Neurocognitive Function in Children with Primary Hypertension after Initiation of Antihypertensive Therapy.

OBJECTIVE: To determine the change in neurocognitive test performance in children with primary hypertension after initiation of antihypertensive therapy. STUDY DESIGN: Subjects with hypertension and normotensive control subjects had neurocognitive testing at baseline and again after 1 year, during which time the subjects with hypertension received antihypertensive therapy. Subjects completed tests of general intelligence, attention, memory, executive function, and processing speed, and parents completed rating scales of executive function. RESULTS: Fifty-five subjects with hypertension and 66 normotensive control subjects underwent both baseline and 1-year assessments. Overall, the blood pressure (BP) of subjects with hypertension improved (24-hour systolic BP load: mean baseline vs 1 year, 58% vs 38%, P < .001). Primary multivariable analyses showed that the hypertension group improved in scores of subtests of the Rey Auditory Verbal Learning Test, Grooved Pegboard, and Delis-Kaplan Executive Function System Tower Test (P < .05). However, the control group also improved in the same measures with similar effects sizes. Secondary analyses by effectiveness of antihypertensive therapy showed that subjects with persistent ambulatory hypertension at 1 year (n = 17) did not improve in subtests of Rey Auditory Verbal Learning Test and had limited improvement in Grooved Pegboard. CONCLUSIONS: Overall, children with hypertension did not improve in neurocognitive test performance after 1 year of antihypertensive therapy, beyond that also seen in normotensive controls, suggesting improvements with age or practice effects because of repeated neurocognitive testing. However, the degree to which antihypertensive therapy improves BP may affect its impact upon neurocognitive function.

Ambulatory blood pressure monitoring and neurocognitive function in children with primary hypertension.

BACKGROUND: Children with primary hypertension have been reported to have diminished scores in measures of cognition. However, little is known about the relative correlation between office and ambulatory blood pressure (BP) and neurocognitive test performance, and whether short-term BP variability is associated with decreased neurocognitive function. We sought to determine whether ambulatory BP monitoring (ABPM) was more strongly associated with neurocognitive test performance compared with office BP, and whether increased short-term BP variability was associated with lower neurocognitive scores. METHODS: Seventy-five subjects ages 10-18 years, with untreated primary hypertension, and 75 matched normotensive controls completed neurocognitive testing. All subjects had office BP and ABPM prior to neurocognitive testing. RESULTS: On multivariate analyses, there was no significant association between office BP and neurocognitive tests. However, several ABPM parameters were significantly associated with neurocognitive test scores in the lower quartile, in particular 24 h SBP load and wake systolic blood pressure (SBP) index [Rey Auditory Verbal learning Test (RAVLT) List A Trial 1, 24 h SBP load, odds ratio (OR) = 1.02, wake SBP index, OR = 1.06; List A Total, 24 h SBP load, OR = 1.02, wake SBP index, OR = 1.06; Short Delay Recall, wake SBP index, OR = 1.06; CogState Maze delayed recall, 24 h SBP load, OR = 1.03, wake SBP index, OR = 1.08; Grooved Pegboard, 24 h SBP load, OR = 1.02; all p < 0.05]. In contrast, short-term BP variability measures were not associated with neurocognitive test performance. CONCLUSIONS: ABPM is superior to office BP in distinguishing hypertensive youth with lower neurocognitive test performance.

Neurocognitive Function in Children with Primary Hypertension.

OBJECTIVE: To compare neurocognitive test performance of children with primary hypertension with that of normotensive controls. STUDY DESIGN: Seventy-five children (10-18 years of age) with newly diagnosed, untreated hypertension and 75 frequency-matched normotensive controls had baseline neurocognitive testing as part of a prospective multicenter study of cognition in primary hypertension. Subjects completed tests of general intelligence, attention, memory, executive function, and processing speed. Parents completed rating scales of executive function and the Sleep-Related Breathing Disorder scale of the Pediatric Sleep Questionnaire (PSQ-SRBD). RESULTS: Hypertension and control groups did not differ significantly in age, sex, maternal education, income, race, ethnicity, obesity, anxiety, depression, cholesterol, glucose, insulin, and C-reactive protein. Subjects with hypertension had greater PSQ-SRBD scores (P = .04) and triglycerides (P = .037). Multivariate analyses showed that hypertension was independently associated with worse performance on the Rey Auditory Verbal Learning Test (List A Trial 1, P = .034; List A Total, P = .009; Short delay recall, P = .013), CogState Groton Maze Learning Test delayed recall (P = .002), Grooved Pegboard dominant hand (P = .045), and Wechsler Abbreviated Scales of Intelligence Vocabulary (P = .016). Results indicated a significant interaction between disordered sleep (PSQ-SRBD score) and hypertension on ratings of executive function (P = .04), such that hypertension heightened the association between increased disordered sleep and worse executive function. CONCLUSIONS: Youth with primary hypertension demonstrated significantly lower performance on neurocognitive testing compared with normotensive controls, in particular, on measures of memory, attention, and executive functions.

