phthalates on blood pressure. This review suggested some underlying mechanisms of phthalate-associated hypertension. Considering the current evidence, phthalate might be risk factors of hypertension. However, the effect of phthalate exposure in early life on blood pressure in later life or adulthood is still unclear. Well-designed longitudinal and molecular mechanism studies are indispensable.

Whole blood viscosity and cerebral blood flow velocities in obese hypertensive or obese normotensive adolescents

BACKGROUND

Obesity affects all major organ systems and leads to increased morbidity and mortality. Whole blood viscosity is an important independent regulator of cerebral blood flow. The aim of the present study was to evaluate the effect of whole blood viscosity on cerebral artery blood flow velocities using transcranial Doppler ultrasound in pediatric patients with obesity compared to healthy controls and analyze the effect of whole blood viscosity and blood pressure status to the cerebral artery blood flow velocities.

METHODS

Sixty patients with obesity diagnosed according to their body mass index (BMI) percentiles aged 13-18 years old were prospectively enrolled. They were grouped as hypertensive or normotensive according to their ambulatory blood pressure monitoring. Whole blood viscosity and middle cerebral artery velocities by transcranial Doppler ultrasound were studied and compared to 20 healthy same aged controls.

RESULTS

Whole blood viscosity values in hypertensive (0.0619±0.0077 poise) and normotensive (0.0607±0.0071 poise) groups were higher than controls (0.0616±0.0064 poise), with no significance. Middle cerebral artery blood flow velocities were higher in the obese hypertensive (73.9±15.0 cm/s) and obese normotensive groups (75.2±13.5 cm/s) than controls (66.4±11.5 cm/s), but with no statistical significance.

CONCLUSIONS

Physiological changes in blood viscosity and changes in blood pressure did not seem to have any direct effect on cerebral blood flow velocities, the reason might be that the cerebral circulation is capable of adaptively modulating itself to changes to maintain a uniform cerebral blood flow.

Sports Practices and Cardiovascular Risk in Teenagers

Background

Cardiovascular diseases are the leading cause of deaths in the world, and many events could be prevented by healthy life habits.

Objectives

To compare the occurrence of cardiovascular risk factors in adolescents enrolled at public schools in the city of Rio de Janeiro, including a renowned school for sport practices.

Methods

Cross-sectional study, convenience sampling of 422 students enrolled at the Experimental Olympic Gymnasium (EOG) and at Figueiredo Pimentel School (FP). Using descriptive analyses, continuous variables were expressed as mean and standard deviation or median and interquartile ranges, and the Student's t-test or the chi-square test, respectively, was used for comparisons. The sports were classified according to the metabolic equivalent of task (MET) (below or above 5).

Results

We included 274 students enrolled at the EOG and 148 at FP. Mean age was similar between schools -12.5 ± 1.6 years at FP and 12.6 ± 0.9 at the EOG; 65.5% of the students at FP and 43.8% of the students at the EOG were female (p < 0.01). Significant differences in the prevalence of hypertension (20% vs. 6.3%, p < 0.01) and borderline cholesterol levels (27.7% vs. 17.3%, p = 0.01) were found between FP and EOG students, respectively.

Conclusion

High prevalence of hypertension, overweight/obesity and altered blood lipid profile was found in this group of adolescents. Regular sports training program combined with little influence of their eating habits outside school may contribute to a better metabolic profile and reduction in cardiovascular risk factors in students. Public health measures are also need.

Prevalence of hypertension and prehypertension in children and adolescents with intellectual disability in southeastern Poland

BACKGROUND

There is insufficient information on the prevalence of hypertension (HPT) among children and adolescents with ID.

AIM

The aim of this study was to determine the prevalence of HPT in children and adolescents with ID in comparison with the control group, which accounted for children and adolescents without ID.

METHODS

The study included 568 students with ID, aged from 7 to 18, attending special education institutions in southeastern Poland. The control group consisted of 568 students (matched to the study group for age and gender) without ID, attending randomly selected elementary and secondary schools located in the same area. Blood pressure was measured in compliance with the European Society of Hypertension recommendations.

RESULTS

The overall prevalence of HPT and pre-HPT in children and adolescents with ID were 18.5 and 20.6% respectively. Prevalence of HPT and pre-HPT in children and adolescents without ID were 5.8 and 18.5% respectively. Children and adolescents with a higher level of ID were found to be at a greater risk of HPT. An excessive body mass and older age were predisposing factors to a significantly higher prevalence of HPT in children and adolescents with ID.

CONCLUSION

The prevalence of HPT among students with ID was more than three times higher than in the general population. The level of ID, age, sex and body mass significantly correlated with HPT in the study group.

