Determinants of cardiac involvement in children and adolescents with essential hypertension

Exome sequencing implicates ancestry-related Mendelian variation at SYNE1 in childhood-onset essential hypertension

Childhood-onset essential hypertension (COEH) is an uncommon form of hypertension that manifests in childhood or adolescence and, in the United States, disproportionately affects children of African ancestry. The etiology of COEH is unknown, but its childhood onset, low prevalence, high heritability, and skewed ancestral demography suggest the potential to identify rare genetic variation segregating in a Mendelian manner among affected individuals and thereby implicate genes important to disease pathogenesis. However, no COEH genes have been reported to date. Here, we identify recessive segregation of rare and putatively damaging missense variation in the spectrin domain of spectrin repeat containing nuclear envelope protein 1 (SYNE1), a cardiovascular candidate gene, in 3 of 16 families with early-onset COEH without an antecedent family history. By leveraging exome sequence data from an additional 48 COEH families, 1,700 in-house trios, and publicly available data sets, we demonstrate that compound heterozygous SYNE1 variation in these COEH individuals occurred more often than expected by chance and that this class of biallelic rare variation was significantly enriched among individuals of African genetic ancestry. Using in vitro shRNA knockdown of SYNE1, we show that reduced SYNE1 expression resulted in a substantial decrease in the elasticity of smooth muscle vascular cells that could be rescued by pharmacological inhibition of the downstream RhoA/Rho-associated protein kinase pathway. These results provide insights into the molecular genetics and underlying pathophysiology of COEH and suggest a role for precision therapeutics in the future.

Pediatric Hypertension: A Condition That Matters

Systemic hypertension has been considered mainly as an adult health issue for a long time, but it is now being increasingly acknowledged as a significant problem also among pediatric patients. The frequency of pediatric hypertension has grown mostly because of increases in childhood obesity and sedentary lifestyles, but secondary forms of hypertension play a role as well. Considering that unaddressed hypertension during childhood can result in enduring cardiovascular complications, timely identification and intervention are essential. Strategies for addressing this disease encompass not only lifestyle adjustments, but also the use of medications when needed. Lifestyle modifications entail encouraging a nutritious diet, consistent physical activity, and the maintenance of a healthy weight. Moreover, educating both children and their caregivers about monitoring blood pressure at home can aid in long-term management. Thus, the aim of this review is to discuss the etiologies, classification, and principles of the treatment of hypertension in pediatric patients.

Left ventricle mass index in paediatric intensive care unit acquired hypertension

BACKGROUND

Hypertension acquired in paediatric critical patients is a recognised challenge, with variable reported frequency. Pain, agitation, and/or medications such as beta stimulants and corticosteroids are well-known risk factors. Sympathomimetics in septic patients can cause high blood pressure, especially with unobserved haemodynamic monitors. Beyond haemodynamic factors, several endocrinal-metabolic factors - including catecholamines, insulin, renin, angiotensin, the aldosterone system, and sodium consumption - may contribute to the left ventricular growth. It is well known that the sympathetic tone has a trophic effect on the heart muscle.

METHOD

A prospective cohort study was conducted during the year 2021. The children were divided into two groups: those who were critically ill with paediatric intensive care unit-acquired hypertension (n = 59) and those without paediatric intensive care unit-acquired hypertension (n = 62). We used the American Academy of Pediatrics' 2017 definition of hypertension to diagnose paediatric intensive care unit-acquired hypertension. Measurement of cardiac output and systemic vascular resistance was performed by cardiometry. Left ventricular myocardial performance and left ventricular mass index were measured by bedside echocardiography at the onset of hypertension diagnosis.

RESULTS

Critically ill children with acquired hypertension had a higher cardiac index (p = 0.0001), systemic vascular resistance index (<0.0001), myocardial performance (0.037), and left ventricular mass index (0.009). The longer duration of stay observed in the hypertension group had no observable effect on mortality (<0.0001).

CONCLUSION

Both myocardial performance and left ventricle mass index increased in critically ill children with paediatric intensive care unit-acquired hypertension.

Association of Childhood Blood Pressure with Left Atrial Size and Function: Study of High Blood Pressure in Pediatrics-Adult Hypertension in Youth (SHIP AHOY)

OBJECTIVE(S)

To evaluate the cross-sectional association of cardiovascular disease risk factors with left atrial (LA) size and function among healthy youth, aged 11-18 years, with a wide range of blood pressures (BPs).

STUDY DESIGN

Echocardiographic images of youth enrolled in the Study of High Blood Pressure in Pediatrics: Adult Hypertension Onset in Youth study were analyzed for LA measurements. The association of casual BP, ambulatory BP, and other cardiovascular disease risk factors with LA size and function were determined using descriptive statistics and multivariable regression. Regression models adjusting for age, sex, race, and body mass index z score determined the independent association between ambulatory systolic BP indices (mean systolic BP/50th %ile systolic BP) and BP phenotypes with LA outcomes while exploratory analyses investigated for additional predictors of LA outcomes.

RESULTS

The study population consisted of 347 youth: median age 15.7 years, 60% male and 40% non-White. Greater-risk casual systolic BP groups had worse cardiometabolic profiles but no differences in LA size and function. Each 0.1 increase in ambulatory systolic BP day or night index was associated with a 9.9 mL/m2 increase in LA volume/body surface area (LAV/BSA; 95th% CI 2.8-17.0, P = .006) and a 6.8 mL/m2 increase in LAV/BSA (95th% CI 0.8-12.8, P = .03), respectively. Ambulatory hypertension was associated with greater odds of abnormal LAV/BSA, defined as >75th %ile (2014 ambulatory BP monitoring criteria: OR 3.2 [95th% CI 1.4-7.2; P = .002]; 2022 ambulatory BP monitoring criteria: OR 2.1 [95th% CI 1.0-4.1; P = .008]).

CONCLUSIONS

Increasing ambulatory systolic BP and ambulatory hypertension are independently associated with LAV/BSA.

Dietary sodium intake and sodium load is associated with arterial stiffness in children and young adults

OBJECTIVE

The aim of this study was to examine the association of sodium intake (g/day) and sodium load (Na-L; mg/kcal/day) on arterial stiffness in youth.

METHODS

A cross-sectional analysis of 723 youth enrolled in a study evaluating the cardiovascular effects of obesity and type 2 diabetes mellitus (T2DM). Three measures of arterial stiffness were evaluated: brachial distensibility (BrachD), carotid-femoral pulse wave velocity (PWVcf) and augmentation index (AIx). Three-day diet histories yielded mean daily sodium and calorie intake. Youth were divided into Na-L tertiles: Low (≤1.67 mg/kcal per day); Medium (1.68--1.98 mg/kcal per day) and High (>1.98 mg/kcal per day). General linear models adjusting for demographics, % body fat, T2DM and SBP z-score evaluated the independent association of Na-L with arterial stiffness.

RESULTS

Mean age was 17.9 years (10-24 years), 35% male, 59% nonwhite and 31% T2DM. Mean (±standard deviation) dietary intake was calories = 2074 (±797) kcal/day; Na = 3.793 (±1567) g/day; Na- = 1.86 (±0.753) mg/kcal per day. With higher levels of dietary Na intake and Na-L, measures of arterial stiffness worsened: BrachD decreased (Na intake: beta = -0.09, P = 0.003; Na-L: beta = -0.28, P < 0.0001), PWVcf increased (Na intake: beta = 0.07, P = 0.007; Na-L: beta = 0.21, P < 0.0001) but AIx did not change (Na intake: beta = -0.4, P = 0.2; Na-L: beta = 0.89, P = 0.11). In multivariable analysis, High Na-L was independently associated with BrachD, PWVcf and AIx (P < 0.05 for all), with age modifying the association of High Na-L with PWVcf and AIx.

