Ability of blood pressure to predict left ventricular hypertrophy in children with primary hypertension

Sex, Obesity, and Blood Pressure Among African American Adolescents: The Jackson Heart KIDS Pilot Study

BACKGROUND

This study examined the degree to which sex, weight status, and the presence of hypertension and obesity in parents/grandparents were associated with systolic (SBP) and diastolic (DBP) blood pressure (BP) among African American youth in a pilot offspring study examining obesity-related cardiovascular disease (CVD) risks among adolescents.

RESULTS

Fully adjusted linear regression models of the total sample produced results indicating that obesity was associated with BP (SBP: β = 7.08, P < 0.01; DBP: β = 8.14, P < 0.001). Sex-stratified analyses indicated that overweight and obesity were associated with SBP (overweight: β = 6.77, P < 0.01; obese: β = 11.65, P < 0.001) and obesity was correlated with DBP (β = 9.86, P < 0.001) among males. For females, overweight was correlated with SBP (β = 4.11, P < 0.05) while obesity was associated with DBP (β = 6.98, P < 0.01). Attempting to lose weight was inversely related to SBP (β = -4.01, P < 0.05) in the full sample and among males (β = -11.94, P < 0.001). Familial presence of hypertension and/or obesity was significantly associated with SBP among adolescent females but not males.

CONCLUSIONS

The relationship between weight status, familial hypertension and obesity status, and BP among adolescents vary by sex. This study underscores the need for additional research investigating the relationship between individual sex, weight status, BP and familial BP, and obesity status on risk among African American adolescents.

Pediatric Hypertension: Provider Perspectives

Pediatric hypertension is a risk for adult cardiovascular disease, making early detection important. The prevalence of pediatric essential hypertension is rising due to the increased prevalence of obesity. Though guidelines for screening, diagnosis, evaluation, and management are available, there are barriers to accurate diagnosis of pediatric hypertension, including lack of knowledge and complexity of blood pressure standards. We aimed to gain insights into reasons for low rates of diagnosis and treatment from primary care providers. As part of a multisite randomized controlled trial, we interviewed 8 providers in a community health center network. We used a grounded theoretical approach to analyze transcripts. Providers reflected on numerous barriers to diagnosis, management, and follow-up; recommendations for educational content; and how community health center systems can be improved. Findings informed development of a multifaceted intervention. Despite lack of training on essential hypertension, providers were comfortable recommending lifestyle changes to promote healthier weight and reduced blood pressure.

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.

The association between obesity, hypertension and left ventricular mass in adolescents

BACKGROUND

Obesity and hypertension (HT) are well known cardiac risk factors. Our goal was to show that even if arterial blood pressure (BP) measurements of obese adolescents are normal during clinical examination, ambulatory blood pressure monitoring (ABPM) can be high, may include cardiac involvement and can also detect left ventricular mass indices (LVMI) value for obese adolescents to diagnose left ventricular hypertrophy (LVH).

METHODS

This study included 130 children (57 obese hypertensive, 36 obese normotensive, 14 normal weight hypertensive and 23 normal weight normotensive). Adolescents whose BP was measured during clinical examination, after 24-h BP was detected using ABPM, were examined with echocardiography for calculation of LVMI to determine cardiac risk factors for LVH.

RESULTS

There was a significant difference between the LVMI of obese-normotensive and obese-hypertensive adolescents, which showed the effect of obesity on LVMI independent of HT. Twenty (35.7%) of 56 obese adolescents with HT detected with ABPM had normal BP measurements during clinical examination. Dipper and nondipper features of obese adolescents were significantly higher in ABPM than those with normal body mass index. When the cutoff LVMI value for LVH was set at ≥38 g/m2.7, 38.9% of obese-normotensive and 50.9% of obese-hypertensive subjects had LVH; however, when the cutoff value was set at ≥51 g/m2.7, the rates were 2.8% and 19.3%, respectively.

CONCLUSIONS

Obesity is a risk factor for LVH independent of HT. To identify masked HT, 24-h ABPM and cardiac examination should be routinely performed in obese adolescents. Using a limit of LVMI ≥38 g/m2.7 in evaluating LVH secondary to HT in obese individuals may lead to an overestimated diagnosis rate of LVH.

Obesity-Related Hypertension in Children

Obesity and hypertension have both been on the rise in children. Each is associated with increased cardiovascular disease risk and both track into adulthood, increasing the prevalence of heart disease and related morbidity and mortality. All children should be screened for hypertension, but children with comorbid obesity may not only particularly benefit from the screening but may also prove the most challenging to screen. Increased arm circumference and conical arm shape are particularly problematic when attempting to obtain an accurate blood pressure (BP) measurement. This review focuses on the unique aspects of hypertension evaluation and management in the child with comorbid obesity. Specific traditional and non-traditional risk factors that may contribute to elevated BP in children with obesity are highlighted. Current proposed pathophysiologic mechanisms by which obesity may contribute to elevated BP and hypertension is reviewed, with focus on the role of the sympathetic nervous system and the renin-angiotensin-aldosterone system. This review also presents a targeted treatment approach to children with obesity-related hypertension, providing evidence for the recommended therapeutic lifestyle change that should form the basis of any antihypertensive treatment plan in this population of at-risk children. Advantages of specific pharmacologic agents in the treatment of obesity-related hypertension are also reviewed.