Association Between Serum Levels of Uric Acid and Blood Pressure Tracking in Childhood

BACKGROUND

Recent studies suggest that high levels of serum uric acid of very early life are a result of the in-utero environment and may lead to elevated blood pressure (BP) in adulthood. However, serum uric acid levels can change throughout life. We investigated the effect of serum uric acid levels in childhood on the BP tracking and analysed BP according to changes in serum uric acid levels in early life.

METHODS

A total of 449 children from the Ewha Birth and Growth Cohort study underwent at least 2 follow-up examinations. Data were collected across 3 check-up cycles. Serum uric acid levels, BP, and anthropometric characteristics were assessed at 3, 5, and 7 years of age.

RESULTS

Children with a serum uric acid level higher than the median values had significantly increased systolic BP (SBP) and diastolic BP at 3 years of age. Baseline serum uric acid levels measured at 3 years of age, significantly affected subsequent BP in the sex and body mass index adjusted longitudinal data analysis (P < 0.05). Considering the changing pattern of serum uric acid over time, subjects with high uric acid levels at both 3 and 5 years of age had the highest SBP at 7 years of age.

CONCLUSIONS

These findings suggest the importance of maintaining an adequate level of serum uric acids from the early life. Appropriate monitoring and intervention of uric acid levels in a high-risk group can reduce the risk of a future increased BP.

Visceral fat enhances blood pressure reactivity to physical but not mental challenges in male adolescents

BACKGROUND

Excess visceral fat is a major risk factor for hypertension. Enhanced blood pressure (BP) reactivity and delayed BP recovery from physical and mental challenges predict future hypertension.

OBJECTIVES

Determine whether visceral fat is associated with higher BP reactivity and delayed BP recovery from physical and mental challenges during adolescence.

METHODS

In a community-based sample of 283 male and 308 female adolescents, we measured visceral fat with magnetic resonance imaging, total body fat with bioimpedance, and beat-by-beat BP with a Finometer at rest and during physical (10-min standing) and mental (2-min math stress) challenges.

RESULTS

Males vs. females showed greater BP reactivity and no differences in BP recovery from either type of challenges. Visceral fat was positively associated with BP reactivity to standing up only and in males only (+8.4 ± 3.6 mmHg per 1 log cm(3) of visceral fat, P = 0.008), and this association was independent of total body fat. No association was seen between visceral fat and BP recovery from either type of challenge in either sex. All these associations were independent of age, puberty stage, height and initial BP.

CONCLUSIONS

Adolescent males vs. females demonstrate greater BP reactivity but similar BP recovery from physical and mental challenges. Excess visceral fat enhances BP reactivity to physical but not mental challenges in males only.

The relationship between blood pressure, anthropometric indices and metabolic profile in adolescents: a cross sectional study

OBJECTIVE

To investigate the relationship between blood pressure, anthropometric indices and metabolic profile in adolescents.

METHODS

The present cross sectional study was conducted in 1005, 12-y-old junior students referred to 15 urban health centers of Rasht. Samples were recruited randomly and data were collected in a form which consisted of demographic characteristics, history of disease in samples and their immediate families, birth weight, physical examination and clinical examination including height, weight, blood pressure and body mass index. Also, metabolic profiles including fasting blood sugar (FBS), blood sugar (BS), cholesterol, and triglyceride (TG), low density lipoprotein (LDL), high-density lipoprotein (HDL) and insulin levels were measured. Data were analyzed in SPSS software, by descriptive and analytic statistics and p value 0.05 was considered statistically significant.

RESULTS

Eight hundred fifty nine adolescents consisting of 550 (64 %) boys and 309 (34 %) girls participated in this study; 11.4 % (84/739 cases) of the participants had hypertension. The strongest correlation was seen between systolic blood pressure and weight, waist or hip circumferences and insulin levels. Also, FBS had very weak correlation with blood pressure.

CONCLUSIONS

Thus, weight, waist and hip circumferences, insulin levels, high TG and low HDL have been indicated as the strongest correlating factors for high blood pressure.Thus, these factors should be investigated in high risk children and followed in hypertensive child to monitor cardiometabolic risk factors.

Hydrogen sulfide upregulates KATP channel expression in vascular smooth muscle cells of spontaneously hypertensive rats