CONCLUSION

Sodium intake and load are associated with arterial stiffness, a preclinical measure of CVD, among a paediatric population. Paediatricians should stress healthy dietary choices to reduce accelerated vascular ageing.

The Correlation Between ABPM Parameters and Left Ventricular Hypertrophy in Pediatric Essential Hypertension

OBJECTIVE

To explore the association of dipping pattern and blood pressure load with left ventricular hypertrophy (LVH) in pediatric essential hypertension.

MATERIALS AND METHODS

Through an echocardiography monitor and an ambulatory blood pressure monitor of 425 children and adolescents diagnosed with essential hypertension with no treatment received, we identified 140 cases of LVH. Grouping patients according to LVH (LVH, N = 140; n-LVH, N = 285), we further evaluated their ambulatory blood pressure monitoring (ABPM) parameters by comparing dipping patterns between groups. A multivariable logistic regression analysis was used to determine the effect of blood pressure load on LVH.

RESULTS

No significant difference was found in systolic or diastolic blood pressure dipping patterns between groups (P = 0.161, P = 0.139). However, compared to the n-LVH group, the LVH group presented significant elevated nighttime systolic blood pressure (SBP) (P < 0.05), while nighttime DBP remained stable (P = 0.391), resulting in higher daytime and nighttime SBP loads, higher nighttime DBP load, and higher 24-h SBP load (P < 0.05). Notably, our multivariable logistic regression has shown that this trend of 24-h SBP load acts independently as a critical risk factor for LVH.

CONCLUSION

Collectively, we observed a correlation between BP load and LVH in pediatric hypertension. Our data demonstrated that SBP load has a more significant weight in LVH progression, and 24-h SBP load, in particular, acts as a critical early prognostic parameter for LVH in pediatric hypertension.

Left Ventricular Measurements and Strain in Pediatric Patients Evaluated for Systemic Hypertension and the Effect of Adequate Anti-hypertensive Treatment

Pediatric hypertension (HTN) is an epidemic that is associated with HTN in adulthood and adverse cardiovascular outcomes. We hypothesized that children with HTN would have left ventricular (LV) hypertrophy and abnormal LV global longitudinal strain (GLS) on echocardiogram and that these values would differ by weight, race, and HTN treatment. Data were collected from first visits to the HTN Program from 12/2011 to 9/2018, excluding patients with cardiac disease or heart transplantation. LV measurements including LV mass index (LVMI), LV GLS, and diastolic indices were compared between groups. Multivariable logistic regression was used to identify risk factors for an abnormal LVMI. There were 212 patients with an interquartile age range of 13-18 years. On univariate analysis, LVMI was higher in hypertensive, obese, and African American patients. LV strain was less negative in obese and African American patients. Adequately treated patients with HTN had a higher LVMI and a higher E/e' ratio compared to patients with no HTN. On multivariate analysis, only obesity was associated with an LVMI ≥ 95th percentile (OR 2.9, 95% CI 1.4, 5.8). LVMI is higher in hypertensive, obese, and African American patients; however, in the multivariate analysis, obesity was the only independent risk factor for an abnormal LVMI. LVMI was still higher in those adequately treated for HTN compared to patients without HTN, possibly due to concomitant obesity. Future studies should focus on subclinical changes in LV performance seen in obese and hypertensive patients and the impact on long-term health.

Risk of hypertension in school-aged children undergoing a long-term community-based lifestyle intervention: Tehran Lipid and Glucose Study

Childhood hypertension which increases the risk of cardiovascular diseases in adulthood is becoming more prevalent. For the first time in the Middle-East region, this study aimed to assess the long-term effectiveness of a community-based lifestyle intervention on the incidence of hypertension in school-aged children during 16 years of follow-up. This study was conducted within the framework of the Tehran Lipid and Glucose Study (TLGS). Participants were 2080 children aged 8-18 years with normal blood pressure who were under the coverage of three health care centers selected using multistage cluster random sampling method. One of the health care centers far from the other two was selected for implementing lifestyle intervention (1053 children, 48.2% boys). Triennial examinations were conducted, and survival Cox models were used to assess intervention effects on the incidence of hypertension in boys and girls. Crude incidence rates (per 1000 person-years) of hypertension were 8.11, 3.7, and 5.8 among boys, girls, and the total sample, respectively. Our results showed that HTN has occurred significantly less (P = 0.025) in the intervention group than in the control group, only in female participants. These results remained significant even after adjusting for individuals' and parental characteristics (P = 0.033). Although the risk of hypertension in boys was more than twice that observed in girls, the effectiveness of the recent community-based healthy lifestyle intervention was observed only in girls and not in boys. Further studies are needed to understand gender differences in promoting the effectiveness of similar future programs. The TLGS is registered at Iran Registry for Clinical Trials, a WHO primary registry (http://irct.ir; IRCTID: IRCT138705301058N1).

Left Ventricular Diastolic Dysfunction Among Youth with Obesity and History of Elevated Blood Pressure

OBJECTIVE

To assess prevalence of and factors associated with left ventricular diastolic dysfunction (LVDD) in youth with obesity and elevated blood pressure (BP).

STUDY DESIGN

This was a cross-sectional analysis of baseline and follow-up visits of 83 youth, 5-21 years, evaluated for overweight/obesity and elevated BP in a multidisciplinary clinic. LVDD was defined according to established adult criteria (LVDD_adult; E/A < 1, E/e' > 14, or e'/a' < 0.8) and pediatric criteria (LVDD_peds; E/A <10th percentile, E/e' >99th percentile, or e'/a' <1st percentile) based on data from 103 age-sex matched healthy controls. Baseline factors associated with LVDD_peds were examined using Wilcoxon rank sum and χ² tests. Multiple logistic regression analyses using generalized estimating equations to account for repeated measures evaluated the associations of adiposity and BP with LVDD_peds.

RESULTS

The prevalence of LVDD ranged from 1.2% to 2.7% when we used adult criteria and 19% to 28% when we used pediatric criteria. Those with LVDD_peds were older, predominantly male, and non-African American and had greater weight, BP, BP medication use, and non-high-density lipoprotein cholesterol than those without LVDD_peds. Diastolic BP z score was associated with LVDD_peds by E/A (OR 1.95, 95% CI 1.15-3.32, P = .014) after we adjusted for age, sex, race, BP medications, and body mass index z score.

CONCLUSIONS

LVDD was present in a substantial proportion of youth with overweight/obesity and elevated BP using pediatric criteria. Those with LVDD_peds had significantly greater measures of adiposity and BP compared with those without LVDD_peds, and diastolic BP z score was an independent predictor of LVDD_peds by E/A. These data emphasize the importance of prevention and treatment of cardiovascular disease risk factors in childhood.

Association of Urinary Sodium Excretion and Left Ventricular Hypertrophy in People With Type 2 Diabetes Mellitus: A Cross-Sectional Study

BACKGROUND

It has been well documented that left ventricular hypertrophy (LVH) is highly associated with the incidence of cardiovascular disease (CVD). Evidence indicated that high sodium intake was closely related with LVH in general population. However, information is not available regarding the association between urinary sodium excretion and LVH in patients with type 2 diabetes mellitus (T2DM). This study aimed to explore the association between urinary sodium excretion and LVH in patients with T2DM.

METHODS

This cross-sectional analysis included baseline data from 1,556 individuals with T2DM enrolled in the NanFang Prospective Diabetes Study (NFPDS). Urinary sodium excretion levels were measured from 24-hour urine samples of inpatients and morning fasting urine samples of outpatients. Left ventricular dimensions were assessed by echocardiography. The associations between urinary sodium excretion and the risks of cardiovascular events, LVH and left ventricular mass index (LVMI) were examined using linear regression analysis, logistic regression and restricted cubic splines (RCS).