Analysis of factors associated with excess weight in school children

Objective:

To determine the prevalence of overweight and obesity in schoolchildren aged 10 to 16 years and its association with dietary and behavioral factors.

Methods:

Cross-sectional study that evaluated 505 adolescents using a structured questionnaire and anthropometric data. The data was analyzed through the T Test for independent samples and Mann-Whitney Test to compare means and medians, respectively, and Chi² Test for proportions. Prevalence ratio (RP) and the 95% confidence interval was used to estimate the degree of association between variables. The logistic regression was employed to adjust the estimates to confounding factors. The significance level of 5% was considered for all analysis.

Results:

Excess weight was observed in 30.9% of the schoolchildren: 18.2% of overweight and 12.7% of obesity. There was no association between weight alterations and dietary/behavioral habits in the bivariate and multivariate analyses. However, associations were observed in relation to gender. Daily consumption of sweets [PR=0.75 (0.64-0.88)] and soft drinks [PR=0.82 (0.70-0.97)] was less frequent among boys; having lunch daily was slightly more often reported by boys [OR=1.11 (1.02-1.22)]. Physical activity practice of (≥3 times/week) was more often mentioned by boys and the association measures disclosed two-fold more physical activity in this group [PR=2.04 (1.56-2.67)] when compared to girls. Approximately 30% of boys and 40% of girls stated they did not perform activities requiring energy expenditure during free periods, with boys being 32% less idle than girls [PR=0.68 (0.60-0.76)].

Conclusions:

A high prevalence of both overweight and obesity was observed, as well as unhealthy habits in the study population, regardless of the presence of weight alterations. Health promotion strategies in schools should be encouraged, in order to promote healthy habits and behaviors among all students.

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.

Diagnosis, Epidemiology, and Management of Hypertension in Children

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

Analysis of factors associated with excess weight in school children

OBJECTIVE

To determine the prevalence of overweight and obesity in schoolchildren aged 10 to 16 years and its association with dietary and behavioral factors.

METHODS

Cross-sectional study that evaluated 505 adolescents using a structured questionnaire and anthropometric data. The data was analyzed through the T Test for independent samples and Mann-Whitney Test to compare means and medians, respectively, and Chi² Test for proportions. Prevalence Ratio (RP) and the 95% confidence interval was used to estimate the degree of association between variables. The logistic regression was employed to adjust the estimates to confounding factors. The significance level of 5% was considered for all analysis.

RESULTS

Excess weight was observed in 30.9% of the schoolchildren: 18.2% of overweight and 12.7% of obesity. There was no association between weight alterations and dietary/behavioral habits in the bivariate and multivariate analyses. However, associations were observed in relation to gender. Daily consumption of sweets [PR=0.75 (0.64-0.88)] and soft drinks [PR=0.82 (0.70-0.97)] was less frequent among boys; having lunch daily was slightly more often reported by boys [OR=1.11 (1.02-1.22)]. Physical activity practice of (≥3 times/week) was more often mentioned by boys and the association measures disclosed two-fold more physical activity in this group [PR=2.04 (1.56-2.67)] when compared to girls. Approximately 30% of boys and 40% of girls stated they did not perform activities requiring energy expenditure during free periods, with boys being 32% less idle than girls [PR=0.68 (0.60-0.76)].

CONCLUSIONS

A high prevalence of both overweight and obesity was observed, as well as unhealthy habits in the study population, regardless of the presence of weight alterations. Health promotion strategies in schools should be encouraged, in order to promote healthy habits and behaviors among all students.

The Role of Obesity in the Development of Left Ventricular Hypertrophy Among Children and Adolescents

Both obesity and hypertension have increased substantially among children over the last several decades. At the same time, mounting evidence has pointed to the role of these and other cardiovascular disease risk factors on the development of end organ damage such as left ventricular hypertrophy in children. While traditionally thought to occur in response to an increased afterload as in systemic hypertension, evidence demonstrates that obesity is associated with left ventricular hypertrophy independent of blood pressure. Both hemodynamic and non-hemodynamic factors contribute to the pathogenesis of obesity-related left ventricular remodeling. However, more contemporary research suggests that adiposity and blood pressure have a greater effect on left ventricular geometry when present together than when present alone. Normalization of left ventricular mass in obese hypertensive individuals requires achievement of both normotension and weight loss. Additional strategies are needed to promote the cardiovascular health of children, with greater emphasis placed on obesity prevention.