The study was designed to investigate whether H2S could upregulate expression of KATP channels in vascular smooth muscle cells (VSMCs), and by this mechanism enhances vasorelaxation in spontaneously hypertensive rats (SHR). Blood pressure, vascular structure, and vasorelaxation were analyzed. Plasma H2S was detected using polarographic sensor. SUR2B and Kir6.1 expressions were detected in VSMCs of SHR and in A7r5 cells as well as primarily cultured ASMCs using real-time PCR, western blot, immunofluorescence, and confocal imaging. Nuclear translocation of forkhead transcription factors FOXO1 and FOXO3a in ASMCs was detected using laser confocal microscopy, and their binding activity with SUR2B and Kir6.1 promoters was examined by chromatin immunoprecipitation. SHR developed hypertension at 18 weeks. They showed downregulated vascular SUR2B and Kir6.1 expressions in association with a decreased plasma H2S level. H2S donor, however, could upregulate vascular SUR2B and Kir6.1 expressions, causing a left shift of the vasorelaxation curve to pinacidil and lowered tail artery pressure in the SHR. Also, H2S antagonized endothelin-1 (ET-1)-inhibited KATP expression in A7r5 cells and cultured ASMCs. Mechanistically, H2S inhibited ET-1-stimulated p-FOXO1 and p-FOXO3a expressions (inactivated forms), but increased their nuclear translocation and the ET-1-inhibited binding of FOXO1 and FOXO3a with Kir6.1 and SUR2B promoters in ASMCs. Hence, H2S promotes vasorelaxation of SHR, at least in part, through upregulating the expression of KATP subunits by inhibiting phosphorylation of FOXO1 and FOXO3a, and stimulating FOXO1 and FOXO3a nuclear translocation and their binding activity with SUR2B and Kir6.1 promoters.

KEY MESSAGES

H2S increased vascular SUR2B and Kir6.1 expression of SHR, promoting vasorelaxation. H2S antagonized ET-1-inhibited KATP expression in A7r5 cells and cultured ASMCs. H2S inhibited ET-1-induced FOXO1 and FOXO3a phosphorylation in ASMCs. H2S promoted FOXO1 and FOXO3a nuclear translocation and binding with target gene promoters.

High blood pressure and its association with body weight among children and adolescents in the United Arab Emirates

Objectives

To estimate the prevalence of high blood pressure (BP) and its relationship with obesity among children and adolescents.

Methodology/Principal Findings

In this cross-sectional population (Emirati) representative study, we invited a random sample of 1600 students (grades 1–12) attending 23 out of all 246 schools in the Emirate of Abu Dhabi, United Arab Emirates. But analysis was restricted to Emirati nationals aged 6–17 years. We measured BP, height, weight, waist circumferences (WC), and calculated body mass index (BMI) by standard methods. BP levels ≥90^th percentile but <95^th percentile and ≥ 95^th for age, sex, and height (CDC percentiles) were classified as pre-hypertension (pre-HTN) and hypertension (HTN), respectively. Associations between BP, age, BMI, WC, and sex, were investigated by (multiple) linear regression methods. A total of 999 (47% girls) students provided complete results. The prevalence of pre-HTN was 10.5% and 11.4% and the prevalence of HTN was 15.4% and 17.8% among boys and girls, respectively. The prevalence of systolic/diastolic HTN was 14.4%/2.5% and 14.8/7.4% among boys and girls, respectively. BMI CDC percentile was positively correlated with WC percentile (r = 0.734, p<0.01), and both systolic (r = 0.34, p<0.001) and diastolic (r = 0.21, p<0.001) standardized BP. WC percentile was less strongly correlated with standardized SBP (r = 0.255, p<0.01) and DBP (r = 0.175, p<0.01) than BMI.

Conclusions/Significance

The prevalence of elevated BP, notably systolic was significantly high among the Emirati children and adolescents in Abu Dhabi. High BP was strongly related to body weight, and appears more strongly associated with BMI than WC. Further studies are required to investigate the impact of childhood obesity on HTN.

A 5-year hospital prevalence of child and adolescent psychiatric disorders from central India

OBJECTIVE

To examine the 5-year hospital prevalence of child and adolescent mental disorders from Central India.

METHODS

Using systemic random sampling method, of the 4410 families screened, 4278 children (607 aged 0 to 3 y and 3671 between 4 to 16 y) attending outpatient services of department of pediatrics at the tertiary rural hospital from June 2006 through December 2010 were evaluated. Standardized appropriate psychometric tools were used for both groups. Diagnostic interviews were administered and DSM-IV diagnoses were determined by consensus between two psychiatrists. A comprehensive hospital registration system provided the denominator.

RESULTS

Of the 4410 families screened, 4278 (97 %) of the subjects completed interviews. The overall prevalence of psychiatric disorders was found to be 20.8 %. Most common psychiatric disorders in group A were mental retardation (5.6 %) followed by epilepsy (2 %) whereas in group B, depressive disorder (3.73 %) were followed by non-organic enuresis (2.18 %) and ADHD (1.7 %). Eighty one percent of the parents from group A and 83 % of parents from group B of the children affected with psychiatric disorders and neurobehavioral problems had reported that they have had never thought of taking psychiatric consultation for their children.

CONCLUSIONS

The results of the study have helped in bridging and supporting the propositions in child epidemiology in India and also have implications for clinical training and practice.