RESULTS

Urinary sodium excretion levels were positively associated with cardiometabolic risk factors, including systolic blood pressure, body mass index, waist circumference and LVMI (All P<0.001). Odds ratios of the highest quartile of urinary sodium excretion compared with the lowest quartile were 1.80 (95% CI, 1.28-2.54; P=0.001) for LVH and 1.77 (95% CI, 1.06-2.94; P=0.028) for CVD, after adjusted for demographics, lifestyle risk factors and cardiovascular risk factors. Multivariable-adjusted RCS analysis of the association between urinary sodium excretion and LVMI showed a significant association (P=0.001) and lacked evidence of a nonlinear association (P=0.406).

CONCLUSION

This study indicated that high urinary sodium excretion was independently associated with increased risk of LVH and CVD in patients with T2DM, suggesting that control of sodium intake may be valuable for the prevention of diabetic cardiovascular complications.

Factors Associated with Primary Hypertension in Pediatric Patients: An Up-to-Date

BACKGROUND

Arterial hypertension in children is considered a common alteration nowadays, mainly because obesity is a growing worldwide problem closely related to increased blood pressure. Childhood hypertension can be classified as primary or secondary, depending on the etiology. Primary or essential hypertension still has its pathophysiology not fully elucidated, and there is no consensus in the literature on most underlying mechanisms. In this review, genetic and environmental factors, including sodium and potassium intake, socioeconomic status, ethnicity, family structure, obesity, sedentary lifestyle, prematurity and low birth weight, prenatal and postnatal exposures are highlighted.

OBJECTIVE

The present study aimed to perform an update on primary hypertension in childhood, providing clinicians and researchers an overview of the current state of the literature regarding the influence of genetic and environmental factors.

METHODS

This integrative review searched for articles on genetic and environmental factors related to primary hypertension in pediatric patients. The databases evaluated were PubMed and Scopus.

RESULTS

The studies have provided insights regarding many genetic and environmental factors, in addition to their association with the pathophysiology of primary hypertension in childhood. Findings corroborated the idea that primary hypertension is a multifactorial disease. Further studies in the pediatric population are needed to elucidate the underlying mechanisms.

CONCLUSION

The study of primary hypertension in pediatrics has utmost importance for the adoption of preventive measures and the development of more efficient treatments, therefore reducing childhood morbidity and the incidence of cardiovascular diseases and other health consequences later in life.

Trends in Sodium Intake in Children and Adolescents in the US and the Impact of US Department of Agriculture Guidelines: NHANES 2003-2016

OBJECTIVE

To examine trends in sodium intake and the impact of nutritional guidelines in the US pediatric population.

STUDY DESIGN

Sodium intake data collected between 2003 and 2016 in the US National Health and Nutrition Examination Surveys (NHANES) were analyzed. Trends in intake for individuals aged 4-17 years and subgroups based on age, sex, and race and ethnicity were examined. Adherence to US Department of Agriculture guidelines was assessed.

RESULTS

A total of 16 013 individuals (50.6% male) were included in the analysis. The median sodium intake was 2840 mg/day (95% CI, 2805-2875 mg/day), decreasing from 2912 mg/day (95% CI 2848-2961 mg/day) in 2003-2004 to 2787 mg/day (95% CI, 2677-2867 mg/day) in 2015-2016 (P = .005). Intake increased with age (2507 mg/day for individuals aged 4-8, 2934 mg/day for those aged 9-13 years, and 3124 mg/day for those aged 14-17 years; P < .001) and was greater in males than in females (3053 mg/day vs 2624 mg/day; P < .001). Caucasians, Hispanics, and African Americans consumed 2860, 2733, and 2880 mg/day, respectively (P < .001). Population adherence to US Department of Agriculture recommendations was 25.0% in 2003-2010 and 25.5% in 2011-2016 (P = .677). No age, sex, or racial/ethnicity subgroup had an adherence rate >30% after implementation of pediatric guidelines in 2010.

CONCLUSIONS

Sodium intake remains elevated in all pediatric population segments, and guideline adherence is poor. A greater effort to reduce sodium consumption is needed to mitigate future cardiovascular disease risk.

Evidence Gaps in the Identification and Treatment of Hypertension in Children

The ultimate goal of recognizing and treating hypertension in childhood is to prevent target-organ damage during childhood and to reduce the risk of adulthood cardiovascular disease. The quality of evidence to guide blood pressure management in children is lower than in adult medicine, yet some common findings support clinical practice recommendations. Oscillometric devices are increasingly replacing manual blood pressure measurements, but evidence shows that readings are not equivalent between the 2 methods. In addition, multiple blood pressure readings are needed before diagnosing a child with hypertension, but the optimal number and timing are still being determined. The recent American Academy of Pediatrics blood pressure guideline has revised the normative data tables and included threshold blood pressure limits which seem to identify children with higher cardiovascular risks. Threshold limits vary between guidelines, and the most accurate threshold has yet to be determined. Lifestyle modifications are a cornerstone of hypertension management, but the optimal diet and physical activity changes for beneficial effect are not known. When pharmacotherapy is needed, physicians have used drugs from all antihypertensive classes in children, yet only a few classes have been systematically studied. The long-term cardiovascular consequences of elevated blood pressure during childhood are under investigation and it seems that the lower the childhood blood pressure the better and that the rate of change during childhood is predictive of adulthood disease. With much still to learn, this article summarizes the evidence and the evidence gaps for the diagnosis, investigation, management, and outcomes of pediatric hypertension.

B-Type Natriuretic Peptide Levels and Cardiac Dysfunction in Children on Peritoneal Dialysis

Background

Abnormalities in left ventricular (LV) structure and function are prevalent in patients on peritoneal dialysis (PD). The risk of cardiovascular mortality is also 10 – 20 times higher in PD patients than in age- and gender-matched healthy control subjects.

Methods

Echocardiography was performed annually or every 6 months for children on PD; the frequency was increased if the patient had hypertension or any heart problem. We retrospectively reviewed echocardiographic findings of these children (since February 2005) by chart review. The linear regression analysis of log(B-type natriuretic peptide, BNP) was performed to evaluate the association between serum BNP and cardiac parameters on echocardiography.

Results

We enrolled 52 patients and evaluated 169 echocardiographic findings in association with serum BNP levels. Systolic blood pressure (adjusted R2 = 0.321), diastolic blood pressure (adjusted R2 = 0.292), LV posterior wall thickness at diastole (0.058), LV posterior wall thickness at systole (0.038), LV internal diameter at diastole (0.177), LV internal diameter at systole (0.132), LV mass index (0.122), thickness of interventricular septum at diastole (0.035), the left atrial (LA) diameter (0.201), LA/aorta diameter ratio (0.113), lateral E/E’ (0.229), and lateral A'/E’ (0.149) showed positive correlation with log(BNP); conversely, LV fractional shortening (FS) (0.065), LV ejection fraction (0.082), right ventricular internal diameter at diastole (0.184), right ventricular fractional shortening (0.754), lateral S’ (0.179), and lateral E’ (0.161) showed negative correlation with log(BNP).

Conclusions

Routine measurement of serum BNP is recommended in children on PD to evaluate the risk of morphological and functional cardiac problems.

Pediatric Hypertension

The prevalence of elevated blood pressure and hypertension in children and adolescents has increased over the past decade. This trend is most likely related to increases in primary hypertension associated with increasing obesity rates in children. Lifestyle as well as genetics play a significant role in the development of primary hypertension. Hypertension in children and adolescents is under-recognized and undertreated. The 2017 Revised Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents aimed to create new normative blood pressure tables using data from healthy weight children, meaning between the 5th and 85th percentile per the Centers for Disease Control and Prevention. Another important objective was to simplify normative data to ease screening and detection of elevated blood pressures. The consequences of chronic hypertension are significant, with its major affect being in poor cardiovascular health outcomes both in childhood and early adulthood. Challenges to detection and adequate treatment should be overcome with continued education and awareness to prevent the long-term effects of uncontrolled hypertension that starts in childhood. [Pediatr Ann. 2018;47(12):e499-e503.].