Aliskiren, the first direct renin inhibitor: assessing a role in pediatric hypertension and kidney diseases.

This article provides a review of the role of aliskiren, a direct renin inhibitor, in pediatric hypertension and kidney diseases. Among the many mechanisms involved in regulating blood pressure, the renin-angiotensin-aldosterone system (RAAS) plays a major role. Additionally, the RAAS has been identified as a contributing factor to cardiovascular and renal diseases for more than three decades. The potential benefits of inhibiting the RAAS by aliskiren alone or in combination with other RAAS blockers (ACEIs, ARBs) seem to be theoretically promising. However, caution should be exercised in treating children, especially in those with significant chronic kidney disease until there is more evidence regarding the safety and efficacy of this new drug in the pediatric population from ongoing clinical trials.

What is the optimal first-line agent in children requiring antihypertensive medication?

There has been an evolution in the understanding of the treatment of hypertension in children and adolescents over the past decade. This has been fueled in part by the increased attention paid to the clinical problem, given the increasing numbers of children and adolescents being diagnosed with this condition. There has also been a growing number of clinical trials performed and completed that demonstrate the blood pressure (BP)-lowering effects of antihypertensives and the side effect profiles of these medications, and that has led to FDA-labeling of many antihypertensive medications for use in children and adolescents. However, none of these trials has provided definitive data on the optimal first line agent for this patient population. Clinical experience and other approaches discussed in this review are still necessary to guide treatment of hypertension in the young. The quest for the optimal antihypertensive agent is just beginning, and it is going to take some extraordinary effort to reach that goal.

Obesity and the role of lifestyle and dietary intervention in the management of pediatric hypertension.

As the prevalence of hypertension in children and adolescents increases within the context of the epidemic of obesity, it is important to recognize that while hypertension may be secondary to an underlying disorder, one must not overlook the impact that overweight and obesity have on the condition. While considering options for the overall management of hypertension in the context of overweight and obesity one should incorporate strategies that focus on therapeutic lifestyle changes, as discussed in the Fourth Report on Blood Pressure in Children and Adolescents. The strategies that will be discussed in this article include weight loss, exercise and dietary interventions. These treatment strategies require a great deal of motivation on the part of the patient, the patient's family and the patient's care providers. Not all strategies will be effective for every individual, but to some extent all patients being treated for hypertension should incorporate elements of therapeutic lifestyle changes into their treatment regimen.

Pharmacokinetics of valsartan in pediatric and adolescent subjects with hypertension.

An open-label, single-dose study is conducted in 26 children with hypertension to characterize the pharmacokinetics of valsartan. Valsartan is administered as an oral suspension (dose of 2 mg/kg), with the maximum single dose being 80 mg. Subjects are stratified into 4 age categories: group 1, 1 to less than 4 years; group 2, 4 to less than 6 years; group 3, 6 to less than 12 years; group 4, 12 to 16 years. Blood samples are collected before and for 24 hours after dosing to quantitate valsartan. Because the body weight of most children in groups 3 and 4 exceeds 40 kg and they received a dose of less than 2 mg/kg, major pharmacokinetic parameters are dose normalized for comparison across the age groups. Dose-normalized maximum plasma concentration and area under the plasma-concentration curve and body weight-normalized apparent oral clearance are comparable for the 4 groups (P > or = .1011). Body weight-normalized apparent oral clearance ranges from 0.061 to 0.089 L/h/kg.

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.

Significance of heritability in primary and secondary pediatric hypertension.

