National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents. The fourth report on the diagnosis, evaluation, and treatment of high blood pressure in children and adolescents. Pediatrics. 2004;114:555-576. [PMID: 15286277 DOI: 10.1542/peds.114.2.s2.555]

Complications and comorbidities of type 2 diabetes

A number of children and adolescents are at risk for complications and comorbidities of type 2 diabetes, prediabetes, or metabolic syndrome. These complications and comorbidities are likely to present significant personal burdens and societal costs. The pediatrician should be aware of screening and interventions to lessen the effect of these risks on their patients. Societal-wide lifestyle changes are needed desperately to reduce the prevalence of these largely preventable diseases.

Steroid 11-Beta-Hydroxylase Deficiency Caused by Compound Heterozygosity for a Novel Mutation, p.G314R, in One CYP11B1 Allele, and a Chimeric CYP11B2/CYP11B1 in the Other Allele

AIMS

Steroid 11beta-hydroxylase deficiency (11beta-OHD) is the second most common (5-8%) cause of congenital adrenal hyperplasia (CAH), and results from homozygous or compound heterozygous mutations or deletions of the responsible gene CYP11B1. In order to better understand the molecular basis causing 11beta-OHD, we performed detailed studies of CYP11B1 in a newly described patient diagnosed with the classical signs of 11beta-OHD.

METHODS

CYP11B1 of the patient was investigated by polymerase chain reaction (PCR), sequencing, restriction fragment length polymorphism (RFLP) analysis, Southern blotting, and transient cell expression.

RESULTS

We identified two new mutated alleles in CYP11B1. In one allele CYP11B1 has a g.940G-->C (p.G314R) missense mutation. On the other allele we found a chimeric gene that consists of part of the aldosterone synthase gene (CYP11B2) at exons 1-3 and part of the 11beta-hydroxylase gene (CYP11B1) at exons 4-9. Inin vitro studies, the g.940G-->C (p.G314R) mutation abolished all hydroxylase activity in comparison with the wild-type 11beta-hydroxylase. The chimeric CYP11B2/CYP11B1 protein retained 11beta-hydroxylase enzymatic activity in vitro.

CONCLUSION

This case is caused by compound heterozygosity for a nonfunctional missense mutation and a chimeric CYP11B2/CYP11B1 gene with hydroxylase activity that is controlled by the CYP11B2 promoter. The most likely explanation is that the CYP11B2 promoter does not function in the zona fasciculata/reticularis where cortisol is exclusively synthesized.

Effect of obesity and high blood pressure on plasma lipid levels in children and adolescents

OBJECTIVE

To examine the extent of blood lipid abnormalities in overweight children and to determine whether the prevalence of dyslipidemia is different in overweight children with elevated blood pressure (BP) compared with overweight children with normal BP (NBP).

METHODS

A retrospective, case-control study on 497 patients 2 to 18 years of age at the Nemours Weight Management Clinic of duPont Hospital for Children was conducted to compare the prevalence of abnormal plasma lipid levels in overweight children with high BP with overweight children with NBP.

RESULTS

Elevated BP was detected in 34.7% of the sample; 27.9% had prehypertension (pre-HTN), and 6.8% had HTN. The rates of abnormal plasma lipid levels were high among overweight children with both NBP and HTN. Significantly more boys with high BP had low high-density lipoprotein cholesterol compared with boys with NBP (49.4% vs 27.6%). Significantly more severely obese boys had low high-density lipoprotein cholesterol compared with moderately obese boys (40.3% vs 29.3%). The prevalence of elevated BP was much greater in severely obese boys and girls (46.5% and 39%) than moderately obese boys and girls (28.1% and 23.1%).

CONCLUSIONS

The high prevalence of dyslipidemia found in this overweight sample supports recent recommendations to collect plasma lipid levels in not only overweight children with BP > or =90th percentile but also in all overweight children.