Effects of Malnutrition on Left Ventricular Mass in a North-Malagasy Children Population

Background

Malnutrition among children population of less developed countries is a major health problem. Inadequate food intake and infectious diseases are combined to increase further the prevalence. Malnourishment brings to muscle cells loss with development of cardiac complications, like arrhythmias, cardiomyopathy and sudden death. In developed countries, malnutrition has generally a different etiology, like chronic diseases. The aim of our study was to investigate the correlation between malnutrition and left ventricular mass in an African children population.

Methods

313 children were studied, in the region of Antsiranana, Madagascar, with age ranging from 4 to 16 years old (mean 7,8 ± 3 years). A clinical and echocardiographic evaluation was performed with annotation of anthropometric and left ventricle parameters. Malnutrition was defined as a body mass index (BMI) value age- and sex-specific of 16, 17 and 18,5 at the age of 18, or under the 15^th percentile. Left ventricle mass was indexed by height^2.7 (LVMI).

Results

We identified a very high prevalence of children malnutrition: 124 children, according to BMI values, and 100 children under the 15^th percentile. LVMI values have shown to be increased in proportion to BMI percentiles ranging from 29,8 ± 10,8 g/m^2.7 in the malnutrition group to 45 ± 15,1 g/m^2.7 in >95^th percentile group. LVMI values in children < 15^th BMI percentile were significantly lower compared to normal nutritional status (29,8 ± 10,8 g/m^2,7 vs. 32,9 ± 12,1 g/m^2,7, p = 0.02). Also with BMI values evaluation, malnourished children showed statistically lower values of LVMI (29,3 ± 10,1 g/m^2,7 vs. 33,6 ± 12,5 g/m^2,7, p = 0.001).

Conclusion

In African children population, the malnourishment status is correlated with cardiac muscle mass decrease, which appears to be reduced in proportion to the decrease in body size.

Left Ventricular Hypertrophy Phenotype in Childhood-Onset Essential Hypertension

The aim of this study was to determine the risk factors associated with left ventricular (LV) hypertrophy (LVH) among 89 untreated children with primary hypertension. Clinic hypertension was confirmed by 24-hour ambulatory blood pressure (BP) monitoring. LV mass (LVM) index was calculated as LVM (g)/height (m)(2.7) and LVH was defined as LVM index >95th percentile. Children with (n=32) and without (n=57) LVH were compared. Both obesity and systolic BP were independently associated with LVH, with a higher contribution by body mass index. Obesity contributed significantly, with a nearly nine-fold increased risk of LVH. There was evidence of effect modification by the presence or absence of obesity on the relationship between systolic BP and LVH, whereby the relationship existed mainly in nonobese rather than obese children. Hence, to achieve reversal of LVH, clinicians should take into account both BP control and weight management.

Primary hypertension is a disease of premature vascular aging associated with neuro-immuno-metabolic abnormalities

There is an increasing amount of data indicating that primary hypertension (PH) is not only a hemodynamic phenomenon but also a complex syndrome involving abnormal fat tissue distribution, over-activity of the sympathetic nervous system (SNS), metabolic abnormalities, and activation of the immune system. In children, PH usually presents with a typical phenotype of disturbed body composition, accelerated biological maturity, and subtle immunological and metabolic abnormalities. This stage of the disease is potentially reversible. However, long-lasting over-activity of the SNS and immuno-metabolic alterations usually lead to an irreversible stage of cardiovascular disease. We describe an intermediate phenotype of children with PH, showing that PH is associated with accelerated development, i.e., early premature aging of the immune, metabolic, and vascular systems. The associations and determinants of hypertensive organ damage, the principles of treatment, and the possibility of rejuvenation of the cardiovascular system are discussed.

Relationship of ambulatory blood pressure and body mass index to left ventricular mass index in pediatric patients with casual hypertension

Both obesity and hypertension are associated with left ventricular hypertrophy (LVH) in children. Our objective was to compare the prevalence of LVH in obese and nonobese subjects with casual hypertension who underwent ambulatory blood pressure monitoring (ABPM). Untreated children (aged 6-20 years) underwent 24-hour ABPM, and left ventricular mass index (LVMI) was measured. Subjects were classified into three groups: white coat hypertension (WCH), prehypertension (pre-HT), and hypertension (HT). The prevalence of LVH was compared between obese and nonobese subjects among the groups. Of 69 children who underwent ABPM, thirty-two patients (46%) had WCH, 13 (19%) had pre-HT, and 24 (35%) had HT. Mean age, BMI, and LVMI were similar in the groups (P = not significant [NS]). In all, 22 patients (32%) had LVH, with no difference among WCH versus pre-HT versus HT (37.5% vs. 46% vs. 16.7%, P = NS). Twenty-seven subjects (39%) were obese. The ratio of LVH in obese to nonobese was 55.5% to 16.6% (P = .001). In both pre-HT and WCH, patients with LVH had a significantly higher BMI z score (P = .02 and P = .01, respectively). LVMI correlated strongly with BMI z score (P = .0001) but not with any blood pressure parameter. Almost half of children with casual HT have WCH. LVH is prevalent in a third of children with HT, pre-HT, and WCH. In both pre-HT and WCH, patients with LVH were more likely to be obese. More than half of all the obese subjects had LVH. Obese children in all three groups may be at a greater risk for end organ damage.

