Characteristics of children with primary hypertension seen at a referral center

Hypertension in children with obesity

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

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.

Blood pressure rhythmicity and visceral fat in children with hypertension

Primary hypertension is associated with disturbed activity of the sympathetic nervous system and altered blood pressure rhythmicity. We analyzed changes in cardiovascular rhythmicity and its relation with target organ damage during 12 months of antihypertensive treatment in 50 boys with hypertension (median, 15.0 years). The following parameters were obtained before and after 12 months of antihypertensive treatment: 24-hour ambulatory blood pressure, left ventricular mass, carotid intima-media thickness, and MRI for visceral and subcutaneous adipose tissue. Amplitudes and acrophases of mean arterial pressure and heart rate rhythms were obtained for 24-, 12-, and 8-hour periods. After 1 year of treatment, 68% of patients were normotensive, and left ventricular mass and carotid intima-media thickness decreased in 60% and 62% of patients, respectively. Blood pressure and heart rate rhythmicity patterns did not change. Changes in blood pressure amplitude correlated with the decrease of waist circumference (P=0.035). Moreover, the decrease of visceral fat correlated with the decrease of 24-hour mean arterial pressure and heart rate acrophases (both P<0.05). There were no differences in changes of blood pressure and heart rate rhythms between patients who achieved or did not achieve normotension and regression of left ventricular mass and carotid intima-media thickness. It was concluded that abnormal cardiovascular rhythmicity persists in children with primary hypertension despite effective antihypertensive treatment, which suggests that it may be the primary abnormality. The correlation between changes in cardiovascular rhythmicity and visceral obesity may indicate that the visceral fat plays an important role in the sympathetic activity of adolescents with hypertension.

Primary hypertension in children and adolescents is an immuno-metabolic disease with hemodynamic consequences

With the rise in obesity epidemic primary hypertension (PH) is now one of the most common chronic diseases in adolescence. In contrast to hypertensive adults, hypertensive children usually are not exposed to other comorbidities such as diabetes, chronic kidney disease and atherosclerosis. Thus, PH in children and adolescents can be treated as the early stage of development of cardiovascular disease. There is increasing amount of data indicating that PH is not only hemodynamic phenomenon but a complex syndrome involving disturbed activity of sympathetic nervous system, metabolic abnormalities and activation of innate and adaptive immune system. We discuss results of the studies on clinical, metabolic and immunological phenotype of hypertensive children, associations between metabolic and immunological abnormalities with target organ damage and results of antihypertensive treatment.

Ambulatory Blood Pressure Monitoring in a Cohort of Children Referred with Suspected Hypertension: Characteristics of Children with and without Attention Deficit Hyperactivity Disorder

Childhood hypertension's increasing prevalence has generally been linked to the obesity epidemic. We observed that a significant proportion of children referred to our pediatric center with documented office hypertension are nonobese and have a history of attention deficit hyperactivity disorder (ADHD). To define the extent of this anecdotal observation, we performed a retrospective analysis of ambulatory blood pressure monitoring (ABPM) tests which in our center are routinely performed in newly referred children suspected of hypertension. Twenty-one percent (48 of 227 new referrals) had a history of ADHD, and 81% of them were treated with psychostimulant medications at the time of their ABPM test. Children in this group had a significantly lower average BMI z-score compared with the rest of the children (0.18 versus 0.75) and were significantly more likely to have abnormally elevated wake systolic loads on ABPM (38% versus 4%). The overall proportion of children with any abnormality on ABPM was comparable in both groups (46% versus 40%). Conclusion. A significant proportion of children suspected of hypertension have ADHD which may be related to higher wake systolic BP values. The prevalence of hypertension among children with ADHD will have to be determined in prospective studies.

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

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

Focus on prevention, diagnosis and treatment of hypertension in children and adolescents

The European Society of Hypertension has recently published its recommendations on prevention, diagnosis and treatment of high blood pressure in children and adolescents. Taking this contribution as a starting point the Study Group of Hypertension of the Italian Society of Pediatrics together with the Italian Society of Hypertension has conducted a reappraisal of the most recent literature on this subject. The present review does not claim to be an exhaustive description of hypertension in the pediatric population but intends to provide Pediatricians with practical and updated indications in order to guide them in this often unappreciated problem.

This document pays particular attention to the primary hypertension which represents a growing problem in children and adolescents. Subjects at elevated risk of hypertension are those overweight, with low birth weight and presenting a family history of hypertension. However, also children who do not present these risk factors may have elevated blood pressure levels. In pediatric age diagnosis of hypertension or high normal blood pressure is made with repeated office blood pressure measurements that show values exceeding the reference values. Blood pressure should be monitored at least once a year with adequate methods and instrumentation and the observed values have to be interpreted according to the most updated nomograms that are adjusted for children’s gender, age and height. Currently other available methods such as ambulatory blood pressure monitoring and home blood pressure measurement are not yet adequately validated for use as diagnostic instruments. To diagnose primary hypertension it is necessary to exclude secondary forms. The probability of facing a secondary form of hypertension is inversely proportional to the child’s age and directly proportional to blood pressure levels. Medical history, clinical data and blood tests may guide the differential diagnosis of primary versus secondary forms. The prevention of high blood pressure is based on correct lifestyle and nutrition, starting from childhood age. The treatment of primary hypertension in children is almost exclusively dietary/behavioral and includes: a) reduction of overweight whenever present b) reduction of dietary sodium intake c) increase in physical activity. Pharmacological therapy will be needed rarely and only in specific cases.

White coat hypertension in children: not rare and not benign?

The clinical significance of white coat hypertension (WCH) remains uncertain. We aimed to evaluate the target organ damage (TOD) in children with essential hypertension (HTN) and WCH. We retrospectively analyzed the body mass index (BMI) and ambulatory blood pressure monitoring (ABPM) in 183 untreated children aged 5 to 19 years who were referred for assessment of hypertension and had secondary hypertension ruled out. Left ventricular mass index (LVMi) and carotid intima media thickness (CIMT) were analyzed in a subset of 106 children. WCH was found in 54/183 children (29.5%) who had normal mean arterial pressure (MAP), MAP load, and MAP day/night ratio. However, the mean+/-SD LVMi (g/m(2.7)) was identical in HTN and WCH patients (38.2+/-10.9 vs. 37.0+/-11.3, P=.59); it exceeded the 95th percentile in 40% HTN and 36% WCH patients (NS). The mean CIMT was significantly higher compared with normal, but not different between HTN and WCH; it exceeded the 95th percentile in 26% HTN and 29% WCH patients. WCH was found in up to 30% of children referred for HTN. Patients with WCH have TOD comparable to that found in HTN patients despite similar BMI, significantly lower average BP and BP load and a well-preserved BP dipping pattern.