MRI detection of atrophic kidney in a hypertensive child with a single kidney

The role of magnetic resonance imaging (MRI) in the work-up of secondary causes of pediatric hypertension is typically restricted to that of renovascular causes where main renal artery stenosis is suspected. We report a case of a 10-year-old female child with hypertension, who was thought to have unilateral renal agenesis, because only a solitary left kidney could be visualized on both ultrasound and renal scintigraphy. Our patient underwent magnetic resonance imaging because of suspected renal artery stenosis in her solitary left kidney. At MRI she was found to have a normal left kidney. However, a very tiny, atrophic right kidney was also visualized. A laparoscopic right nephrectomy was performed, which resulted in complete resolution of her hypertension. This case illustrates a possible additional role for MRI in a very small subset of pediatric hypertensive patients: those with a single kidney on ultrasound.

Childhood obesity and type 2 diabetes mellitus

Until recently, the majority of cases of diabetes mellitus among children and adolescents were immune-mediated type 1a diabetes. Obesity has led to a dramatic increase in the incidence of type 2 diabetes (T2DM) among children and adolescents over the past 2 decades. Obesity is strongly associated with insulin resistance, which, when coupled with relative insulin deficiency, leads to the development of overt T2DM. Children and adolescents with T2DM may experience the microvascular and macrovascular complications of this disease at younger ages than individuals who develop diabetes in adulthood, including atherosclerotic cardiovascular disease, stroke, myocardial infarction, and sudden death; renal insufficiency and chronic renal failure; limb-threatening neuropathy and vasculopathy; and retinopathy leading to blindness. Health care professionals are advised to perform the appropriate screening in children at risk for T2DM, diagnose the condition as early as possible, and provide rigorous management of the disease.

White-coat and masked hypertension in children: association with target-organ damage

White-coat hypertension (WCH) and masked hypertension have been associated with increased cardiovascular risk in adults. In the current study, we investigated: (a) the prevalence of WCH and masked hypertension in pediatric patients and (b) the association of these conditions with target organ damage. A total of 85 children underwent office blood pressure measurements, 24-h ambulatory blood pressure monitoring, echocardiography and ultrasonography of the carotid arteries. Subjects with both office and ambulatory normotension or hypertension were characterized as confirmed normotensives or hypertensives, respectively; WCH was defined as office hypertension with ambulatory normotension and masked hypertension as office normotension and ambulatory hypertension. WCH was found in 12.9% and masked hypertension in 9.4% of the subjects. WCH was significantly more prevalent in obese subjects, while masked hypertension was only present in non-obese ones. Confirmed and masked hypertensives had significantly higher left ventricular mass index than confirmed normotensives (34.0+/-5.8 g/m(2.7), 31.9+/-2.9 g/m(2.7) and 25.3+/-5.6 g/m(2.7), respectively, P<0.05). White-coat hypertensives tended to have higher left ventricular mass index than confirmed normotensives, but the difference was not statistically significant (27.8+/-5.1 g/m(2.7) versus 25.3+/-5.6 g/m(2.7)). No significant differences were found in the intima-media thickness of the carotid arteries between confirmed normotensives, white-coat hypertensives, masked hypertensives and confirmed hypertensives. WCH and masked hypertension are common conditions in children. Confirmed and masked hypertension in pediatric patients are accompanied by increased left ventricular mass index.

Atherosclerosis in childhood and adolescent type 1 diabetes: early disease, early treatment?

Autopsy studies have shown that atherosclerosis begins in adolescence in otherwise healthy individuals, and imaging techniques have shown that atherosclerosis develops earlier and is more prevalent in children with diabetes than in age-matched healthy controls. Cardiovascular disease has now overtaken diabetic nephropathy as the leading cause of premature mortality in young adults with diabetes, and the emphasis on disease prevention has accordingly shifted to a younger age group. The majority of children and adolescents with diabetes have suboptimal blood glucose control, and this contributes to accelerated arterial disease in this age group. Other conventional risk factors for coronary heart disease also need to be considered and treated aggressively. Effective early prevention of cardiovascular disease will involve lifestyle modification and full implementation of existing treatment guidelines, and large-scale prospective studies will be needed to establish the risks and benefits of early pharmacological intervention in children and adolescents.