Association Between Adiposity and Left Ventricular Mass in Children With Hypertension

Left ventricular hypertrophy (LVH) is prevalent among hypertensive children; however, blood pressure (BP) does not predict its presence. The authors conducted a 1-year prospective cohort study to examine the hypothesis that obesity-related risk factors are associated with left ventricular mass index (LVMI) in hypertensive children, and the association between adiposity and LVMI is mediated by BP-dependent and -independent pathways. A total of 49 hypertensive children were enrolled: 51% were overweight/obese and 41% had LVH at baseline. Children overweight/obese at baseline and follow-up had a greater LVMI increase than those of healthy weight at each visit: mean change of 6.4 g/m(2.7) vs 0.95 g/m(2.7) . Baseline body mass index z score was independently associated with LVMI change (β=4.08, 1.54-6.61; P=.002). Only pulse pressure and serum aldosterone partially mediated this relationship. Hypertensive youth manifest multiple cardiovascular disease risk factors that worsen over time despite treatment. Of these, adiposity is most associated with LVH and increasing LVMI.

Development of hypertension in overweight adolescents: a review

The upward trend in adolescent hypertension is widely attributed to the adolescent obesity epidemic. Secular trends in adolescent prehypertension and hypertension have risen in congruence with increasing trends in the prevalence of overweight and obesity. The correlation between body mass index and blood pressure in adolescence is moderate to strong in most studies and strongest in those classified as overweight or obese. The mechanisms relating to the development of hypertension in overweight adolescents are unclear; however, a number of nonmodifiable and modifiable factors have been implicated. Importantly, certain clinical and biochemical markers in overweight adolescents are indicative of high risk for hypertension, including family history of hypertension and hyperinsulinemia. These characteristics may prove useful in stratifying overweight adolescents as high or low risk of comorbid hypertension. The treatment of overweight and obesity related hypertension in this population focuses on two key modalities: lifestyle change and pharmacotherapy. These approaches focus almost exclusively on weight reduction; however, a number of emerging strategies target hypertension more specifically. Among adolescents with overt hypertension there are also several factors that indicate higher risk of concurrent subclinical disease, persistent adult hypertension, and adult cardiovascular disease. This group may benefit substantially from more aggressive pharmacological treatments. Limitations in the literature relate to the paucity of studies reporting specific effects for the adolescent age group of overweight and obese individuals. Nonetheless, intervention for adiposity-related hypertension in adolescence may partially mitigate some of the cardiovascular risk in adulthood.

Is Daytime Systolic Load an Important Risk Factor for Target Organ Damage in Pediatric Hypertension?

The aim of this study was to compare ambulatory blood pressure (BP) monitoring (ABPM) data and determine which hypertension type is a risk factor in target organ damage. A total of 82 children (47 boys) with suspected hypertension based on office BP measurements and considered hypertensive by ABPM were studied. Target organ damage included the following: 35.3% hypertensive retinopathy, 25.6% microalbuminuria, 15.8% increased left ventricular mass index, 29.2% increased carotid intima-media thickness (cIMT), 24.3% high augmentation index (AIx), and 19.5% high pulse wave velocity (PWV). The association between BP load, PWV, and cIMT was statistically significant. There were significant correlations between daytime systolic BP load, PWV, AIx, and cIMT. A statistically significant difference was also detected between nighttime systolic BP load, PWV, and cIMT values and nighttime diastolic BP load levels and values of AIx and cIMT. There was also a statistically significant difference between the high level of nighttime diastolic BP load and cIMT. The authors found that target organ damage was seen more often in children with primary hypertension who had systolic loads.

Hypertension in Young People: Epidemiology, Diagnostic Assessment and Therapeutic Approach

High blood pressure (BP) still remains one of the most relevant cardiovascular risk factors, also due to its persistently high prevalence and growing incidence in the general adult and elderly population. Since almost all hypertension-related cardiovascular complications, mostly including coronary artery disease, myocardial infarction, ischemic stroke, and congestive heart failure, occurred in adult and elderly individuals, evidence on both prevalence and clinical management of hypertension in young individuals are lacking. Therefore, the clinical impact of high BP levels in young populations remains to be explored. In the recent years, the attitude of the scientific community has changed and more attention was devoted to young individuals with hypertension, also in view of the fact that early identification of these subjects may prevent developing of established hypertension in adulthood. In addition, unhealthy lifestyle habits have progressively involved children and adolescents worldwide, thus contributing to further increase the risk of developing hypertension in young individuals. On the basis of these considerations, the present review is aimed at providing a brief reappraisal of the major aspects of hypertension in the young age, as well as at promoting interest and discussion on this important issue.