BACKGROUND: Patient weight and family history are significant risk factors for the development of hypertension in children. Multiple genetic factors have been identified in primary (essential) hypertension in adults; however, the delineation of genetic factors in the separate populations of children with primary or secondary hypertension are not well understood. Heritability is the proportion of observed variation in a particular trait that can be attributed to an inherited genetic factor in contrast to environmental factors. In the consideration of hypertension, heritability can be assessed in terms of an underlying continuous gradient of the liability for developing hypertension. With this assumption it is possible to compute heritability using hypertension incidence among relatives and described by Falconer. Heritability values range from 0 (no genetic contribution) to 1 (complete genetic contribution). The aim of this study was to determine the genetic contribution to primary and secondary hypertension in a pediatric population through heritability analysis. METHODS: This was a retrospective case-control analysis of medical records of children (n=276) followed in the Pediatric Nephrology Clinic over a 4-year period from 1999 to 2002. There were 192 children and adolescents with primary hypertension (124 male, 68 female, age 0 to 21 years) and 84 children and adolescents with secondary hypertension (46 male, 38 female, age 0 to 21 years). Each hypertensive group served as the control for the other. Estimates of heritability were made using Falconer's method 2. The model assumes independence between the environment and genetic factors and that the joint distribution of liabilities between parent and child are normally distributed. Problems can arise from computing heritability due to dominance within loci, correlations between nongenetic familial effects, or the presence of a major gene. RESULTS: Of the children and adolescents with primary hypertension, 49% had parents with primary hypertension; and of the children and adolescents with secondary hypertension, 24% had parents with primary hypertension. Of the children and adolescents with primary hypertension, 10% had parents with secondary hypertension; and of the children and adolescents with secondary hypertension, 46% had parents with secondary hypertension. The estimated heritability for primary hypertension was 0.84 (SE=0.21). The estimated heritability for secondary hypertension was 1.14 (SE=0.21). As the value was >1, this indicates that the fit of the liability model is poor and that a few genes, or even one major gene, were significantly involved in the causes of secondary hypertension in the children and adolescents studied. CONCLUSIONS: The results suggest that primary and secondary hypertension do not share the same type of genetic profile. Primary hypertension in children and adolescents is likely due to a large number of additive contributions of genes, although a highly correlated environmental component can not be excluded. The continuous liability model is inappropriate for secondary hypertension because the estimate was substantially greater than one. This study supports the model that secondary hypertension in children and adolescents may be related to just a few genes.

Pharmacologic treatment of chronic pediatric hypertension.

Improved recognition of the relationship between childhood and adult blood pressures and identification of end-organ damage in children, adolescents, and young adults with hypertension has led to increased focus by pediatricians and general practitioners on the detection, evaluation, and treatment of hypertension. Notably, detection, evaluation, and treatment of pediatric hypertension has increased significantly since the first Task Force Report on High Blood Pressure in Children and Adolescents in 1977 with advances in both nonpharmacologic and pharmacologic treatments.Angiotensin-converting enzyme inhibitors (e.g. captopril, enalapril, lisinopril, ramipril) and calcium channel antagonists (e.g. nifedipine, amlodipine, felodipine, isradipine) are the most commonly prescribed antihypertensive medications in children due to their low adverse-effect profiles. Diuretics (e.g. thiazide diuretics, loop diuretics, and potassium-sparing diuretics) are usually reserved as adjunct therapy. Newer agents, such as angiotensin receptor antagonists (e.g. irbesartan), are currently being studied in children and adolescents. These agents may be an option in children with chronic cough secondary to angiotensin-converting enzyme inhibitors. beta-Adrenoreceptor antagonists (e.g. propranolol, atenolol, metoprolol, and labetalol), alpha-adrenoreceptor antagonists, alpha-adrenoreceptor agonists, direct vasodilators, peripheral adrenoreceptor neuron agonists, and combination products are less commonly used in pediatric patients because of adverse events but may be an option in children unresponsive to calcium channel blockers, angiotensin converting-enzyme inhibitors, or angiotensin receptor blockers.

Increased prevalence of elevated blood pressures in HIV-infected children, adolescents and young adults.

BACKGROUND: HIV-infected children and young adults have cardiovascular disease risk factors reflecting chronic infection and the effects of combination antiretroviral (ARV) therapy. We thus sought to characterize the prevalence of and risk factors for high blood pressure (HBP) in this population. METHODS: Retrospective chart review classified subjects aged 2-25 years based on a single clinic blood pressure (BP) reading as normal BP, pre-HBP or HBP. Variables suspected to contribute to elevated BP were compared including body mass index, tobacco use, medical comorbidities, ARV or other medication use, dyslipidemia, ethnicity and family history. RESULTS: In all, 47 of 266 subjects (18%) were found to have HBP. Among children and adolescents aged 2-17 years, 21 of 107 (20%) had HBP. Comorbidities believed to elevate BP, such as polycystic ovarian syndrome, obstructive sleep apnea or cocaine exposure, were significant risk factors for elevated BP, with 35% of subjects with these comorbidities having HBP, compared with 16% of subjects without (P = 0.01). Male gender and tobacco use were also risk factors associated with elevated BPs. HBP was more common in overweight subjects (26%) than not overweight (15%) but did not reach statistical significance (P = 0.15). ARV medication use and higher HIV-1 RNA were not associated with HBP. CONCLUSIONS: Our finding of 20% prevalence of HBP in a cohort of HIV-infected children represents a potentially alarming figure. The explanation for this finding is unclear, but even if it is because of comorbid conditions, the life-long cardiovascular risks associated with HIV infection and its management mandate the need for closer monitoring and possibly treatment of elevated BP in this population.