Twenty-four-hour ambulatory blood pressure monitoring in infants and toddlers

During the past several years, 24-hour (24-h) ambulatory blood pressure monitoring (ABPM) has become a useful tool for the diagnosis and management of children and adolescents with elevated blood pressure (BP). Some reports have also provided blood pressure nomograms for particular devices. However, there are very few reports of the use of this method in very young children. In our study we investigated the applicability of ABPM in 97 healthy infants and toddlers, aged from 2 to 30 months. A satisfactory ABPM profile was obtained in 86.6% of the children, with an average of 75.0% satisfactory BP recordings. The mean +/- SD systolic and diastolic BP of healthy infants and toddlers was 99+/-12/62+/-12 mmHg during the daytime and 95+/-11/57+/-10 mmHg during the night, with no gender difference being observed. The 24-h mean +/- SD systolic and diastolic BP, which may be a more appropriate measure of BP in this particular age group, was found to be 97+/-12/59+/-11 mmHg. We also confirmed the increase in systolic and diastolic BP with increased height (length). There was only a slight nocturnal decrease in BP. We conclude that this method is applicable for the assessment of blood pressure in very young children.

How are hypertensive children evaluated and managed? A survey of North American pediatric nephrologists

To assess how children with hypertension are currently evaluated and managed, we surveyed 438 North American pediatric nephrologists on how they measure blood pressure (BP), BP goals used in pharmacologically treated patients, and antihypertensive drug choices. 190 replies were received (43% response rate), and 185 were analyzable. Oscillometric and aneroid sphygmomanometers were the most commonly used devices for office BP measurement (74.8% of respondents). Ambulatory blood pressure monitoring was used by 63% of respondents. Goal BP in pharmacologically treated patients was set at the 95th percentile by 39% of respondents, and at the 90th percentile by 59%. Only 37% used a different goal BP in children with hypertension and renal disease; of these, 85% used a lower goal and 15% a higher goal. For hypertensive children with diabetes, 47% used a different goal; 99% lower and 1% higher. Whereas angiotensin-converting enzyme inhibitors (ACEI) and calcium-channel blockers (CCB) were chosen by similar proportions of respondents as initial agents for treatment of primary hypertension, most (84%) chose ACEI as their initial agent for hypertension in children with renal disease. Although most pediatric nephrologists treat hypertensive children to a BP goal below the 90th percentile, most do not use lower goals for patients with renal disease or diabetes, in contrast with current recommendations for treatment of adults with these conditions. These findings highlight the need for further studies to determine whether recommendations for treatment of hypertension in adults should be followed in children.

Pulse transit time as a derived noninvasive mean to monitor arterial distensibility changes in children

Changes in arterial distensibility have been widely used to identify the presence of cardiovascular abnormalities like hypertension. Pulse wave velocity (PWV) has shown to be related to arterial distensibility. However, the lack of suitable techniques to measure PWV nonintrusively has impeded its clinical usefulness. Pulse transit time (PTT) is a noninvasive technique derived from the principle of PWV. PTT has shown its capabilities in cardiovascular and cardiorespiratory studies in adults. However, no known study has been conducted to understand the suitability and utility of PTT to estimate PWV in children. Two computational methods to derive PWV from PTT values obtained from 23 normotensive Caucasian children (19 males, aged 5-12 years old) from their finger and toe were conducted. Furthermore, the effects of adopting different postures on the PWV derivations were investigated. Statistical analyses were performed in comparison with two previous PWV studies conducted on children. Results revealed that PWV derived from the upper limb correlated significantly (P<0.05) regardless of computing methods or postures adopted. The findings here suggest that PTT measurement can be used as a convenient and noninvasive surrogate measure of derived PWV in prolonged clinical studies, especially on younger or less cooperative children. Furthermore, the simple set-up and noninvasive nature of PTT can promote its usefulness in ambulatory monitoring.