[Blood pressure profile in adolescents at school in Lubumbashi, Democratic Republic of the Congo]

Introduction

L'objectif de cette étude était de donner le profil de la pression artérielle (PA) des adolescents âgés de 15 à 19 ans en milieu scolaire à Lubumbashi, République Démocratique du Congo.

Méthodes

il s'agit d'une étude transversale, portant sur les adolescents âgés de 15 à 19 ans au moyen d'un échantillonnage aléatoire des écoles secondaires de Lubumbashi durant les années scolaires 2013-2014, 2014-2015 et 2015-2016. Trois mesures de PA étaient effectuées le même jour.

Résultats

1766 adolescents âgés de 15-19 ans ont été inclus parmi eux 995 étaient de sexe féminin et 771 garçons. Les garçons avaient significativement une pression artérielle systolique élevée que les filles dans les tranches d'âges de 17, 18 et 19 ans. La pression artérielle diastolique n'était pas différente statistiquement dans toutes les tranches d'âges dans les deux sexes. Par contre, dans les deux sexes, la pression artérielle systolique été en corrélation significative avec le poids, la taille, l'indice de masse corporelle, le tour de taille et la fréquence cardiaque. Quant à la pression artérielle diastolique, des corrélations significatives étaient retrouvées avec le poids et l'indice de masse corporelle chez les filles alors que la fréquence cardiaque était en corrélation significative dans les deux sexes.

Discussion

Au cours de notre étude, il était question de déterminer les valeurs moyennes de PA et sa corrélation avec les paramètres anthropométriques, la FC et le poids de naissance chez les adolescents d'âge compris entre 15 et 19 ans. Notre étude a révélé des valeurs moyennes de PAS chez les garçons qui étaient plus élevées que les filles statistiquement significatives dans les tranches d'âges de 17, 18 et 19 ans alors que les valeurs moyennes de PAD n'avait pas de différence statistiquement significative dans toutes les tranches d'âges dans les deux sexes. Harrabi et al. [16], dans leur étude incluant 1569 sujets âgés de 13 à 19 ans, avaient trouvé que les garçons de 16, 17 et 18 ans avaient des PAS élevées sans différence statistiquement significatives mais les différences statistiquement significatives étaient remarquées chez les filles de 13 et 14 ans concernant la PAD. Dans son étude chez les enfants, Forrester et al. [17] avaient rapporté une corrélation positive entre la PAS et l'âge chez les garçons et négative chez les filles. Cette corrélation négative trouvée entre la PAS et l'âge chez les filles pourrait être expliquée par les modifications hormonales liées à la puberté qui commencent plus tôt chez les filles que chez les garçons. Se référant à la littérature, la PA augmente avec la croissance en âge plus chez les garçons suite à l'augmentation de la masse musculaire pendant la puberté [18-20].

Notre étude a montré que la PAS était en corrélation significative avec le poids, la taille, l'IMC, le tour de taille et la FC dans les deux sexes. Ce constat est similaire à celui faite par l'étude de Harrabi et al. [16] qui rapportait que la PAS était en corrélation positive avec la taille (garçons: r = 0,33; p < 0,0001; filles: r = 0,08; p = 0,02), le poids (garçons: r = 0,47, p < 0,0001; filles: r = 0,35; p < 0,0001) et l'âge (r = 0,12; p < 0,0001). Quant à la PAD dans notre étude, les corrélations significatives positives étaient retrouvées avec le poids (r = 0,093; p = 0,003) et l'IMC (r = 0,079; p = 0,012) seulement chez les filles, alors que la FC était en corrélation significative positive chez les garçons (r = 0,168; p < 0,0001) mais non chez les filles (r = 0,12, p < 0,0001) [16]. Dans une étude similaire chez les adolescents réalisée par Sinaiko et al. [21], une corrélation a été trouvée entre le poids et la PAS chez les garçons (r = 0,167, p < 0,0001) et les filles (r = 0,112, p < 0,0001). L'effet de la taille et du poids sur la PA a déjà été démontré dans plusieurs études transversales antérieures sur les enfants concluant en une forte corrélation positive [22,23]. L'insuffisance de déclaration des naissances à l'état civil dans plusieurs pays en développement, conséquente au recours aux poids de naissance déclarés auprès des parents ou tuteurs, serait un biais dans la réalisation des résultats statistiquement comparables.

Conclusion

Malgré les faiblesses potentielles de la présente étude dans sa conception transversale et les mesures de la PA le même jour, les données pourraient aider les responsables de la santé à adopter une stratégie nationale de prévention de l'hypertension artérielle dans notre population.

High blood pressure in the young: why should we care?

While primary hypertension (HTN) clearly occurs in children and adolescents, the approach of many providers to such patients can best be described as ambivalent: the condition may be recognised, but is not acted upon. Such ambivalence may stem from incomplete understanding of the effects of high blood pressure in the young, which in turn is related to the shortage of information on long-term outcomes of primary childhood HTN. However, other evidence on the short- and long-term effects of blood pressure elevation in childhood clearly shows that it is not a benign condition at all.

CONCLUSION

Childhood HTN warrants action to prevent adult cardiovascular disease.

Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents

These pediatric hypertension guidelines are an update to the 2004 "Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents." Significant changes in these guidelines include (1) the replacement of the term "prehypertension" with the term "elevated blood pressure," (2) new normative pediatric blood pressure (BP) tables based on normal-weight children, (3) a simplified screening table for identifying BPs needing further evaluation, (4) a simplified BP classification in adolescents ≥13 years of age that aligns with the forthcoming American Heart Association and American College of Cardiology adult BP guidelines, (5) a more limited recommendation to perform screening BP measurements only at preventive care visits, (6) streamlined recommendations on the initial evaluation and management of abnormal BPs, (7) an expanded role for ambulatory BP monitoring in the diagnosis and management of pediatric hypertension, and (8) revised recommendations on when to perform echocardiography in the evaluation of newly diagnosed hypertensive pediatric patients (generally only before medication initiation), along with a revised definition of left ventricular hypertrophy. These guidelines include 30 Key Action Statements and 27 additional recommendations derived from a comprehensive review of almost 15 000 published articles between January 2004 and July 2016. Each Key Action Statement includes level of evidence, benefit-harm relationship, and strength of recommendation. This clinical practice guideline, endorsed by the American Heart Association, is intended to foster a patient- and family-centered approach to care, reduce unnecessary and costly medical interventions, improve patient diagnoses and outcomes, support implementation, and provide direction for future research.

Fibroblast growth factor-23 is independently associated with cardiac mass in African-American adolescent males

Left ventricular hypertrophy has been documented in hypertensive adolescents and among some with prehypertension. Obesity also appears to be associated with cardiac mass, independent of blood pressure (BP). Fibroblast growth factor 23 (FGF23) is a novel biomarker positively associated with left ventricular hypertrophy in adults with and without kidney disease. The aim of this study was to determine if there was a significant and independent association of FGF23 with cardiac mass in a Black American adolescent cohort including both normotensive and prehypertensive participants with and without obesity. Measurements of BP, body mass index (BMI), plasma c-terminal FGF23, and echocardiographic measures of left ventricular mass index (LVMI) were obtained in 236 adolescents, aged 13-18 years, stratified by BMI as normal, overweight, or obese. LVMI differed significantly between normal, overweight, and obese groups (30.42 ± 6.75 vs. 33.49 ± 8.65 vs. 37.26 ± 6.99 gm/m^2.7; P < .01). FGF23 was significantly higher in both overweight (53.03 RU/mL) and obese (54.40 RU/mL) compared to the normal weight (32.83 RU/mL) group (both P < .01). In multiple linear regression analysis, variables significantly related to LVMI in males were BMI (P < .0001) and FGF23 (P = .005), but not BP, high-sensitivity C-reactive protein, or insulin. The only significant variable associated with LVMI in females was BMI (P < .0001). In males, the contribution of FGF23 to predicting LVMI was independent of and in addition to obesity. These results suggest that FGF23 is an integral part of a complex pathway, associated with higher cardiac mass in African-Americans males with excess adiposity.