Clinical and demographic characteristics of children with hypertension

Most information describing hypertension in the young comes from single-center reports. To better understand contemporary demographic and clinical characteristics of hypertensive children and adolescents, we examined baseline data on 351 children aged 1 to <17 years old who were enrolled in 2 multicenter trials of valsartan. Anthropometric, laboratory, and demographic information at randomization was extracted from the clinical trials databases. Summary variables were created and compared for 3 age groups: <6 years (n=90), 6 to <12 years (n=131), and 12 to <17 years (n=130). Comparisons were also made between different etiologies of hypertension and for different anthropometric categories. Children<6 years old were significantly more likely to have secondary hypertension and were significantly less likely to have weight or body mass index>95 percentile compared with older children. Estimated glomerular filtration rate was significantly lower in children<6 years old (90.9±31.8 mL/min per 1.73 m2) than in the other 2 age groups (6 to <12 years, 141.4±42.1 mL/min per 1.73 m2; 12 to <17 years, 138.3±46.0 mL/min per 1.73 m2). Frequency of total cholesterol>95 percentile was significantly lower in children aged<6 years. Diastolic blood pressure index (subject blood pressure÷95 percentile) was significantly higher in children<6 years old (1.1 versus 1.0 in both the 6 to <12 years and 12 to <17 years groups; both P<0.0001). We conclude that hypertensive children<6 years are more likely to have secondary hypertension and to have higher diastolic blood pressure and lower glomerular filtration rate and are less likely to be obese or to have elevated cholesterol than school-aged children or adolescents. These findings emphasize unique aspects of childhood hypertension that should be considered when evaluating children and adolescents with elevated blood pressure and in designing future clinical trials.

Hypertension and obesity: epidemiology, mechanisms and clinical approach

Obesity-related hypertension in pediatric patients is becoming more prevalent around the world as a consequence of the childhood obesity epidemic. Hypertension and the metabolic abnormalities associated with obesity will significantly increase the health risks for these children as they grow into adulthood. The pathophysiology of obesity-related hypertension is complex, and multiple potential mechanisms likely contribute to the development of higher blood pressure in obese children. These include hyperinsulinemia, activation of the renin-angiotensin-aldosterone system, stimulation of the sympathetic nervous system, abnormalities in adipokines such as leptin, direct effects of perinephric fat on the renal parenchyma, and cytokines acting at the vascular endothelial level. As in any child with elevated blood pressure, diagnostic evaluation should focus on confirmation of hypertension, determine if an underlying cause can be identified and whether hypertensive target organ damage is present. Therapy should begin with lifestyle modifications, but will often need to include one or more antihypertensive medications.

Prediction of primary vs secondary hypertension in children

Despite current guidelines, variability exists in the workup of hypertensive children due to physician preferences. The study evaluates primary vs secondary hypertension diagnosis from investigations routinely performed in hypertensive children. This retrospective study included children 5 to 19 years with primary and secondary hypertension. The proportions of abnormal laboratory and imaging tests were compared between primary and secondary hypertension groups. Risk factors for primary vs secondary hypertension were evaluated by logistic regression and likelihood function analysis. Patients with secondary hypertension were younger (5-12 years) and had a higher proportion of abnormal creatinine, renal ultrasound, and echocardiogram findings. There was no significant difference in abnormal results of thyroid function, urine catecholamines, plasma renin, and aldosterone. Abnormal renal ultrasound findings and age were predictors of secondary hypertension by regression and likelihood function analysis. Children aged 5 to 12 years with abnormal renal ultrasound findings and high diastolic blood pressures are at higher risk for secondary hypertension that requires detailed evaluation.

Management of hypertension in the young: role of antihypertensive medications

Traditionally, antihypertensive medications were used in few children or adolescents, usually just those with underlying renal or other organ system disease. However, with recent data suggesting that the incidence of primary hypertension may be increasing in the young, it is possible that more children and adolescents will be prescribed antihypertensive agents. This article will review currently available pediatric data on the use of calcium channel blockers, agents affecting the renin-angiotensin-aldosterone system and other classes of antihypertensive medications in children, highlighting appropriate indications and safety considerations. Guidelines for use of antihypertensive medications, including choice of initial agent and how to prescribe appropriately, will be presented.

Prediabetes and blood pressure effects on heart rate variability, QT-interval duration, and left ventricular hypertrophy in overweight-obese adolescents

This ancillary, descriptive correlational study examined the effect of glucose regulation, blood pressure (BP), and their combined effects on cardiac autonomic function in 128 overweight-obese 11-18-year-olds. Measures included body mass index, resting BP, fasting glucose, glucose tolerance, and cardiac autonomic function (heart rate variability, QT, and Cornell voltage). After adjusting for age and gender, multivariate analysis of covariance revealed no differences in cardiac autonomic measures based on glucose regulation (p = .319), BP (p = .286), or the interaction between glucose regulation and BP (p = .132). The additive effect of prediabetes and elevated BP did not impact cardiac autonomic function in overweight-obese youth.

Primary hypertension and special aspects of hypertension in older children and adolescents

The prevalence of hypertension has increased at an accelerated rate in older children and adolescents. This has raised great concern about premature development of cardiovascular disease, which has major long-term health and financial implications. While obesity and sedentary habits largely explain this phenomenon, there are other social and cultural influences that may unmask genetic susceptibility to hypertension in the pediatric population. While it is essential to exclude numerous causes of secondary hypertension in every child, these disorders are not discussed in this review. Rather, the aim of this review is to familiarize pediatricians with casual and ambulatory blood pressure measurement, epidemiology, pathophysiology, and management of several common conditions that play a role in the development of hypertension in children and adolescents. Besides primary hypertension and obesity-related hypertension, emphasis is given to epidemiology, measurement of blood pressure, including ambulatory blood pressure monitoring, hypertension associated with drug use, teenage pregnancy, and video and computer games. Lastly, because pediatricians are increasingly confronted with special issues concerning the management of the hypertensive athlete, this topic is also addressed.