Associations between adiposity, family history of CHD and blood pressure in 3–8 year-old children

The purpose of this study was to examine the relationships between overall and central adiposity, a family history of coronary heart disease (FHCHD), and blood pressure (BP) in young children. We were specifically interested in determining whether the relationship between adiposity and BP was modified by a FHCHD. Subjects were 130 (68 males, 62 females) young children (mean age 6.0 years). Indicators of adiposity included the body mass index, waist circumference, skinfold thickness, and body composition determined by dual energy X-ray absorbtiometry (DXA). BP was measured by standard procedures. FHCHD was reported by the parent on a questionnaire. Approximately 19% of the total sample was classified as overweight and almost 50% were classified as prehypertensive (22.4%) or hypertensive (24.8%). In the total sample, 21 of 27 correlations were significant and ranged from 0.03 to 0.52. Correlations for systolic blood pressure appeared to be stronger in female subjects. Most of the correlations for diastolic blood pressure and mean arterial pressure were significant in both sexes and, in general, ranged between 0.30 and 0.50. Overweight status was significantly associated with high BP (crude odds ratio=3.65, 95% confidence intervals 1.40-9.49). There were no significant associations between a positive FHCHD and BP, and the correlations between BMI, WC, and BP were similar in magnitude in subjects with and without a FHCHD. In conclusion, both overall and central adiposity are important determinants of resting BP in young children. A FHCHD was not associated with BP and nor were the associations between adiposity and BP modified by a FHCHD.

A diagnostic approach for the child with hypertension

Hypertension during childhood is not rare, with an estimated prevalence of between 1% and 2%, although it is often an underrecognized clinical entity. Elevated blood pressure may be a sign of underlying disease or it may represent early onset of essential hypertension. In recent years the measurement of blood pressure has been emphasized as an important component of the routine pediatric physical examination that enables early detection of children with hypertension. In the evaluation of the child with documented blood pressure elevation, confirmation of truly and persistently elevated blood pressure is of the utmost importance. In addition, a thorough history and a full clinical examination are essential. These are followed by appropriate investigations, which are tailored to the age of the child and to the severity of the blood pressure elevation. Investigations should not only focus on a search for the underlying cause, but also on establishing effects on target organs, complications or additional diseases and on assessment of the total cardiovascular risk to the individual patient. An algorithm, which is a valuable diagnostic tool for the diagnosis and management of the child with hypertension, is presented. All children with confirmed hypertension need long-term follow-up, counseling and treatment. In those cases where an underlying cause of the hypertension is detected, the established diagnosis then determines the specific therapy and management.

Pediatric aspects of diabetic kidney disease

Type 1 diabetes mellitus (DM1) commonly occurs in childhood, although many pediatric centers are now seeing more cases of type 2 diabetes (DM2). Kidney failure caused by either type of diabetes is uncommon during childhood, but these years of hyperglycemia contribute to long-term complications. All children with diabetes warrant screening of glomerular filtration rate, blood pressure, and urine albumin excretion. Screening should begin after 5 years of DM1 or at puberty. A similar screening strategy should start at the time of diagnosis of DM2. Atypical features such as dipstick positive proteinuria or active urine sediment may warrant referral to a nephrologist for evaluation, including biopsy. The first line of treatment in either form of diabetes is achieving the best glycemic control possible. Patients developing microalbuminuria or hypertension should receive antiangiotensin II drugs. Adult studies suggest blood pressure goals should be lower in diabetes than in the general population. Although direct evidence is not yet available in children, achieving blood pressure below the 90th percentile for age, height, and gender seems prudent. Longitudinal studies and new screening tests may allow detection of susceptible children earlier in the course of DM1 or DM2, perhaps allowing prevention of diabetic kidney disease.

Advances in the pathogenesis and management of hypertensive crisis

PURPOSE OF REVIEW

This review summarizes recent insights into to the pathophysiology of hypertensive crisis with the emphasis on newly discovered molecular mechanisms underlying hypertension and also updates current therapeutic options for treating hypertensive crisis in children.