ECG is an inefficient screening-tool for left ventricular hypertrophy in normotensive African children population

Background

Left ventricular hypertrophy (LVH) is a marker of pediatric hypertension and predicts development of cardiovascular events. Electrocardiography (ECG) screening is used in pediatrics to detect LVH thanks to major accessibility, reproducibility and easy to use compared to transthoracic echocardiography (TTE), that remains the standard technique. Several diseases were previously investigated, but no data exists regarding our study population. The aim of our study was to evaluate the relationship between electrocardiographic and echocardiographic criteria of LVH in normotensive African children.

Methods

We studied 313 children (mean age 7,8 ± 3 yo), in north-Madagascar. They underwent ECG and TTE. Sokolow-Lyon index was calculated to identify ECG-LVH (>35 mm). Left ventricle mass (LVM) with TTE was calculated and indexed by height^2.7 (LVMI^2.7) and weight (LVMI^w). We report the prevalence of TTE-LVH using three methods: (1) calculating percentiles age- and sex- specific with values >95th percentile identifying LVH; (2) LVMI^2.7 >51 g/m^2.7; (3) LVMI^w >3.4 g/weight.

Results

40 (13%) children showed LVMI values >95th percentile, 24 children (8%) an LVMI^2.7 >51 g/m^2.7 while 19 children (6%) an LVMI^w >3.4 g/kg. LVH-ECG by Sokolow-Lyon index was present in five, three and three children respectively, with poor values of sensitivity (ranging from 13 to 16%), positive predictive value (from 11 to 18%) and high values of specificity (up to 92%). The effects of anthropometrics parameters on Sokolow-Lyon were analyzed and showed poor correlation.

Conclusion

ECG is a poor screening test for detecting LVH in children. In clinical practice, TTE remains the only tool to be used to exclude LVH.

The Prevalence of Left Ventricular Hypertrophy in Obese Children Varies Depending on the Method Utilized to Determine Left Ventricular Mass

Obesity and left ventricular hypertrophy (LVH) have been identified as independent risk factors for cardiovascular events. The definition of LVH depends on the geometric algorithm used to calculate LV mass (LVM) by echocardiography and the method used to normalize LVM for body size. This study evaluates the effect of these methods on the prevalence of LVH in obese children. LVM for 109 obese and 109 age-matched non-obese children was calculated using M-mode or two-dimensional echocardiography (2DE). LVM was then normalized to height 2.7 as indexed LVM (LVMI), to body surface area (BSA), height, and lean body mass (LBM) as LVM Z-scores. LVH was defined as LVMI >95th ‰ using age-specific normal reference values or LVM Z-scores ≥2. The prevalence of LVH by LVMI and LVM Z-scores was compared. There was a correlation between LVM determined by M-mode and by 2DE (R (2) = 0.91), although M-mode LVM was greater than 2DE LVM. However, the difference between these values was greater in obese children than in non-obese children. Based on the method of normalization, the prevalence of LVH among obese children was 64 % using LVMI, 15 % using LVM Z-scores for height, 8 % using LVM Z-scores for BSA and 1 % using LVM Z-scores for LBM. Height-based normalization correlates with obesity and hypertension. The methods used to measure and normalize LVM have a profound influence on the diagnosis of LVH in obese children. Further study is needed to determine which method identifies children at risk for cardiovascular morbidity and mortality.

Elevated dietary sodium intake exacerbates myocardial hypertrophy associated with cardiac-specific overproduction of angiotensin II

Introduction/hypothesis

Cardiac hypertrophy is an independent risk factor predictive of cardiovascular disease and is significantly associated with morbidity and mortality. The mechanism by which angiotensin II (Ang II) and dietary sodium exert additive effects on the development of cardiac hypertrophy is unclear. The goal of this study was to evaluate the hypothesis that, where there is a genetic predisposition to Ang II-dependent hypertrophy, there is also an increased susceptibility to sodium-induced hypertrophy mediated by AT1-receptor expression.

Methods

Diets of low sodium (LS, 0.3% w:w) and high sodium (HS, 4.0% w:w) content were fed to adult (age 25 weeks) control wild-type mice (WT) and to weeks) control wild-type mice (WT) and to transgenic mice exhibiting cardiac specific overexpression of angiotensinogen (TG). At the conclusion of a 40-day dietary treatment period, cardiac tissue weights were compared and the relative expression levels of Ang II receptor subtypes (AT1A and AT2) were evaluated using RT-PCR.

Results

WT and TG mice fed HS and LS diets maintained comparable weight gains during the treatment period. The normalised heart weights of TG mice were elevated compared to WT, and the extent of the increase was greater for mice maintained on the HS diet treatments (WT 12% vs. TG 41% increase in cardiac weight index). While a similar pattern of growth was observed for ventricular tissues, the atrial weight parameters demonstrated an additional significant effect of dietary sodium intake on tissue weight, independent of animal genetic type. No differences in the relative (GAPDH normalised) expression levels of AT1A- and AT2-receptor mRNA were observed between diet or animal genetic groups.

Conclusion

This study demonstrates that, where there is a pre-existing genetic condition of Ang II-dependent cardiac hypertrophy, the pro-growth effect of elevated dietary sodium intake is selectively augmented. In TG and WT mice, this effect was evident with a relatively short dietary treatment intervention (40 days). Evaluation of the levels of Ang II receptor mRNA further demonstrated that this differential growth response was not associated with an altered relative expression of either AT1A- or AT2-receptor subtypes. The cellular mechanistic bases for this specific Ang II-dietary sodium interaction remain to be elucidated.

Burden of Hypertension and Abnormal Glomerular Permeability in Hypertensive School Children

Background

Childhood hypertension has been associated with target-organ damage in young adults. It is often asymptomatic in both children and adolescents; when persistent, and long-standing, it could be a significant risk factor for kidney damage and increased glomerular permeability.

Objectives

Burden of hypertension and its impact on glomerular permeability were prospectively determined in randomly recruited primary school children.

Patients and Methods

Blood pressure (BP) measurement was performed by the auscultation method, and abnormal glomerular permeability was assessed by dipstick testing of urine for persistent proteinuria and/or hematuria for ≥ three months in hypertensive children.

Results

Of 1,335 pupils aged 10.0 ± 2.4 (6.0 - 14.0) years, 33 (2.5%) were hypertensive. Overall mean systolic/diastolic BP was 125.6 ± 6.5/81.7 ± 3.3 (range: 114.0 - 140.0/80.0 - 90.0) mmHg. Nine (27.3%) had combined systolic and diastolic hypertension, 126.7 ± 5.7/80.0 - 80.0 ± 0.0 (120.0 - 130.0/80.0 - 80.0) mmHg. Isolated systolic hypertension, 125.4 ± 6.7 (114.0 - 140.0) mmHg, was present in 14 (42.4%), whereas 10 (30.3%) had isolated diastolic hypertension, 82.0 ± 3.5 (80.0 - 90.0) mmHg. Mean systolic and diastolic BP were 131.0 ± 3.3 (130.0 - 140.0) mmHg and 86.5 ± 4.43 (80.0 - 90.0) mmHg, respectively. According to the dipstick test, none of the hypertensive pupils showed urinalysis evidence of proteinuria and/or hematuria after three months of testing.

Conclusions

Although the burden of hypertension was 2.5%, the dipstick method did not detect any hypertension-related abnormal glomerular permeability in the school children.