Hypertension Prevalence, Cardiac Complications, and Antihypertensive Medication Use in Children

OBJECTIVE

To determine the prevalence of hypertension diagnosis in children of US military members and quantify echocardiography evaluations, cardiac complications, and antihypertensive prescriptions in the post-2004 guideline era.

STUDY DESIGN

Using billing data from military health insurance (TRICARE) enrollees, hypertension cases were defined as 2 or more visits with a primary or unspecified hypertension diagnosis during any calendar year or 1 such visit if with a cardiologist or nephrologist.

RESULTS

During 2006-2011, the database contained an average 1.3 million subjects aged 2-18 years per year. A total of 16 322 met the definition of hypertension (2.6/1000). The incidence of hypertension increased by 17% between 2006 and 2011 (from 2.3/1000 to 2.7/1000; P < .001). Hypertension was more common in adolescents aged 12-18 years than in younger children (5.4/1000 vs 0.9/1000). Among patients with hypertension, 5585 (34%) underwent echocardiography. The frequency of annual echocardiograms increased from 22.7% to 27.7% (P < .001). In patients with echocardiography, 8.0% had left ventricular hypertrophy or dysfunction. Among the patients with hypertension, 6353 (38.9%) received an antihypertensive medication.

CONCLUSION

The prevalence of hypertension in children has increased. Compliance with national guidelines is poor. Of pediatric patients with hypertension who receive an echocardiogram, 1 in 12 had identified cardiac complications, supporting the current recommendations for echocardiography in children with hypertension. Less than one-half of children with hypertension are treated with medication.

Cardiovascular target organ damage could have been detected in sustained pediatric hypertension

The aim of this study was to assess sustained hypertension in children and its impact on cardiovascular target organ damage (TOD). Blood pressure (BP) was measured in children in Beijing in 2009. Primary hypertension was diagnosed based on three separate visits. Hypertensive children and normotensive children were followed up in 2011. According to these evaluations, three groups were defined: sustained hypertension, non-sustained hypertension and normotensive. Cardiovascular TOD and metabolic disorders were evaluated using pulse-wave velocity (PWV), carotid intima-media thickness (cIMT), and assessments of left ventricular structure and kidney function. A total of 3032 children aged 9-15 years participated in this survey, of whom 128 were diagnosed with hypertension after three separate BP measurements. Eighty out of 128 (62.5%) hypertensive and 158 normotensive children were available for follow-up in 2011. Forty-eight children were defined as having sustained hypertension, 38 as non-sustained hypertension and 152 as normotensive. Mean levels of brachial-ankle PWV (baPWV), left ventricular mass, left ventricular mass index (LVMI) and cIMT were significantly different between the three groups (p < 0.01). Compared to normotensives, the odds ratios and 95% confidence intervals for elevated LVM and cIMT were 5.27 (1.57-17.66) and 2.88 (1.03-8.09) in the non-sustained hypertensive group, and 3.28 (1.00-10.74) and 7.25 (2.69-19.58) in the sustained hypertensive group. The children with sustained hypertension have the highest risk of developing arterial stiffness, left ventricular hypertrophy and early blood vessel endothelium damage. The indices of cIMT, LVMI and PWV were useful to identify children at high risk of cardiovascular TOD.

Left ventricular mass and diastolic function in obese children and adolescents

BACKGROUND

Our aims were to assess left ventricular structure and diastolic function in obese subjects stratified according to ambulatory blood pressure status, and to investigate independent predictors of the left ventricular mass (LVM) index.

METHODS

Obese subjects aged 9-19 years referred for ambulatory blood pressure monitoring (ABPM) were evaluated in the cross-sectional study. In addition to biochemical and anthropometric measurements, subjects underwent ABPM, Doppler echocardiography, and treadmill exercise test.

RESULTS

According to ABPM results, 103 subjects with obesity (mean age 14.1 ± 2 years) were split in two groups: 49 hypertensive, and 54 without hypertension. Left ventricular hypertrophy was found in 16.3 % of hypertensive, and 5.6 % of normotensive. Variables included in stepwise regression analysis as potential determinants of LVM index were age, body mass index z score, waist circumference, peak systolic blood pressure on exercise test, 24-h heart rate, and night heart rate. Peak systolic blood pressure (adjusted R(2) = 0.051, β = 0.245, p = 0.013) remained as the independent predictor of LVM index. Diastolic function evaluated by mitral E/A ratio was decreased in both obese groups.