RECENT FINDINGS

There is growing evidence that the renin-angiotensin system plays a key role in the pathogenesis of hypertensive crises. Recent studies have shown that oxidative stress and factors affecting endothelial function are also important. Treatment of hypertensive crisis still focuses on lowering of blood pressure in an expeditious but safe manner. There is growing experience with IV nicardipine, which is becoming a viable alternative to sodium nitroprusside in children.

SUMMARY

Current knowledge of hypertensive crisis emphasizes the need for additional animal and translational studies with the goal of identifying the underlying molecular pathogenesis and developing new therapies to optimize future treatment of hypertensive emergencies.

Children in South Asia Have Higher Body Mass–Adjusted Blood Pressure Levels Than White Children in the United States

BACKGROUND

Blood pressure during childhood is an established predictor of adult blood pressure, which in turn increases mortality as a result of cardiovascular disease. Adult South Asian populations are particularly predisposed to cardiovascular disease compared with whites, but the prevalence of high blood pressure and determinants of blood pressure in South Asian children have not been explored or compared with those of white children.

METHODS AND RESULTS

Analyses were performed on 5641 South Asian children 5 to 14 years old included in the nationally representative National Health Survey of Pakistan (NHSP) (1990-1994) and on 4756 white children 5 to 14 years old included in Third National Health and Nutrition Examination Survey (NHANES III) (1988-1994). Anthropometric measurements were obtained. Blood pressure was measured twice in the seated position with a mercury sphygmomanometer and an appropriate-size cuff. High blood pressure was defined as a systolic or diastolic blood pressure level that was > or =95th percentile of age-, sex-, and height-percentile-specific reference level for the US population. Mean body mass index (BMI)-adjusted blood pressure values were compared among children in 2 data sets by use of linear regression analysis. The overall prevalence (95% CI) of high blood pressure in South Asian children 5 to 14 years old was 12.2% (11.3% to 13.1%): 15.8% (14.5% to 17.1%) in boys and 8.7% (7.6% to 9.8%) in girls. This is in sharp contrast with the predicted 5% prevalence of high blood pressure in children in the United States (P<0.001). The mean BMI-adjusted systolic blood pressure levels (SD) were 100 (11) versus 99 (11) mm Hg (P<0.001), and diastolic blood pressure levels (SD) were 63 (10) versus 52 (12) mm Hg (P<0.001) in NHSP versus NHANES III, respectively.

CONCLUSIONS

South Asian children have higher body-mass-adjusted blood pressure levels than white children in the United States. Further studies are needed to determine factors responsible for these differences. Immediate attention is needed to address high blood pressure and its risk factors in native South Asian children.

Prevalence, persistence, and clinical significance of masked hypertension in youth

Masked hypertension, an elevated daytime ambulatory blood pressure in the presence of a normal office blood pressure, confers an increased cardiovascular risk to adults. We investigated the prevalence, persistence, and clinical significance of masked hypertension in children and adolescents. We enrolled 592 youths (6 to 18 years old). Youths with masked hypertension (n=34) and a random sample of the normotensive participants (n=200) were followed-up. In a nested case-control study, we compared echocardiographic left ventricular mass among cases with persistent masked hypertension and normotensive controls. At baseline, mean age was 10.2 years; 535 youths were normotensive on office and daytime ambulatory blood pressure measurement (90.4%), and 45 had masked hypertension (7.6%). Compared with normotensive controls, participants with masked hypertension had a higher ambulatory pulse rate, were more obese, and were 2.5-times more likely to have a parental history of hypertension. Among 34 patients with masked hypertension (median follow-up 37 months), 18 became normotensive, 13 had persistent masked hypertension, and 3 had sustained hypertension. Patients with persistent masked hypertension (n=17) or who progressed from masked to sustained hypertension (n=3) had a higher left ventricular mass index (34.9 versus 29.6 g/m2.7; P=0.023) and a higher percentage with left ventricular mass index above the 95th percentile (30% versus 0%; P=0.014) than normotensive controls. In children and adolescents, masked hypertension is a precursor of sustained hypertension and left ventricular hypertrophy. This condition warrants follow-up and, once it becomes persistent, is an indication for blood pressure-lowering treatment.