Left atrial dimension is related to blood pressure variability in newly diagnosed untreated hypertensive patients

Variability in daily blood pressure (BPV) recorded 24-h ambulatory blood pressure monitoring (ABPM) is known to be related to left ventricular hypertrophy and an increased incidence of cardiovascular events in hypertensive patients. The aim of this study was to evaluate whether left atrium dimension, which increases early in hypertensive subjects, was related to BPV in a group of 167 drug-naive patients (100M/67F, age: 46±11yr). The patients were chosen among those consecutively sent by their general practitioners to confirm the existence of arterial hypertension and afterwards diagnosed as hypertensive (mean 24-h ABPM ⩾130/80 mm Hg). In each patient, the left atrial posteroanterior diameter index for height (LADi) and the left ventricular mass standardized for body surface area (LVMi) were measured using standardized echocardiographic methods. BPV was calculated as the weighted mean of daytime and nighttime systolic and diastolic blood pressure s.d.'s (ws.d.), according to the formula ws.d.=[(daytime s.d. × 10)+nighttime s.d. × 6)]/16. An increase in left atrial dimension (LADi>24 mm m(-1)) was present in 36 patients (21.6% of the total population). In a univariate regression, LVMi was significantly related to systolic BPV (r=0.24; P=0.02) only in men, whereas LADi was significantly related to both systolic and diastolic BPV in both genders. After adjusting for sex, age, BMI, heart rate, diastolic function and estimated glomerular filtration rate, both systolic and diastolic BPV remained significantly related to LADi (P=0.02 for both) but not to LVMi. In conclusion, this study suggests that BVP, as measured as BPws.d., is significantly and independently associated with increased LADi in newly diagnosed, treatment-naive hypertensive patients.

Left Ventricular Mass Indexing in Infants, Children, and Adolescents: A Simplified Approach for the Identification of Left Ventricular Hypertrophy in Clinical Practice

OBJECTIVE

To determine a simplified method to identify presence of left ventricular hypertrophy (LVH) in pediatric populations because the relationship between heart growth and body growth in children has made indexing difficult for younger ages.

STUDY DESIGN

Healthy children (n = 400; 52% boys, 0-18 years of age) from 2 different European hospitals were studied to derive a simplified formula. Left ventricular mass (LVM) was calculated according to the Devereux formula. The derived approach to index LVM was tested on a validation cohort of 130 healthy children from a different hospital center.

RESULTS

There was a strong nonlinear correlation between height and LVM. LVM was best related to height to a power of 2.16 with a correction factor of 0.09. Analysis of residuals for LVM/[(height(2.16)) + 0.09] showed an homoscedastic distribution in both sexes throughout the entire height range. A partition value of 45 g/m(2.16) was defined as the upper normal limit for LVM index. As opposed to formula suggested by current guidelines (ie, LVM/height(2.7)) when applying the proposed approach in the validation cohort of 130 healthy participants, no false positives for LVH were found (0% vs 8%; P < .01).

CONCLUSIONS

Our data support the possibility to have a single partition (ie, 45 g/m(2.16)) value across the whole pediatric age range to identify LVH, without the time-consuming need of computing specific percentiles for height and sex.

Hypertensive cardiomyopathy: A clinical approach and literature review

Hypertensive cardiomyopathy (HTN-CM) is a structural cardiac disorder generally accompanied by concentric left ventricular hypertrophy (LVH) associated with diastolic or systolic dysfunction in patients with persistent systemic hypertension. It occurs in the absence of other cardiac diseases capable of causing myocardial hypertrophy or cardiac dysfunction. Persistent systemic hypertension leads to structural and functional myocardial abnormalities resulting in myocardial ischemia, fibrosis, and hypertrophy. HTN-CM is predominantly a disease of impaired relaxation rather than impaired contractility, so patients are usually asymptomatic during resting conditions. However, their stiff left ventricles become incapable of handling increased blood volume and cannot produce appropriate cardiac output with the slight change of circulating volume that may occur during exercise. Importantly, the accompanying LVH is itself a risk factor for mortality and morbidity. Therefore, early detection of LVH development in patients with hypertension (referred to as HTN-CM) is critical for optimal treatment. In addition to pathological findings, echocardiography and cardiac magnetic resonance imaging are ideal tools for the diagnosis of HTN-CM. Timely diagnosis of this condition and utilization of appropriate treatment are required to improve morbidity and mortality in hypertensive patients. This review article presents an overview of the multidimensional impact of myocardial disorder in patients with hypertension. Relevant literature is highlighted and the effects of hypertension on cardiac hypertrophy and heart failure development are discussed, including possible therapeutic options.

Relationship of Systolic Blood Pressure and Body Mass Index With Left Ventricular Mass and Mass Index in Adolescents

Prevalence of hypertension (HT) is growing among children and adolescents. Its diagnosis is commonly ignored as it does not produce any end-organ damage in adolescents. We evaluated whether the blood pressure (BP) and confounding factors were related to myocardial mass increase; an earlier representative of HT; among adolescents. We have demonstrated that heart rate, body mass index (BMI), left ventricular mass (LVM), interventricular septum, and LV mass indexed to body surface area (BSA) and height significantly increased as the category of BP increased. We have also showed that the systolic BP (SBP), diastolic BP (DBP), and BMI were significantly correlated with the LVM and LVM indexed to BSA and height. Linear regression analysis revealed a significant relationship between SBP, BMI, and LVM, LVM indexed to BSA and height. Hypertension may cause myocardial hypertrophy even at a young age. Height is an alternative and practical way of determining the left ventricular mass index (LVMI) in adolescents. The BMI is significantly related to LVM and LVMI as well as SBP and DBP are. The results support that overweight and obesity should be controlled strictly in the management of HT in a young population.

Cardiac target organ damage in hypertension: insights from epidemiology

Hypertension is an important risk factor implicated in the development of multiple common cardiac conditions, including coronary atherosclerosis, heart failure, and atrial fibrillation. Epidemiologic studies have provided insights into the shared pathogenesis of hypertension and subclinical as well as clinically evident cardiac diseases. The mechanistic common ground between chronic blood pressure elevation and cardiac disease likely begins early in life. Understanding these connections will aid ongoing efforts to identify individuals at risk, develop targeted therapeutics, and improve overall outcomes for individuals with elevated blood pressure in the population at large.

Essential hypertension vs. secondary hypertension among children

BACKGROUND

The aim was to determine the proportions and correlates of essential hypertension among children in a tertiary pediatric hypertension clinic.

METHODS

We evaluated 423 consecutive children and collected demographic and clinical history by retrospective chart review.

RESULTS

We identified 275 (65%) hypertensive children (blood pressure >95th percentile per the "Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents") from 423 children referred to the clinic for history of elevated blood pressure. The remainder of the patients had normotension (11%), white coat hypertension (11%), prehypertension (10%), and pending diagnosis (3%). Among the 275 hypertensive children, 43% (n = 119; boys = 56%; median age = 12 years; range = 3-17 years) had essential hypertension and 57% (n = 156; boys = 66%; median age = 9 years; range = 0.08-19 years) had secondary hypertension. When compared with those with secondary hypertension, those with essential hypertension had a significantly older age at diagnosis (P = 0.0002), stronger family history of hypertension (94% vs. 68%; P < 0.0001), and lower prevalence of preterm birth (20% vs. 46%; P < 0.001). There was a bimodal distribution of age of diagnosis in those with secondary hypertension.

CONCLUSIONS

The phenotype of essential hypertension can present as early as 3 years of age and is the predominant form of hypertension in children after age of 6 years. Among children with hypertension, those with essential hypertension present at an older age, have a stronger family history of hypertension, and have lower prevalence of preterm birth.

Evidence of a hyperkinetic state in children with elevated blood pressure

BACKGROUND

Left ventricular hypertrophy (LVH) and elevated left ventricular mass index (LVMI) are important predictors of cardiovascular morbidity and mortality in adults. Children with hypertension and pre-hypertension demonstrate LVH and greater LVMI compared to normotensive children. The impact of blood pressure (BP) on early changes in left ventricular properties provides an opportunity to understand and identify cardiovascular risk early in childhood.