Cardiac and vascular consequences of pre-hypertension in youth

Hypertension is associated with increased left ventricular mass (LVM) and carotid intima-media thickness (cIMT), which predict cardiovascular (CV) events in adults. Whether target organ damage is found in pre-hypertensive youth is not known. The authors measured body mass index, blood pressure, fasting glucose, insulin, lipids and C-reactive protein, LVM/height(2.7) (LVM index), diastolic function, cIMT, carotid stiffness, augmentation index, brachial artery distensibility, and pulse wave velocity (PWV) in 723 patients aged 10 to 23 years (29% with type 2 diabetes mellitus). Patients were stratified by blood pressure level (normotensive: 531, pre-hypertensive: 65, hypertensive: 127). Adiposity and CV risk factors worsened across blood pressure group. There was a graded increase in cIMT, arterial stiffness, and LVM index and decrease in diastolic function from normotension to pre-hypertension to hypertension. In multivariable models adjusted for CV risk factors, status as pre-hypertension or hypertension remained an independent determinant of target organ damage for LVM, diastolic function, internal cIMT, and carotid and arterial stiffness. Pre-hypertension is associated with cardiovascular target organ damage in adolescents and young adults.

Obesity hypertension in adolescents: epidemiology, evaluation, and management

The prevalence of hypertension among all adolescents is approximately 3.5%, with somewhat higher rates of prehypertension. Obesity affects approximately 20% of adolescents in the United States, and the prevalence of hypertension is much higher among obese adolescents compared with nonobese adolescents. As in other populations, the evaluation of elevated blood pressure in obese adolescents should begin with a confirmation of the blood pressure elevation, followed by a focused diagnostic work-up to detect possible secondary causes of hypertension. Primary therapy for obesity-related hypertension in adolescents begins with weight loss, and may include antihypertensive medications if target-organ damage or other indications for drug therapy are present. The emphasis of management should be reduction of future cardiovascular risk.

Primary versus secondary hypertension in children followed up at an outpatient tertiary unit

Childhood hypertension has classically been recognized as a secondary disease. However, primary hypertension also occurs in children. The aim of this study was to compare clinical features of pediatric patients with elevated blood pressure, which were referred to an outpatient tertiary unit, and to detect variables associated with the identification of primary hypertension. The records of 220 patients with hypertension followed between 1996 and 2006 were analyzed. The variable of interest was primary hypertension. Logistic regression analysis was applied to identify clinical variables that were independently associated with primary hypertension. Of 220 patients, 33 (15%) had primary hypertension, and 187 (85%) exhibited secondary hypertension. No statistically significant differences were detected in gender, race, age at diagnosis, and systolic/diastolic blood pressure levels between both groups. After adjustment, four variables at baseline remained independently associated with primary hypertension: absence of signs/symptoms (OR 18.87, 95% CI 6.32-56.29), normal serum creatinine (OR 0.02, 95% CI 0.00-0.27), family history of hypertension (OR 3.03, 95% CI 1.04-8.79), and elevated body weight (OR 1.06, 95% CI 1.02-1.10). The absence of signs/symptoms, normal serum creatinine, family history of hypertension, and overweight/obesity at admission are clues to diagnose primary hypertension in childhood.

Change in left ventricular geometry during antihypertensive treatment in children with primary hypertension

The pattern of the left ventricle (LV) has important significance in adults with hypertension. The aim of the present study was to analyze changes and determinants of LV geometry after 1 year of antihypertensive treatment in children with primary hypertension (PH) in relation to metabolic abnormalities and anthropometrical parameters. In 86 children (14.1 ± 2.4 years) with newly diagnosed PH, LV geometry and biochemical parameters before and after 12 months of standard antihypertensive therapy were assessed. At baseline, normal LV geometry (NG) was found in 42 (48.9%), concentric remodeling (CR) in 4 (4.6%), concentric hypertrophy (CH) in 8 (9.3%), and eccentric hypertrophy (EH) in 32 (37.2%) patients. The prevalence of NG in patients with severe hypertension was significantly lower than in patients with ambulatory hypertension. There were no differences in dipping status in relation to LV geometry. Patients with CH and EH were more viscerally obese than patients with NG. Patients with CH had higher diastolic blood pressure in comparison with EH patients (p < 0.05). The main predictor of relative wall thickness (RWT) was the triglycerides to high density lipoprotein cholesterol (TG/HDL) ratio (R(2 ) = 0.319, β = 0.246, p = 0.004). Patients received 12 months of antihypertensive treatment, either lifestyle modification only (n = 37) or lifestyle modification plus antihypertensive medications (n = 49) if severe ambulatory hypertension or target organ damage were present. After 12 months of treatment the prevalence of EH (37.2% vs 18.6%, p = 0.003) decreased but prevalence of CH did not change. Patients in whom RWT decreased also decreased waist circumference and TG/HDL; the main predictor of RWT decrease was a decrease of the TG/HDL ratio (β = 0.496, R (2) = 0.329, p = 0.002). In adolescents with PH, LV geometry is related to central obesity and insulin resistance. Decrease of abdominal obesity and insulin resistance are the most important predictors of normalization of LV geometry, however CH has lower potential to normalize LV geometry.

Racial differences among children with primary hypertension

OBJECTIVE

Race is a known risk factor for hypertension and cardiovascular disease in adults and influences blood pressure (BP) in children. We sought to determine if there are differences in clinical, laboratory, or echocardiographic characteristics among children with primary hypertension from different racial groups.

PATIENTS AND METHODS

Study participants were 184 children aged 3 to 20 years with a diagnosis of primary hypertension who were examined at 1 of 3 participating centers at the time of initial evaluation of elevated BP. Black children were categorized as African American (AA) and nonblack children as non-AA. Comparisons were made for the entire group and after stratification according to age (<13 or ≥ 13 years).