CONCLUSIONS

Early markers of cardiac disease including hypertrophy and diastolic dysfunction of the left ventricle are present in youths with obesity prior to the development of sustained hypertension.

Recent clinical and translational advances in pediatric hypertension

Epidemiological reports describe a child population increase in BP level and an increase in prevalence of hypertension, that is largely, but not entirely, driven by a concurrent increase in childhood obesity. Given current estimates, ≈10% of adolescents have hypertension or prehypertension. In addition to obesity, dietary salt intake and waist circumference, a marker of visceral obesity, are found to be independently associated with the rise in BP among children and adolescents. Dietary salt intake in urban children is well above recommended levels largely because of consumption of processed and fast foods. Childhood exposures, such as stress,52 salt, and fructose, as well as lifestyles, including food sources, sleep patterns, and reductions in physical activity may have a role in obesity-high BP associations. In addition, clinical and translational evidence is mounting that intrauterine exposures alter can effect changes in fetal development that have an enduring effect on cardiovascular and metabolic function later in life. These effects can be detected even in children who are products of a term otherwise normal pregnancy. Hypertension in childhood has been defined statistically (BP ≥ 95th percentile) because of lack of outcome data that links a BP level with heightened risk for future cardiovascular events. Therefore, primary hypertension had been considered a risk factor for later hypertension in adulthood. Intermediate markers of TOD, including cardiac hypertrophy, vascular stiffness, and increases in cIMT, are detectable in adolescents with primary hypertension. Evidence that vascular injury is present in the early phase of hypertension and even in prehypertension warrants consideration on the current definition of pediatric hypertension. With further studies on TOD and other risk factors in addition to high BP, it may be possible to shift from a statistical definition to a definition of childhood hypertension that is evidence based. Preventing or reducing childhood obesity would have substantial benefit in countering the documented increase in BP levels and prevalence of high BP in childhood. Weight control in overweight and obese children, along with dietary changes 53 and increases in physical activity,54 has benefit on BP levels in childhood. Prevention of childhood obesity and BP risk will require multiple levels of intervention, including public health, health policy, and attention to food supply to foster the necessary lifestyle changes to prevent and reduce childhood obesity.

Prevalence of metabolic syndrome and obesity-associated hypertension in the racial ethnic minorities of the United States

Metabolic syndrome (MetS) is a clinical condition that includes multiple cardiovascular disease risk factors, including obesity, high blood pressure or hypertension, dyslipidemia, and abnormal glucose metabolism. The core metabolic abnormality in MetS is insulin resistance, or impaired insulin-mediated glucose regulation that results in elevated plasma insulin concentration. MetS greatly increases the risk for diabetes, atherosclerosis, and adverse metabolic and cardiovascular outcomes. The syndrome is present in over 25 % of adults in the U.S., with higher rates among racial/ethnic minority groups. Although commonly associated with adult diseases and aging, MetS has also been described in children and adolescents, but at a much lower prevalence of approximately 4-5 %. Because obesity is a key component of the syndrome, the growing childhood epidemic has raised awareness of MetS in children. The rate of MetS among obese children and adolescents is approximately 30 %, with similar racial/ethnic disparity among minority groups as among adults.

Role of osteoprotegerin and its gene polymorphisms in the occurrence of left ventricular hypertrophy in essential hypertensive patients

The aim of the study was to investigate the role of osteoprotegerin (OPG) in left ventricular hypertrophy (LVH) development in patients with essential hypertension (EH). A total of 1092 patients diagnosed with EH were recruited. The LVHs were determined and OPG gene polymorphisms were genotyped. Patients with LVH had a significantly higher mean serum OPG level than those without LVH. The 1181CC genotype carriers had significantly lower risk for LVH compared with GC and GG genotype carriers. The serum OPG level and OPG 1181 G>C polymorphism were found to be independent risk factors for the occurrence of LVH in hypertensive patients. In vitro study shows that OPG overexpression upregulates cell surface size, protein synthesis per cell, and hypertrophy- and fibrosis-related proteins in both cardiomyocytes and cardiac fibroblasts, whereas OPG inhibition can abolish the above-mentioned changes. Consistent with the in vitro data, our in vivo study revealed that the OPG administration induced the LVH in hypertensive rats. This study is the first to report the close association between OPG and LVH development in EH patients and the regulatory effect of OPG on cardiomyocytes and cardiac fibroblasts.

Fibroblast growth factor-23 in obese, normotensive adolescents is associated with adverse cardiac structure

OBJECTIVES

Fibroblast growth factor-23 (FGF23) is a biomarker for cardiovascular disease. Obesity may promote FGF23 production in the absence of chronic kidney disease. We sought to determine among normotensive African American adolescents whether FGF23 levels are greater in obese compared with normal-weight adolescents and to determine the relationship of FGF23 with markers of cardiac structure and insulin resistance.