AIM

The aim of this study was to assess left ventricular structural and functional properties in a sample of children across a wide range of BP values.

SUBJECTS AND METHODS

Children aged 11-14-years were divided into BP groups: hypertensives (HTN; ≥95th percentile; n = 21) and normotensives (NTN; <90th percentile; n = 85) based on BP measures taken at two time points. Resting supine heart rate (HR), cardiac output (CO) and total peripheral resistance (TPR) were collected along with left ventricular structural and functional properties using ultrasound sonography.

RESULTS

LVMI and TPR were not different between groups. CO, HR and left ventricular end-diastolic and end-systolic volumes were elevated in the HTN group. Furthermore, HR and body mass index were found to be independent predictors of BP group status in children.

CONCLUSION

These findings show that children with elevated BP are characterized by high HR and CO and normal TPR. Also, the results identify HR as a predictor of BP group status in early childhood.

Detection of early diastolic alterations by tissue Doppler imaging in untreated childhood-onset essential hypertension

The aim of the study was to determine the presence of preclinical diastolic dysfunction in hypertensive children relative to normotensive children by Tissue Doppler Imaging (TDI). We prospectively enrolled children with untreated essential hypertension in absence of any other disease and a matched healthy control group with normal blood pressure (BP); both groups confirmed by clinic BP and a 24-hour ambulatory BP monitoring. Echocardiographic diastolic parameters were determined using spectral transmitral inflow Doppler, flow propagation velocity, TDI, and systolic parameters were determined via midwall shortening fraction and ejection fraction. A total of 80 multiethnic children were prospectively enrolled for the study: 46 hypertensive (median age, 13 years; 72% males) and 34 control (median age, 14 years; 65% males). The only echocardiography parameters that had a statistically significant change compared with the control children, were regional mitral Ea, Aa, and the E/Ea ratio by TDI. In comparison with controls, hypertensive children had lower Ea and Aa velocities of anterior and posterior walls and higher lateral wall E/Ea ratio. The decrease in posterior wall Ea and Aa remained significant after adjustment for gender, age, body mass index, ethnicity, and left ventricular hypertrophy on multivariate analysis. The lateral and septal wall E/Ea ratios correlated significantly with fasting serum insulin levels on similar multivariate analysis. Decreased regional TDI velocities were seen with preserved left ventricular systolic function even when other measures of diastolic dysfunction remained unchanged in untreated hypertensive children. Hypertension and serum insulin levels had strong associations with preclinical diastolic alterations in children.

Sodium intake and blood pressure in children

Elevation of blood pressure (BP) and the risk for progression to hypertension (HTN) is of increasing concern in children and adolescents. Indeed, it is increasingly recognized that target organ injury may begin with even low levels of BP elevation. Sodium intake has long been recognized as a modifiable risk factor for HTN. While it seems clear that sodium impacts BP in children, its effects may be enhanced by other factors including obesity and increasing age. Evidence from animal and human studies indicates that sodium may have adverse consequences on the cardiovascular system independent of HTN. Thus, moderation of sodium intake over a lifetime may reduce risk for cardiovascular morbidity in adulthood. An appetite for salt is acquired, and intake beyond our need is almost universal. Considering that eating habits in childhood have been shown to track into adulthood, modest sodium intake should be advocated as part of a healthy lifestyle.

Factors influencing left ventricular hypertrophy in children and adolescents with or without family history of premature myocardial infarction

BACKGROUND

Cardiovascular diseases are the highest ranking cause of mortality. The prevalence of cardiovascular diseases is increasing among people in developed and developing countries. Since left ventricular hypertrophy is one of the risk factors leading to extremely dangerous heart diseases and even sudden death at early ages, investigating its contributing factors can be beneficial. The purpose of this study was to determine factors contributing to left ventricular hypertrophy in students aged 7-18 years in Isfahan. Statistical population of this case-control study was the 7-18 year old students in Isfahan, who were studied in two groups of children with premature myocardial infarction in their parents and the control group.

MATERIALS AND METHODS

After determining the sample size of 138 people, a two-part questionnaire was designed and demographic characteristics and anthropometric measures were recorded in students' profiles. The obtained information was analyzed using SPSS15 software and logistic regression model and the results were reported at P < 0.05.

RESULT

The results showed that among the studied variables, gender, age, body mass index, and blood pressure were associated with the left ventricular hypertrophy.

CONCLUSION

Considering the results and previous studies in this field, it was observed that left ventricular hypertrophy exists at early ages, which is very dangerous and can lead to heart diseases at early ages. Factors such as being overweight, having high blood pressure, and being male cause left ventricular hypertrophy and lead to undiagnosable heart diseases.

High risk blood pressure and obesity increase the risk for left ventricular hypertrophy in African-American adolescents

OBJECTIVE

To examine the relative effects of high blood pressure (HBP) and obesity on left ventricular mass (LVM) among African-American adolescents; and if metabolic or inflammatory factors contribute to LVM.

STUDY DESIGN

Using a 2 × 2 design, African-American adolescents were stratified by body mass index percentile (body mass index <95th percentile = non-obese; ≥ 95th percentile = obese) and average blood pressure (BP) (normal BP <120/80 mm Hg; HBP ≥ 120/80). Glucose, insulin, insulin resistance, lipids, and inflammatory cytokines were measured. From echocardiography measures of LVM, calculated LVM index (LVMI) ≥ 95th percentile defined left ventricular hypertrophy (LVH).

RESULTS

Data included 301 adolescents (48% female), mean age 16.2 years, 51% obese, and 29% HBP. LVMI was highest among adolescents with both obesity and HBP. The multiplicative interaction of obesity and HBP on LVH was not significant (OR = 2.35, P = .20) but the independent additive associations of obesity and HBP with log-odds of LVH were significant; obesity OR = 3.26, P < .001; HBP OR = 2.92, P < .001. Metabolic and inflammatory risk factors were associated with obesity, but had no independent association with LVMI. Compared with those with average systolic BP (SBP) <75th percentile, adolescents with SBP from the 75th percentile to 90th percentile had higher LVMI (33.2 vs 38.7 g/m(2.7), P < .001) and greater LVH (18% vs 43%, P < .001), independent of obesity.

CONCLUSIONS

Prevalence of LVH is highest among African-American adolescents with average BP ≥ 120/80 mm Hg and obesity. There also is an independent association of LVMI with BP, beginning at the 75th SBP percentile.

Effects of kimchi supplementation on blood pressure and cardiac hypertrophy with varying sodium content in spontaneously hypertensive rats

We tested the effects of dietary intake of freeze-dried Korean traditional fermented cabbage (generally known as kimchi) with varying amounts of sodium on blood pressure and cardiac hypertrophy in spontaneously hypertensive rats (SHRs). Wistar-Kyoto rats (WKY), as a control group, received a regular AIN-76 diet, and the SHRs were divided into four groups. The SHR group was fed a regular diet without kimchi supplementation, the SHR-L group was fed the regular diet supplemented with low sodium kimchi containing 1.4% salt by wet weight, which was provided in a freeze-dried form, the SHR-M group was supplemented with medium levels of sodium kimchi containing 2.4% salt, and the SHR-H group was supplemented with high sodium kimchi containing 3.0% salt. Blood pressure was measured over 6 weeks, and cardiac hypertrophy was examined by measuring heart and left ventricle weights and cardiac histology. SHRs showed higher blood pressure compared to that in WKY rats, which was further elevated by consuming high sodium containing kimchi but was not influenced by supplementing with low sodium kimchi. None of the SHR groups showed significant differences in cardiac and left ventricular mass or cardiomyocyte size. Levels of serum biochemical parameters, including blood urea nitrogen, creatinine, glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase, sodium, and potassium were not different among the groups. Elevations in serum levels of aldosterone in SHR rats decreased in the low sodium kimchi group. These results suggest that consuming low sodium kimchi may not adversely affect blood pressure and cardiac function even under a hypertensive condition.