RESULTS

Overall, children categorized as AA had a higher prevalence of overweight/obesity and left ventricular hypertrophy and had higher plasma renin activity than children who were categorized as non-AA. After age stratification, these differences remained only in the children younger than 13 years old; there were no differences in these findings among children aged 13 years or older. AA children who were aged 13 years or older, however, had higher BPs for both casual and ambulatory measurements. Specifically, they had higher casual diastolic BP, higher 24-hour diastolic BP, higher daytime systolic and diastolic BP, and higher BP loads at night and over a 24-hour period compared with non-AA children who were aged 13 years or older.

CONCLUSIONS

These data indicate that black children with primary hypertension may be at increased cardiovascular risk compared with nonblack children with primary hypertension. However, the high prevalence of overweight/obesity and left ventricular hypertrophy in all youth with primary hypertension demonstrates the need for greater preventive and therapeutic efforts aimed at reducing cardiovascular risk in this vulnerable population.

Inflammatory activation in children with primary hypertension

Low-grade inflammation plays a role in the pathogenesis of primary hypertension (PH) and target organ damage (TOD). We evaluated the profile of inflammatory mediators (CRP, RANTES, MIP-1beta, MIP-1alpha, MCP-1, IL-6, angiogenin, adiponectin) in 30 healthy children (12.7 +/- 3.3 years) and 44 patients with untreated PH (13.7 +/- 2.7 years; n.s). Patients had greater concentrations of CRP, MIP-1beta, and RANTES than controls (all p < 0.05). Children with metabolic syndrome (MS) had greater CRP than children without MS (p = 0.007) and CRP correlated with number of MS criteria, body mass index (BMI), visceral fat, deep subcutaneous fat assessed by magnetic resonance imaging, carotid intima-media thickness (cIMT), left ventricular mass index, and markers of oxidative stress. RANTES correlated with cholesterol, LDL cholesterol, ApoB, and ApoB/ApoA1. Angiogenin correlated with BMI, waist circumference, visceral fat, uric acid, and patients with cIMT>2SD had greater concentration of angiogenin than those with normal cIMT (p = 0.03). Adiponectin was lower in patients with cIMT>2SD than in those with normal cIMT (p = 0.02). No model explaining variability of TOD has been built. Elevated RANTES and MIP-1beta and normal IL-6 and TNF-alpha levels indicate a vascular inflammatory process. Lack of correlation between CRP and chemokines suggests that vascular inflammation in PH precedes the systemic inflammatory changes.

Complications of obesity in children and adolescents

The increasing prevalence and severity of obesity in children and adolescents has provided greater emphasis on the wide variety of comorbid conditions and complications that can be experienced as a consequence of obesity. These complications can occur both in the short term and in the long term. Some complications, earlier thought to be long-term issues, which would only occur in adulthood, have now been shown to occur in children and adolescents. These findings have raised concerns about the overall health experience of those who develop obesity early in life and have even raised questions about whether the obesity epidemic might shorten the life span of the current generation of children. In this paper, I will examine current knowledge regarding the different organ systems that may be impacted by childhood obesity.

Altered cardiovascular rhythmicity in children with white coat and ambulatory hypertension

Adults with ambulatory hypertension or white coat hypertension (WCH) display abnormal cardiovascular rhythms. We studied cardiovascular rhythms by Fourier analysis of 24-h ambulatory blood pressure (BP) measurement profiles in 129 hypertensive children, 54 children with WCH, and 146 age-, height-, and gender-matched healthy subjects. The day/night mean arterial pressure ratio was lower in hypertensive and patients with WCH compared with controls (1.13 versus 1.16 versus 1.21, respectively; p < 0.0001). Eighty-five percent of controls were dippers compared with 74% of WCH (n.s.) and 64% of patients with ambulatory hypertension (p < 0.0001). The prevalence of 24-h rhythms was similar among the groups, but prevalence of 12-h BP rhythms was increased in hypertensive (67%) and WCH (72%) compared with controls (51%, p < 0.0001). The amplitudes of the 24-, 8-, and 6-h BP rhythms were reduced in hypertensive and WCH compared with controls (p < 0.05). Hypertensive and patients with WCH displayed delayed 24-, 12-, 8-, 6-h acrophases in comparison with controls (p < 0.05). In conclusion, hypertensive children exhibit abnormal cardiovascular rhythmicity compared with controls, especially a higher prevalence of nondipping compared with normotensive children. Abnormalities in patients with WCH are intermediate between healthy children and patients with ambulatory hypertension.

Blood pressure in children and target-organ damage later in life

The aim of this study was to examine the association between blood pressure (BP) in children and adolescents and cardiovascular and renal disease in adulthood. This was a retrospective study on patients <18 years of age with an elective admission to Landspitali University Hospital in Reykjavik, Iceland, between 1950 and 1967. We recorded baseline variables including BP and invited all patients for a follow-up visit in 2008 for repeat studies. We used chi(2), Fisher's exact test, and logistic regression to examine the association between BP in childhood and outcome variables at follow-up. We identified 126 individuals (54 men) for the study. The median age (range) at childhood admission was 15 (10-17) years and the median BP was 125/80 mmHg. Median age at follow-up was 58 (42-68) years, follow-up time 43 (25-52) years, and median BP 133/75 mmHg. Eleven had died (five men) and 49 had been diagnosed with hypertension (23 men) and 12 with coronary artery disease (ten men). There was a significant correlation between the diagnosis of coronary artery disease at follow-up and childhood systolic BP (odds ratio = 1.052; P = 0.03) as well as systolic BP >/= 95th percentile (P = 0.03). Our results suggest that elevated childhood systolic BP may increase the risk of coronary artery disease in adult life. The sample size is a limiting factor, and the study should be carried out in a larger population.

International comparison of blood pressure and BMI values in schoolchildren aged 11-16 years

AIMS

This study comprised part of a larger cross-sectional survey performed in Hungary in the period 2005-2006, which was designed first to reveal the representative age-, gender- and height-specific percentile values for the systolic blood pressure (SBP) and the diastolic blood pressure (DBP) in Hungarian children aged 11-16 years. The second aim was to determine the prevalence of overweight and obesity.

METHODS

Analyses were performed on 14,290 Hungarian children aged 11-16 years. All blood pressure (BP) measurements were made with a validated, automated, digital device. The criteria recommended by international guidelines were used.