STUDY DESIGN

Cross-sectional data were obtained from a cohort of 130 normotensive, African American adolescents ages 13-18 years without chronic kidney disease; 74 were obese; 56 were normal weight. Plasma C-terminal FGF23, fasting glucose and insulin, and high-sensitivity C-reactive protein were measured; participants underwent M-mode echocardiography.

RESULTS

FGF23 was skewed and approximately normally distributed after natural log transformation (logFGF23). FGF23 levels were greater in obese vs normal-weight participants (geometric mean 43 vs 23 RU/mL, P < .01). FGF23 values were significantly greater in participants with eccentric or concentric cardiac hypertrophy compared with those without hypertrophy P < .01). LogFGF23 directly correlated with body mass index, body mass index z-score, waist circumference, fasting insulin levels, and homeostasis model assessment scores. Regression models adjusted for age, sex, and high-sensitivity C-reactive protein suggest that each 10% increase in FGF23 is associated with a 1.31 unit increase in left ventricular mass (P < .01), a 0.29-unit increase in left ventricular mass index (P < .01), and a 0.01-unit increase in left atrial dimension indexed to height (P = .02).

CONCLUSIONS

In this sample of obese African American adolescents, FGF23 blood levels were associated with abnormal cardiac structure. We postulate that FGF23 may be an early marker of cardiac injury in obese but otherwise-healthy African American adolescents.

Screening blood pressure measurement in children: are we saving lives?

Blood Pressure screening in children and adolescents is currently recommended by several prominent medical organizations, including the American Heart Association, the National High Blood Pressure Education Program, the National Heart, Lung, and Blood Institute, the European Society of Hypertension, and the American Academy of Pediatrics. This practice was recently subject to intense scientific review by the U.S. Preventive Services Task Force. The conclusion of the Task Force was that "current evidence is insufficient to assess the balance of benefits and harms of screening for primary hypertension in asymptomatic children and adolescents." This commentary provides an alternate interpretation of current evidence for blood pressure screening in children and adolescents and highlights its importance as a part of routine medical care.

Treatment of obesity-related hypertension in children and adolescents

The obesity epidemic has become a common concern among pediatricians, with an estimated 32 % of US children and adolescents classified as overweight and 18 % as obese. Along with the increase in obesity, a growing body of evidence demonstrates that chronic diseases, such as Type 2 diabetes, primary hypertension, and hyperlipidemia, once thought to be confined solely to adulthood, are commonly seen among the obese in childhood. Following a brief summary of the diagnosis and evaluation of hypertension in obese children and adolescents, this review will highlight recent research on the treatment of obesity-related hypertension. Pharmacologic and non-pharmacologic treatment will be discussed. Additionally, current and emerging therapies for the primary treatment of obesity in children and adolescents, which have been gaining in popularity, will be reviewed.

Effects of obesity and race on left ventricular geometry in hypertensive children

BACKGROUND

Like left ventricular hypertrophy (LVH), abnormal left ventricular (LV) geometry increases cardiovascular risk, but little data utilizing age and sex-specific norms are currently available on LV geometry in hypertensive children.

METHODS

This was a cross-sectional study of 141 hypertensive children aimed at determining the prevalence of LVH and abnormal LV geometry in the patient population and whether clinical characteristics associated with these findings differ by race. LVH was defined as an LV mass index of ≥95th percentile or cardiologist diagnosis. Abnormal geometry was defined as the presence of LVH or a relative wall thickness of >0.41.

RESULTS

The prevalence of LVH was 35 % overall. According to race, LVH prevalence was 49 % among African-Americans (AA) versus 30 % among non-AA (p < 0.05). Overweight/obesity was also highly prevalent among AA compared to non-AA (87 vs. 71 %, respectively; p = 0.03). After multivariable adjustment, the body mass index (BMI) z-score and 95 % diastolic blood pressure (BP) index were the sole independent predictors of LVH. Of the 141 hypertensive children, 40 % had abnormal LV geometry; 63 % among AA vs. 32 % among non-AA (p = 0.001). Multivariable analyses revealed a 3.8-fold increased odds of abnormal geometry among AA (p = 0.002).

CONCLUSIONS

While LVH, abnormal geometry and overweight/obesity are more prevalent among AA hypertensive children, after multivariable adjustment, BMI and race were independently associated with LVH and abnormal geometry, respectively. This result suggests that both race and obesity have important roles in the development of end-organ damage among children with primary hypertension.

Nighttime blood pressure, systolic blood pressure variability, and left ventricular mass index in children with hypertension

BACKGROUND

Nighttime blood pressure (BP) and systolic BP variability on ambulatory blood pressure monitoring (ABPM) have been strongly associated with target-organ damage in hypertensive adults. The clinical relevance of these variables in children with hypertension remains under-studied.