Predictive regression equations and clinical uses of peripheral pulse timing characteristics in children

Studies have shown that increased arterial stiffening can be an indication of cardiovascular diseases like hypertension. In clinical practice, this can be detected by measuring the blood pressure (BP) using a sphygmomanometer but it cannot be used for prolonged monitoring. It has been established that pulse wave velocity (PWV) is a direct measure of arterial stiffening but its usefulness is hampered by the absence of non-invasive techniques to estimate it. Pulse transit time (PTT) is a simple and non-invasive method derived from PWV. However, limited knowledge of PTT in children is found in the present literature. The aims of this study are to identify independent variables that confound PTT measure and describe PTT regression equations for healthy children. Therefore, PTT reference values are formulated for future pathological studies. Fifty-five Caucasian children (39 male) aged 8.4 +/- 2.3 yr (range 5-12 yr) were recruited. Predictive equations for PTT were obtained by multiple regressions with age, vascular path length, BP indexes and heart rate. These derived equations were compared in their PWV equivalent against two previously reported equations and significant agreement was obtained (p < 0.05). Findings herein also suggested that PTT can be useful as a continuous surrogate BP monitor in children.

Cardiovascular disorders in the college student

This article provides an overview of diagnosis and treatment of college students with possible congenital or acquired heart problem issues. Preventive cardiac concerns and issues regarding risk factors for atherosclerotic heart disease are discussed. College students with corrected or palliated heart conditions are included because they are an expanding segment of the adult cardiac population. Selected major syndromes with associated cardiac anomalies and complications are included. Finally, reinforcement and review of cardiac diagnosis or management issues occurring in college students (six case scenarios) are included in the appendix.

Measuring blood pressure using the mercury sphygmomanometer

Automated blood pressure devices have been embraced by clinicians for their convenience and ease of use. However, the pressure to remove mercury-containing medical devices is leading to the demise of the mercury sphygmomanometer and the loss of manual blood pressure measurement skills. The article argues that there is still a place for the mercury sphygmomanometer, particularly when a clinical decision is based on the blood pressure readings. It presents a review of the available literature to explain the rationale for the use of manual sphygmomanometry and gives a step-by-step guide to the procedure with current supporting evidence. There is a brief discussion of special considerations when dealing with certain client groups. Normal blood pressure ranges for adults and children have been included along with a definition of hypertension for both groups.

Intestinal fatty acid binding protein and microsomal triglyceride transfer protein polymorphisms in French-Canadian youth

Growing evidence suggests an association between lipid abnormalities and fatty acid binding protein (FABP) and microsomal triglyceride transfer protein (MTP) gene variants. Our objectives were to determine whether Ala54Thr FABP2 and G-493T MTP polymorphisms are associated with increased risks of insulin resistance syndrome (IRS) in youth and/or modify the expression of accompanying dyslipidemia. Our study of 1,742 French-Canadians aged 9, 13, and 16 years did not provide evidence of a potential predisposition to IRS related to either FABP2 or MTP genotypes. However, we observed a heterogeneity of the FABP2 effect by IRS status on total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), and apolipoprotein B (apoB) concentrations (P for interaction=0.045, 0.018, and 0.017, respectively). Among the metabolic components of IRS, only triglyceride (TG) displayed an interaction with FABP2 polymorphism: compared with Thr/Ala and Ala/Ala, the Thr/Thr genotype was associated with a steeper increase in TC, LDL-C, and apoB parallel to TG concentrations (P <0.001). IRS did not modify the associations between the MTP polymorphism and any of the biochemical parameters. Our study suggests that the effects of FABP2 allelic variations on lipid traits are context dependent, indicating that this variant may play an important role in cardiovascular pathogenesis in the presence of IRS or hypertriglyceridemia.