RESULTS

The prevalence of overweight and obesity among the Hungarian children was found to be 23.4% (3347 adolescents; International Obesity Task Force criteria). Previous studies have reported that the strongest correlation is observed between the BP values and weight, and our results are in accordance with this.

CONCLUSIONS

Regional differences in morphometry (different prevalences of overweight and obesity) and the genetic background, disparate eating habits and other cultural factors may account for the differences in BP levels during childhood. As the prevalence of overweight and obesity is increasing worldwide, it is important that countries carefully monitor the weight and BP status of their children and adolescents.

Assessment and management of hypertension in children and adolescents

The epidemic of overweight and obesity in youth is increasing the prevalence of prehypertension and hypertension among children and adolescents. The younger the child is at presentation and the more severe the blood pressure abnormality, the more likely a secondary cause of hypertension is to be present. Measurement of blood pressure in children requires adaptation to the age and size of the child. Interpretation must be related to normative values specific for age, sex, and height. Evaluation is primarily aimed at identifying secondary causes of hypertension, associated comorbidities, additional risk factors, and evidence of target-organ damage. Ambulatory blood pressure monitoring is emerging as a useful tool for evaluation of some patients, particularly for those with suspected 'white coat' hypertension. Management of prehypertension and hypertension is directed at the underlying cause, exacerbating factors, and the magnitude of the blood pressure abnormality. Healthy behavioral changes are a primary management tool for treating hypertension and, more particularly, prehypertension and for addressing other cardiovascular risk factors, such as obesity. Pharmacological management is reserved for patients with hypertension who do not respond to behavioral changes, have additional cardiovascular risk factors or diabetes, are symptomatic, or have developed target-organ damage.

Regression of target organ damage in children and adolescents with primary hypertension

We assessed the effects of 12 months of non-pharmacological and pharmacological therapy on 24-h ambulatory blood pressure, regression of target organ damage (TOD) and metabolic abnormalities in 86 children (14.1 ± 2.4 years) with primary hypertension. Twenty-four hour systolic and diastolic blood pressure (BP) decreased (130 ± 8 vs 126 ± 8, 73 ± 7 vs 70 ± 7, p = 0.0001 and 0.004 respectively). Body mass index (BMI) did not change, but waist-to-hip (0.85 ± 0.07 vs 0.83 ± 0.05, p = 0.01) and waist-to-height ratio (WHtR; 0.49 ± 0.07 vs 0.48 ± 0.05, p = 0.008) decreased. Left ventricular mass index (LVMi; 38.5 ± 10.7 vs 35.2 ± 7.5 g/m(2.7), p = 0.0001), prevalence of left ventricular hypertrophy (46.5% vs 31.4%; p = 0.0001), carotid intima-media thickness (cIMT; 0.44 ± 0.05 vs 0.42 ± 0.04 mm, p = 0.0001), wall cross sectional area (WCSA; 7.5 ± 1.3 vs 6.9 ± 1.2 mm(2), p = 0.002), hsCRP (1.1 ± 1.0 vs 0.7 ± 0.7 mg/l, p = 0.002), and LDL-cholesterol (115 ± 33 vs 107 ± 26 mg/dl, p = 0.001) decreased. Patients who had lowered BP had a lower cIMT at the second examination (0.41 ± 0.04 vs 0.43 ± 0.04 mm, p = 0.04) and lower initial hsCRP values (0.9 ± 0.7 vs 1.5 ± 1.3 mg/l, p = 0.04) in comparison to non-responders. Regression analysis revealed that the main predictor of LVMi decrease was a decrease in abdominal fat expressed as a decrease in waist circumference (WC) (R (2) = 0.280, β = 0.558, p = 0.005), for WCSA-SDS a decrease in WC (R (2) = 0.332, β = 0.611, p = 0.009) and for a cIMT-SDS decrease the main predictor was a decrease in hsCRP concentrations (R (2) = 0.137, β = 0.412, p = 0.03). Standard antihypertensive treatment lowered BP and led to regression of TOD in hypertensive children. Lean body mass increase and decrease in abdominal obesity correlated with TOD regression.

Blood aldosterone-to-renin ratio, ambulatory blood pressure, and left ventricular mass in children

OBJECTIVE

To assess the blood aldosterone-to-renin ratio (ARR) and its relationship to ambulatory blood pressure (ABP) and left ventricular mass (LVM) in children.

STUDY DESIGN

A cross-sectional clinical study was conducted in 102 children (71.6% African American; 62.7% male) ranging in age from 7 to 18 years (mean, 13.6 years; median, 14 years). ABP (24-hour monitoring) was expressed as blood pressure index (BPI; mean blood pressure/95th percentile by sex and height). LVM was measured by echocardiography and expressed as an index (LVMI = g/height [m](2.7)). Regression analyses were used to estimate associations.

RESULTS

African-American children had significantly lower serum aldosterone concentration and plasma renin activity compared with European-American children (aldosterone: 5.9 ng/dL vs 11.4 ng/dL, P < .0001; renin: 1.6 ng/mL/hour vs 2.8 ng/mL/hour, P = .01). However, ARR was not significantly different by race. ARR was not associated with 24-hour ABP but was significantly associated with LVMI (beta = 0.4 g/m(2.7); P = .02) after adjustment for the ratio of 24-hour urine Na to creatinine excretion, body mass index z- score, and ABP index.

CONCLUSIONS

The data indicated a significant association between ARR and LVMI, but not ABP, in children, suggesting early cardiac remodeling associated with a high ARR.