Sleep disordered breathing as measured by SRBD-PSQ and neurocognition in children with hypertension.

BACKGROUND: Cognitive test performance is decreased in hypertensive adults and children, a finding postulated to represent early target-organ damage to the brain. Hypertensive children are often obese, a comorbidity associated with sleep disordered breathing (SDB), itself associated with cognitive problems; potentially confounding the relation between hypertension (HTN) and neurocognition. Our objective was to determine the association between SDB as measured by a scale and questionnaire score and neurocognition among participants enrolled in an ongoing multicenter study of cognition in children with HTN. METHODS: Subjects completed laboratory-based neurocognitive tests. Parents and subjects completed rating scales of executive function, mood, and behavior problems. Parents completed the Sleep-Related Breathing Disorder scale of the Pediatric Sleep Questionnaire (SRBD-PSQ). RESULTS: To date, 38 HTN subjects and 34 control subjects have completed neurocognitive testing and the SRBD-PSQ. Median SRBD-PSQ scores were similar between groups but the HTN group had a higher percentage of subjects with SRBD-PSQ scores in the range suggestive of obstructive sleep apnea (26% vs. 6%, P = 0.03). Overall, higher SRBD-PSQ scores were not significantly associated with worse performance on laboratory-based measures of executive function and other cognitive domains but were significantly associated with worse scores on rating scales of executive function as well as mood and behavior problems. CONCLUSIONS: A larger proportion of children with HTN had scores suggestive of SDB. The results underscore the importance of using a multi-method approach in the assessment of cognition and adjusting for potential confounding effects of SDB in studies of cognition in hypertensive children.

Management of nephrotic syndrome in children.

Idiopathic childhood nephrotic syndrome generally has a favorable long-term prognosis. Prompt administration of and improved guidelines for monitoring therapy have decreased morbidity and mortality. The treatment goal is to induce prompt remission while minimizing complications and adverse events. Aggressive therapy induces remission and decreases the frequency of relapse in most patient populations; however, such treatment often results in unnecessary toxicity. We critically assessed the current clinical evidence that supports each pharmacologic therapy. For each drug regimen, the risks and monitoring parameters required to reduce complications and optimize therapy are discussed. Some of the treatments are the common corticosteroid approaches, cytotoxic therapies (chlorambucil, cyclophosphamide), cyclosporine, less frequently used drugs (e.g., levamisole), and experimental therapies. Further studies are needed to identify the most effective and least toxic therapeutic regimens for inducing and maintaining remission in children with nephrotic syndrome.

Effectiveness of pretreatment in decreasing adverse events associated with pamidronate in children and adolescents.

STUDY OBJECTIVES: To assess the effectiveness of pretreatment with ibuprofen or acetaminophen compared with no pretreatment in decreasing adverse events in children and adolescents receiving the first and second series of pamidronate therapy; and to compare the effectiveness of ibuprofen versus acetaminophen for prevention of adverse events associated with pamidronate infusion. DESIGN: Retrospective case review. SETTING: Children's hospital. PATIENTS: Twenty-seven children and adolescents aged 3-21 years receiving pamidronate therapy. MEASUREMENTS AND MAIN RESULTS: Data for patient demographics, medical history, genetic history of disease, pamidronate infusion dosage, and concurrent drug therapy were collected. Adverse drug events secondary to pamidronate infusion and subsequent drug therapies received were documented. Data were categorized by presence or absence of pretreatment and analyzed by cross-tabulation to determine whether the presence of adverse events differed between groups (no pretreatment, acetaminophen pretreatment, and ibuprofen pretreatment). Fewer adverse events were reported in patients receiving ibuprofen (17% of patients) versus acetaminophen (83%). Differences in presence of fever (chi2 = 10.5, p = 0.005) and bone pain (chi2 = 7.3, p = 0.027) among the three pretreatment groups were also statistically significant. CONCLUSION: Pretreatment with ibuprofen or acetaminophen appears to decrease the occurrence of adverse events from pamidronate therapy. However, adverse events seem less likely to occur with ibuprofen. Further study is necessary to determine the relationship between occurrence of adverse events, other possible treatment strategies, and patient adherence with pamidronate therapy.

Neonatal hypertension.

The incidence of neonatal hypertension (HTN) remains low, at less than 2%, and its etiology is varied. Strict definitions of HTN in neonates are unavailable, and the decision to treat is based on opinion rather than evidence. More studies are needed to define normal blood pressure in neonates and to refine current reference values, thus permitting a better definition of HTN. Most causes of neonatal HTN, the most common of which seems to be renovascular disease, are determined by history and basic clinical investigations. Treatment is guided by clinical judgment and expert opinion, given the limited number of clinical trials.