METHODS

The study group included children aged 5-18 years old referred to the outpatient nephrology clinic for an elevated casual BP who underwent an ABPM and echocardiography (ECHO) study and did not have secondary hypertension. The interpretation of ABPM parameters and left ventricular mass index (LVMI) was based on normative references.

RESULTS

Seventy-two children fulfilled the inclusion criteria. The association of various potential predictors including age, BMI z-score, casual BP z-score and ABPM parameters (BP z-score, BP load, nocturnal dipping and BP variability- within-subject standard deviation (SD) of BP) with LVMI was analyzed. On adjusted regression analysis, nighttime systolic BP load [standardized regression coefficient (β) 0.23; p < 0.05] and daytime systolic BP variability (β 0.37; p < 0.05) had significant association with LVMI.

CONCLUSIONS

In children with primary hypertension, nighttime systolic BP load and daytime systolic BP variability had a stronger association with LVMI than casual BP and other ABPM parameters. Future longitudinal studies are needed to establish the causality among these variables.

Echocardiographic indices of left ventricular hypertrophy and diastolic function in hypertensive patients with preserved LVEF classified as dippers and non-dippers

INTRODUCTION

Long-lasting arterial hypertension causes left ventricular hypertrophy (LVH) and impairs left ventricular diastolic function. Our aim was to compare echocardiographic parameters between hypertensive patients defined as dippers and non-dippers during ambulatory blood pressure (BP) monitoring.

MATERIAL AND METHODS

We analysed 61 consecutive subjects with treated hypertension undergoing 24-h BP monitoring and transthoracic echocardiographic examination and included in the study patients with preserved left ventricular ejection fraction (EF ≥ 50%). Echocardiographic and arterial pressure parameters were compared between the group classified as dippers (n = 26, 57 ±13 years, 16 males) and non-dippers (n = 35, 60 ±12 years, 24 males) according to present or absent decrease of BP during the night > 10%. Echocardiographic data were compared between both groups and control subjects without hypertension.

RESULTS

Dippers had lower average systolic, diastolic and mean arterial pressure during the night hours but did not differ according to the mean pressure calculated from a 24-hour period. All echocardiographic parameters were similar in dippers and non-dippers. All patients with arterial hypertension presented with larger dimension of both ventricles and left atrium, thicker left ventricular walls, higher LV mass and mass index and preserved EF and E/A ratio as compared with normotensive controls. Normal geometry, concentric remodelling and eccentric hypertrophy were similarly distributed in both groups. Concentric hypertrophy was more prevalent in non-dippers as compared to the dippers (71.4% vs. 38.5%, p < 0.043).

CONCLUSIONS

The concentric type of LVH is the prevalent pattern in non-dippers. Non-dipping blood pressure pattern may be responsible for the development of left ventricular concentric hypertrophy secondary to hypertension.

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.

Pediatric ambulatory blood pressure monitoring: indications and interpretations

The prevalence of hypertension in children and adolescents is increasing, especially in obese and ethnic children. The adverse long-term effects of hypertension beginning in youth are known; therefore, it is important to identify young patients who need intervention. Unfortunately, measuring blood pressure (BP) is difficult due to the variety of techniques available and innate biologic variation in BP levels. Ambulatory BP monitoring may overcome some of the challenges clinicians face when attempting to categorize a young patient's BP levels. In this article, the authors review the use of ambulatory BP monitoring in pediatrics, discuss interpretation of ambulatory BP monitoring, and discuss gaps in knowledge in usage of this technique in the management of pediatric hypertension.

Ambulatory blood pressure status in children: comparing alternate limit sources

The American Heart Association has included alternate ambulatory blood pressure (ABP) limits for children published by Wühl in 2002. These updated limits employ the same pediatric cohort data as the previous ABP limits published by Soergel in 1997 but differ in analysis technique. The implications of changing ABP limit source on the diagnosis of hypertension has yet to be examined in a large pediatric cohort. We reviewed 741 ABP monitorings performed in children referred to our hypertension clinic between 1991-2007. Hypertension was defined as 24-h mean blood pressure ≥ 95 th percentile or 24-h blood pressure load ≥ 25%, by Soergel and Wühl limits separately. Six hundred seventy-three (91%) children were classified the same by both limit sources. Wühl limits were more likely than Soergel to classify a child as hypertensive (443 vs. 409, respectively). There was an increased classification of prehypertension and decreased white-coat hypertension by the Wühl method, whereas ambulatory and severe hypertension counts remained relatively the same by both limits sources. The use of either limit source will not significantly affect most clinical outcomes but should remain consistent over long-term research projects. Collection of new normative data from a larger, multiethnic population is needed for better measurement of ABP in children.