Blood pressure load, proteinuria and renal function in pre-hypertensive children

It is as yet unclear whether blood pressure load (BPL) can affect renal function in pre-hypertensive children. We have studied 250 children, with a mean age of 9.12 +/- 3.28 years, with the aim of assessing if pre-hypertension in children can indeed affect renal function. The study cohort consisted of 146 children with pre-hypertension (group P) and a control group of 104 children with normal blood pressure (group C). All children were tested for orthostatic proteinuria, an exclusion criterion, glomerular filtration rate (GFR), and proteinuria, and ambulatory blood pressure monitoring was performed. Based on the BPL, group P was further subdivided into group P1 (BPL <or= 40%, low BPL) and group P2 (BPL > 40%, high BPL). We found that GFR was reduced in pre-hypertensive children (90.74 +/- 48.69 vs. 110.32 +/- 20.30 ml/min per 1.73 m(2), p < 0.0001) and that proteinuria was increased (145.36 +/- 110.91 vs. 66.84 +/- 42.94 mg/m(2) per 24 h; p < 0.0001). However, mean values were still within normal limits. A comparison of the group with high BPL and that with low BPL revealed that the former had relatively reduced GFR (79.15 +/- 42.04 vs. 96.78 +/- 51.20 ml/min per 1.73 m(2); p < 0.006) and increased proteinuria (198.29 +/- 142.17 vs. 118.31 +/- 80.07 mg/m(2) per 24 h; p < 0.036). In comparison to the reference values of the normal population, the GFR was reduced and proteinuria was increased in the group with high BPL. Based on our results, pre-hypertension in children with high BPL seems to be associated with reduced GFR and increased proteinuria. A reasonable doubt remains that the patients with higher proteinuria and larger reduction of GFR may harbor an as yet unknown subclinical renal condition responsible for the onset of pre-hypertension. Therefore, children with even mildly elevated BP are at risk of developing renal damage and should change their lifestyle to prevent further increases in BP.

Intima-media thickness measurements in children with cardiovascular risk factors

Measuring intima-media thickness (IMT) is now a standard diagnostic procedure in assessing cardiovascular risk and hypertensive target-organ damage (TOD) in adults. There is also an increasing number of pediatric publications evaluating IMT in children from high-risk groups, such as those with arterial hypertension, diabetes, chronic kidney disease, obesity, dyslipidemia, and homocystinurias. It has been shown that carotid IMT is strongly related with other markers of TOD in children with arterial hypertension and with metabolic cardiovascular risk factors. In children with coarctation of the aorta, carotid IMT correlated both with blood pressure and even with mild residual aortic gradient. On the other hand, studies in children with high cardiovascular risk have shown that normalization of blood pressure and metabolic abnormalities led to regression of arterial changes and decrease of IMT. Although not yet accepted as standard pediatric procedure, IMT measurement is emerging as a promising method of assessing TOD and cardiovascular risk and monitoring treatment efficacy. From a practical point of view, clinical utility of IMT measurements seems to be similar to use of echocardiography in assessing left ventricular mass. However, IMT measurements in children and adolescents should be standardized to avoid bias caused by the use of different measurement methods.

Pediatric hypertension: recent trends and accomplishments, future challenges

Publication of the Fourth Report on high blood pressure (BP) in children and adolescents by the National High BP Education Program (NHBPEP) in 2004 has been followed by a remarkable increase in interest in pediatric hypertension. New data have emerged on the epidemiology of hypertension in the young, the influence of the childhood obesity epidemic on BP, how ambulatory BP monitoring (ABPM) can be used in evaluating elevated BP and the extent of hypertensive target-organ damage in the pediatric age group. Exciting new information on drug treatment of pediatric hypertension has been produced by industry-sponsored clinical trials of antihypertensive medications spurred by the FDA Modernization Act (FDAMA) and successor legislation. Despite these trends, recognition of elevated BP in children and adolescents by primary care providers remains problematic. This article will highlight these and other aspects of pediatric hypertension, hopefully providing a snapshot of where we are in early 2008, and pointing out areas where further work is needed in order to reduce the future burden of adult cardiovascular disease.

Different BMI cardiovascular risk thresholds as markers of organ damage and metabolic syndrome in primary hypertension

Obesity is the main intermediate phenotype of primary hypertension (PH), and increased fat mass is directly related to target organ damage (TOD) and metabolic syndrome (MS). The aim of the study was to assess the sensitivity and specificity of body mass index (BMI), percentile-based, definitions of obesity [BMI > 95th percentile (pc)], and overweight (BMI > 85th pc), and BMI thresholds for cardiovascular (cv) complications (BMIcv) described by Katzmarzyk et al. (Pediatrics 114:198-205, 2004) in predicting risk of TOD and MS in 122 adolescents with PH. Our results indicated that the prevalence of left ventricular hypertrophy (LVH) and carotid intima-media thickness (cIMT) above 2 standard deviations (SDS) was the same, irrespective of the criteria used. BMIcv was more sensitive as a marker of LVH than were the cut-off values of the 85th pc and 95th pc of BMI (87.5%, 75%, 62.5%, respectively; P < 0.0001). BMIcv thresholds and cut-off values of the 85th pc of BMI were of the same sensitivity in predicting the presence of MS (95.8% and 95.8%, respectively) and were more sensitive than the cut-off values of the BMI 95th pc (87.5%; P = 0.02). Metabolic abnormalities, including insulin resistance, were more marked in patients with greater BMI, irrespective of cut-off value. However, only when a stratification system using the 85th pc of BMI was used, were the differences significant for a homoeostasis model assessment for insulin resistance (HOMA-IR) and for serum concentrations of high-density lipoprotein (HDL)-cholesterol, triglycerides and adiponectin. We concluded that BMIcv is more sensitive for diagnosing the presence of LVH and that the cut-off value of the 85th pc of BMI is more sensitive for predicting presence of MS in children with PH.

The frequency of elevated blood pressure in obese minority youth

In this study, 167 obese persons were recruited (45 African Americans, 122 Caribbean Hispanic persons), with a mean age of 14.6+/-2.1 years, a mean body mass index (BMI) of 38+/-7.5 kg/m(2), and mean BMI Z-score of 2.47+/-0.36; 31 nonobese youth were recruited as controls (7 African Americans, 24 Caribbean Hispanic persons), with a mean age of 14.6+/-2.1 years, a mean BMI of 20+/-2.8 kg/m(2), and a mean BMI Z-score of -0.08+/-0.87. The objective was to assess the frequency of elevated blood pressure in obese minority youth. Weight, height, blood pressure (BP), and various biochemical markers were measured in each participant. Overall, 31% of the obese patients had elevated BP, compared with 3% of the control participants. Obese persons with elevated BP had significantly higher BMI, BMI Z-scores, and hemoglobin A1c levels. The frequency of elevated BP and the degree of systolic BP elevation increased with increasing BMI Z-score. Elevated BP was 10 times more frequent in obese minority youth, emphasizing the importance of screening for hypertension in this high-risk population.