Salt and hypertension: is salt dietary reduction worth the effort?

In numerous epidemiologic, clinical, and experimental studies, dietary sodium intake has been linked to blood pressure, and a reduction in dietary salt intake has been documented to lower blood pressure. In young subjects, salt intake has a programming effect in that blood pressure remains elevated even after a high salt intake has been reduced. Elderly subjects, African Americans, and obese patients are more sensitive to the blood pressure-lowering effects of a decreased salt intake. Depending on the baseline blood pressure and degree of salt intake reduction, systolic blood pressure can be lowered by 4 to 8 mm Hg. A greater decrease in blood pressure is achieved when a reduced salt intake is combined with other lifestyle interventions, such as adherence to Dietary Approaches to Stop Hypertension. A high salt intake has been shown to increase not only blood pressure but also the risk of stroke, left ventricular hypertrophy, and proteinuria. Adverse effects associated with salt intake reduction, unless excessive, seem to be minimal. However, data linking a decreased salt intake to a decrease in morbidity and mortality in hypertensive patients are not unanimous. Dietary salt intake reduction can delay or prevent the incidence of antihypertensive therapy, can facilitate blood pressure reduction in hypertensive patients receiving medical therapy, and may represent a simple cost-saving mediator to reduce cardiovascular morbidity and mortality.

The Association of Hypertension with Obesity and Metabolic Abnormalities among Chinese Children

A total of 8898 Chinese children (4580 boys and 4318 girls) aged 7–13 years in 6 cities of east China were recruited. Data on height, weight, waist circumference, blood pressure, serum lipid profiles, glucose, and insulin were collected. The overall prevalence of hypertension was 11.1%. Overweight and obese children had a higher risk of developing hypertension than their counterparts (29.1%, 17.4%, and 7.8%, resp.) (P = 0.0001). The means levels of triglycerides, glucose, insulin, and HOMA-IR (1.0 mmol/L, 4.5 mmol/L, 8.4 mU/mL and 1.7, resp.) among hypertensive children were all significantly higher than their normotensive counterparts (0.8 mmol/L, 4.5 mmol/L, 5.9 mU/mL, and 1.2, resp.) (P = 0.0001). Compared with the healthy children, the risk (odds ratio, OR) of having hypertension among children with high triglycerides, hyperglycemia, and metabolic syndrome was 1.4 (95% confidence interval (CI): 1.0–2.0, P = 0.0334), 1.5 (95% CI: 0.9–2.5, P = 0.0890), and 2.8 (95%CI: 1.5–5.4, P = 0.0014), respectively, after controlling for age, gender, BMI, income level, parents' education level and puberty. In conclusion, overweight and obese children have higher risk of having hypertension and children with dyslipidemia, hyperglycemia, and metabolic syndrome and higher HOMA-IR have higher risk of developing hypertension.

Association of blood pressure in late adolescence with subsequent mortality: cohort study of Swedish male conscripts

OBJECTIVE

To investigate the nature and magnitude of relations of systolic and diastolic blood pressures in late adolescence to mortality.

DESIGN

Nationwide cohort study.

SETTING

General community in Sweden.

PARTICIPANTS

Swedish men (n = 1,207,141) who had military conscription examinations between 1969 and 1995 at a mean age of 18.4 years, followed up for a median of 24 (range 0-37) years.

MAIN OUTCOME MEASURES

Total mortality, cardiovascular mortality, and non-cardiovascular mortality.

RESULTS

During follow-up, 28,934 (2.4%) men died. The relation of systolic blood pressure to total mortality was U shaped, with the lowest risk at a systolic blood pressure of about 130 mm Hg. This pattern was driven by the relation to non-cardiovascular mortality, whereas the relation to cardiovascular mortality was monotonically increasing (higher risk with higher blood pressure). The relation of diastolic blood pressure to mortality risk was monotonically increasing and stronger than that of systolic blood pressure, in terms of both relative risk and population attributable fraction (deaths that could be avoided if blood pressure was in the optimal range). Relations to cardiovascular and non-cardiovascular mortality were similar, with an apparent risk threshold at a diastolic blood pressure of about 90 mm Hg, below which diastolic blood pressure and mortality were unrelated, and above which risk increased steeply with higher diastolic blood pressures.

CONCLUSIONS

In adolescent men, the relation of diastolic blood pressure to mortality was more consistent than that of systolic blood pressure. Considering current efforts for earlier detection and prevention of risk, these observations emphasise the risk associated with high diastolic blood pressure in young adulthood.

Community based lifestyle intervention for blood pressure reduction in children and young adults in developing country: cluster randomised controlled trial

OBJECTIVE

To assess the effectiveness of a community based lifestyle intervention on blood pressure in children and young adults in a developing country setting.

DESIGN

Cluster randomised controlled trial.

SETTING

12 randomly selected geographical census based clusters in Karachi, Pakistan.

PARTICIPANTS

4023 people aged 5-39 years.

INTERVENTION

Three monthly family based home health education delivered by lay health workers.

MAIN OUTCOME MEASURE

Change in blood pressure from randomisation to end of follow-up at 2 years.

RESULTS

Analysed using the intention to treat principle, the change in systolic blood pressure (adjusted for age, sex, and baseline blood pressure) was significant; it increased by 1.5 (95% confidence interval 1.1 to 1.9) mm Hg in the control group and by 0.1 (-0.3 to 0.5) mm Hg in the home health education group (P for difference between groups=0.02). Findings for diastolic blood pressure were similar; the change was 1.5 mm Hg greater in the control group than in the intervention group (P=0.002).

CONCLUSIONS

Simple, family based home health education delivered by trained lay health workers significantly ameliorated the usual increase in blood pressure with age in children and young adults in the general population of Pakistan, a low income developing country. This strategy is potentially feasible for up-scaling within the existing healthcare systems of Indo-Asia.

TRIAL REGISTRATION

Clinical trials NCT00327574.

Effects of body size and body fatness on left ventricular mass in children and adolescents: Project HeartBeat!

BACKGROUND

Left ventricular mass (LVM) is a strong predictor of cardiovascular disease in adults. Available study findings on effects of body fatness on LVM in children are inconsistent. Understanding the impact of body fat on LVM in children may help prevent excessive LVM through measures to reduce overweight and obesity.

METHODS

Healthy children (n=678) aged 8, 11, and 14 years at baseline were examined at 4-month intervals for up to 4 years (1991-1995); 4608 valid measurements of LVM were obtained with M-mode echocardiography. A multilevel linear model was used for analysis. The impact of body size was examined by adding separately nine body-size indicators to a basic LVM-gender-age model. The impact of body fatness was tested by introducing four body-fatness indicators into the nine models, yielding 36 models.

RESULTS

All body-size indicators showed strong, positive effects on LVM. In models containing weight or body surface area (measuring both fat-free and fat contributions to body size), additional effects of body fatness were negative; in models containing fat-free mass (FFM) or height (both measuring body size independent of body fat), increased body fatness was related to a significant increase in LVM. For example, in models with FFM as a body-size indicator, a 1-SD increase in percent body fat or fat mass was related to a 5.4- or 7.2-g increase in LVM, respectively.

CONCLUSIONS

Effects of body size on LVM attributable to fat-free body mass can be distinguished from those attributable to fat body mass; both are independent, positive predictors, but the former is the stronger determinant. When a body-size indicator not independent of body fat is used as a predictor, effects of fat-free body mass and fat body mass are forced to relate to the same indicator; because their magnitudes are estimated to be equal, the effect of fat body mass is overestimated. Thus, when an additional body-fatness indicator is included in the prediction of LVM, the additional estimated effect related to the indicator appears to be negative.