Associations among obesity, blood pressure, and left ventricular mass

OBJECTIVES

To measure resting and ambulatory systemic blood pressure (BP) and left ventricular mass (LVM) in prepubertal obese and lean children and to determine their relationships.

STUDY DESIGN

Cross-sectional study including 44 obese and 22 lean prepubertal children (mean age 8.8 +/- 1.5 years). We measured casual and 24-hour ambulatory BP, LVM and LVM index (LVMI) by echocardiography, and whole body lean tissue and fat mass by dual-energy X-ray absorptiometry.

RESULTS

Mean 24-hour systolic BP (124.8 +/- 14.2 vs 105.5 +/- 8.8 mm Hg), diastolic BP (72.8 +/- 7.3 vs 62.7 +/- 3.8 mm Hg), and LVMI (36.1 +/- 5.8 vs 30.9 +/- 5.7, g x m(-2.7)) were significantly higher in obese than in lean subjects. Systolic ambulatory hypertension was present in 47.6% of obese children, and casual BP was normal in 55% of those cases. Body fatness, lean tissue mass, and 24-hour BP correlated positively with LVMI. When adjusted for body fatness, LVMI was only associated with 24-hour systolic BP (adjusted R(2) = 15.9%; P = .001).

CONCLUSIONS

Ambulatory systemic hypertension and increased LVM are found in obese children. Left ventricular mass is partially determined by systemic BP. We conclude that prevention and treatment of childhood obesity should be initiated as early as possible to prevent the premature development of hypertension and end-stage organ damage.

White coat hypertension in childhood: evidence for end-organ effect

OBJECTIVE

To evaluate the hypothesis that white coat hypertension (WCH) represents a prehypertensive state by correlating ambulatory blood pressure monitoring (ABPM) results with BP response to treadmill exercise (TE) and echocardiographic measurement of left ventricular mass index (LVMI) in children with high blood pressure (HBP).

STUDY DESIGN

We evaluated 119 consecutive children age 6 to 18 years (mean = 13.3 years; 65% male) referred for HBP. Office systolic BP (SBP) exceeded the 95th percentile for age/sex/height in all of the children; 10% also had elevated diastolic BP (DBP). WCH was defined as elevated office SBP +/- elevated DBP with normal mean awake ABPM-SBP. ABPM classified 62 subjects as having WCH and 57 as having HBP.

RESULTS

Office BP did not differ between the 2 groups. As defined, awake ABPM-SBP was lower in the WCH group (males: HBP, 142 +/- 12 vs WCH, 124 +/- 5; females: HBP, 137 +/- 8 vs WCH, 121 +/- 5). Awake and asleep DBP and asleep SBP were significantly lower in the WCH group. On TE, maximal SBP exceeded norms for age/sex/body surface area in 63% of the HBP group and 38% of the WCH group. LVMI exceeded the 95th percentile for age/sex in 59% of the males and 90% of the females in the HBP group and in 33% of the males and 36% of the females in the WCH group.

CONCLUSIONS

Exaggerated exercise BP and/or increased LVMI in 62% of those subjects with WCH suggest that this diagnosis in children may represent a prehypertensive state.

Comparison of ambulatory blood pressure and Task Force criteria to identify pediatric hypertension

The aim of this study was to assess the level of agreement between central European ambulatory blood pressure monitoring (ABPM) and American Task Force (TF) criteria when applied to blood pressure (BP) measurements collected by ABPM to evaluate patients with hypertension. In 169 patients, we applied both sets of criteria and calculated mean daytime and nighttime BP and daytime BP loads. The frequency of hypertension for daytime systolic BP was significantly higher when TF criteria were used (p <or= 0.001). However, the frequency of hypertension for nighttime systolic BP was significantly increased when ABPM criteria were applied (p <or= 0.01). Therefore, with daytime ABPM measurements, hypertension was overdiagnosed with TF criteria, while nighttime hypertension was underdiagnosed using TF criteria. In contrast with previous reports, 40% of our patients with essential hypertension showed absence of nighttime dipping, regardless of the criteria used. The number of hypertensive patients was significantly higher using ABPM compared to TF criteria when patients with BP load >or=50% were evaluated (p <or= 0.01). Therefore, current recommendations for ABPM use in children such as to define white coat hypertension or as a screening tool to differentiate between primary and secondary hypertension need to be validated using yet to be produced normative ABPM criteria in American children.

Endothelin-1 gene and endothelial nitric oxide synthase gene polymorphisms in adolescents with juvenile and obesity-associated hypertension

Hypertension is an increasing public health problem all over the world. Essential hypertension accounts for more than 90% of cases of hypertension. It is a complex genetic, environmental and demographic trait. New method in molecular biology has been proposed a number of candidate genes, but the linkage or association with hypertension has been problematic (lack of gene-gene and gene-environment interaction). It is well known that genetic influences are more important in younger hypertensives, because children are relatively free from the common environmental factors contributing to essential hypertension. The association studies compare genotype ferquencies of the candidate gene between patient groups and the controls, in pathways known to be involved in blood pressure regulation. This study examined three polymorphisms of these factors encoding genes (ET-1 G+5665T (Lys198Asn), endothelial nitric oxide synthase (eNOS) T-786C promoter polymorphism and 27-bp repeat polymorphism in intron 4) in adolescents with juvenile essential and obesity-associated hypertension. Significant differences were found in the G/T genotype of the ET-1 polymorphism in the hypertensive and obese+hypertensive patients (body mass index (BMI) > 30). A strong association was detected between the BMI and the polymorphism of the ET-1 gene. It seems that ET-1 gene polymorphism plays a role in the development of juvenile hypertension associated with obesity. Although no significant differences were seen in the case of the eNOS promoter polymorphism and the eNOS 4th intron 27-bp repeat polymorphism. It seems that eNOS may play a role, but this is not the main factor in the control of blood pressure; it is rather a fine regulator in this process. This study with adolescents facilitates an understanding of the genetic factors promoting juvenile hypertension and obesity.

Efficacy and safety of extended release metoprolol succinate in hypertensive children 6 to 16 years of age: a clinical trial experience

OBJECTIVE

To evaluate the efficacy, tolerability, and blood pressure (BP) lowering effect of extended release metoprolol succinate (ER metoprolol) in children 6 to 16 years of age with established hypertension.

STUDY DESIGN

Patients were randomized to one of four treatment arms: placebo or ER metoprolol (0.2 mg/kg, 1.0 mg/kg, or 2.0 mg/kg). Data were analyzed on 140 intent-to-treat patients.

RESULTS

Mean age (+/-SD) was 12.5 +/- 2.8 years and mean baseline BP was 132/78 +/- 9/9 mmHg. Following 4 weeks of treatment, mean changes in sitting BP were: placebo = -1.9/-2.1 mmHg; ER metoprolol 0.2 mg/kg = -5.2/-3.1 mmHg; 1.0 mg/kg = -7.7/-4.9 mmHg; 2.0 mg/kg = -6.3/-7.5 mmHg. Compared with placebo, ER metoprolol significantly reduced systolic blood pressure (SBP) at the 1.0 and 2.0 mg/kg dose (P = .027 and P = .049, respectively), reduced diastolic blood pressure (DBP) at the 2.0 mg/kg dose (P = .017), and showed a statistically significant dose response relationship for the placebo-corrected change in DBP from baseline. There were no serious adverse events or adverse events requiring study drug discontinuation among patients receiving active therapy.

CONCLUSION

These data indicate that ER metoprolol is an effective and well-tolerated treatment for hypertension in children.

Different pathomechanisms of essential and obesity-associated hypertension in adolescents

Obesity-induced hypertension and essential hypertension in lean patients are two different forms of hypertension. The main goal of this study was to test whether there are differences in biochemical parameters between subjects with obesity-associated hypertension and those with essential hypertension. We examined whether the biochemical responses to angiotensin-converting enzyme inhibitor (ACEI) ramipril therapy reveal properties of these two conditions that might explain the differences in clinical outcome. Before ramipril therapy, the hypertensive group exhibited increases in ACE activity (p<0.05), plasma malondialdehyde (MDA) concentration and the malondialdehyde/nitric oxide end-product ratio (MDA/NO(x)) (p<0.05), and decreases in xanthine oxidase (XO) activity (p<0.05) and plasma nitric oxide end-product (NO(x)) level (p<0.01). Before medication, plasma endothelin-1 (ET-1), plasma leptin, and leptin receptor levels were normal. Following ramipril treatment, ACE activity normalized. Before ACE inhibitor treatment, the obese-hypertensive group exhibited elevated levels of plasma ET-1 (p<0.05), plasma leptin (p<0.01), XO activity (p<0.05), plasma MDA and MDA/NO(x) (p<0.05), and reduced levels of plasma NO(x)(p<0.01) and leptin receptors (p<0.001). Following medication, the plasma NO(x) level, MDA/NO(x), and XO activity returned to normal while ACE activity decreased (p<0.001). In patients with essential hypertension, NO availability and ACE activity, and in those with obesity-associated hypertension, hyperleptinemic effects, NO level, endothelin-1 concentration and XO activity, may be important factors in the pathology.

Management of Hypertension in Children and Adolescents With the Metabolic Syndrome

Because elevated blood pressure is one of the defining criteria of the metabolic syndrome, treatment of hypertension will be required in many, if not most, children and adolescents diagnosed with the metabolic syndrome. This review highlights several aspects of the approach to treatment of hypertension in young patients with the metabolic syndrome, including the definition of hypertension, use of nonpharmacologic measures, indications for instituting antihypertensive medications, and the potential adjunctive role that insulin-sensitizing agents may play in blood pressure reduction. The choice of antihypertensive agent is also discussed, along with consideration of the diabetogenic effects of various classes of antihypertensive agents. Consideration of all of these issues is important in achieving blood pressure control in children and adolescents with the metabolic syndrome, as appropriate treatment may help to forestall the development not only of type 2 diabetes but also of the cardiovascular disease that is frequently already present at the time of diagnosis of type 2 diabetes in adults.

Hypertension in children and adolescents

Hypertension is one of the most common health problems in the United States and a powerful independent risk factor for cardiovascular and renal disease. Until recently, the incidence of persistent hypertension in children has been low, with a range of 1% to 3%. Recent data indicate that over the last decade, however, average blood pressure levels have risen substantially among American children. Obesity and other lifestyle factors, such as physical inactivity and increased intake of high-calorie, high-salt foods, are thought to be responsible for this trend. Hypertension in children is currently recognized as an important health issue. There is increasing evidence that hypertension has its antecedents during childhood, because adult blood pressure often correlates with childhood blood pressure. Hypertension in children also is viewed as a significant risk factor for the development of cardiovascular disease in adulthood.

Left ventricular hypertrophy and arterial wall thickening in children with essential hypertension

OBJECTIVE

Our aim was to determine the prevalence of left ventricular hypertrophy (LVH) and increased intima-media thickness (IMT) in Caucasian children with newly diagnosed, untreated essential hypertension (EH).

PARTICIPANTS

Our study cohort consisted of 72 children with EH (mean age: 14.5 years; range: 5-18 years). The control groups consisted of 103 age-matched, healthy children.

METHODS

We evaluated the left ventricular mass (LVM), intima-media thickness in the carotid (cIMT) and superficial femoral (fIMT) arteries, 24-h ambulatory blood pressure, and biochemical cardiovascular risk factors.

RESULTS

Of the hypertensive children examined, 41.6% had LVM above the 95th percentile, and 13.2% had LVM above 51 g/m2.7. Of the hypertensive subjects, the cIMT was above 2 SDS of normal values in 38.8%, and the flMT was above 2 SDS of normal values in 17.5%. Patients with LVM above 51 g/m2.7 had a higher birth weight than other patients. LVM, cIMT, and fIMT correlated with 24-h SBP and pulse pressure; LVM also correlated with homocysteine and serum uric acid concentrations. fIMT correlated with low Aprotein A1 (ApoA1), higher ApoB and C reactive protein, and daily sodium excretion. Step-wise regression analysis revealed that serum uric acid and higher birth weight were predictors for LVM, pulse pressure was a predictor for cIMT, and ApoB was a predictor for fIMT.

CONCLUSIONS

A significant number of adolescents with EH already had cardiovascular damage at diagnosis. LVM and markers of arterial injury correlate with SBP, biochemical, and perinatal cardiovascular risk factors. Serum uric acid and higher birth weight are predictors of LVM.