Strict blood-pressure control and progression of renal failure in children

Reliability of resting blood pressure measurement and classification using an oscillometric device in children with chronic kidney disease

OBJECTIVE

To compare the reliability of blood pressure (BP) readings obtained with an oscillometric device with those obtained by auscultation and assess for differences in BP status classification based on the 2 techniques.

STUDY DESIGN

Resting BP was measured by auscultation and with an oscillometric device at the same encounter in 235 subjects enrolled in the Chronic Kidney Disease in Children study. Resting auscultatory BP values were averaged and compared with averaged oscillometric readings. BP agreement by the 2 methods was assessed using Bland-Altman plots, and BP status classification agreement was assessed by calculation of kappa statistics.

RESULTS

Oscillometric BP readings were higher than auscultatory readings, with a median paired difference of 9 mm Hg for systolic BP (SBP) and 6 mm Hg for diastolic BP (DBP). Correlation for mean SBP was 0.624 and for mean DBP was 0.491. The bias for oscillometric BP measurement was 8.7 mm Hg for SBP (P < .01) and 5.7 mm Hg for DBP (P < .01). BP status classification agreement was 61% for SBP and 63% for DBP, with Kappa values of .31 for SBP and .20 for DBP.

CONCLUSIONS

Compared with auscultation, the oscillometric device significantly overestimated both SBP and DBP, leading to frequent misclassification of BP status.

Causes and outcome of late referral of children who develop end-stage kidney disease

AIMS

This study aims to characterise the timing of referral to a paediatric nephrology unit of children who develop end-stage kidney disease (ESKD). This study also aims to determine whether late referral (LR) influences outcomes and to explore factors that may lead to LR.

METHODS

A retrospective case review of all incident patients with ESKD who received renal replacement therapy (RRT) at a single paediatric centre. Time between referral to a paediatric nephrologist and commencement of RRT, demographic and clinical data were collated. Estimated glomerular filtration rate (eGFR) at referral was calculated using height and creatinine. LR was defined as having an eGFR ≤ 30 mL/min/1.73 m(2) when first seen by a paediatric nephrologist.

RESULTS

RRT was initiated for 74 patients < 18 years of age between 1988 and 2010. The median age at referral was 2.0 years (birth-15.9 years) and age at RRT was 10.0 years (6 days-17.4 years). Children referred before age 1 year (41%) had a more prolonged course before ESKD. Median (interquartile range) eGFR at referral of children > 1 year was 27.2 (9.0-52.0) mL/min/1.73 m(2) . Twenty-two (55%) of these children were referred late (LR) with an eGFR ≤ 30 mL/min/1.73 m(2) . LR patients were more likely to have glomerulonephritis or haemolytic uraemic syndrome and to live in a remote or outer regional area. LR patients had higher urea, lower haemoglobin and were more likely to receive haemodialysis via a vascular catheter.

CONCLUSIONS

A significant proportion of children who develop ESKD are referred late to nephrology units with potentially preventable complications. Aetiology of renal disease and geographic isolation contribute to LR.

Epidemiology of chronic kidney disease in children

In the past 30 years there have been major improvements in the care of children with chronic kidney disease (CKD). However, most of the available epidemiological data stem from end-stage renal disease (ESRD) registries and information on the earlier stages of pediatric CKD is still limited. The median reported incidence of renal replacement therapy (RRT) in children aged 0-19 years across the world in 2008 was 9 (range: 4-18) [corrected] per million of the age-related population). [corrected] The prevalence of RRT in 2008 ranged from 18 to 100 per million of the age-related population. Congenital disorders, including congenital anomalies of the kidney and urinary tract (CAKUT) and hereditary nephropathies, are responsible for about two thirds of all cases of CKD in developed countries, while acquired causes predominate in developing countries. Children with congenital disorders experience a slower progression of CKD than those with glomerulonephritis, resulting in a lower proportion of CAKUT in the ESRD population compared with less advanced stages of CKD. Most children with ESRD start on dialysis and then receive a transplant. While the survival rate of children with ERSD has improved, it remains about 30 times lower than that of healthy peers. Children now mainly die of cardiovascular causes and infection rather than from renal failure.

Uric acid level and elevated blood pressure in US adolescents: National Health and Nutrition Examination Survey, 1999-2006

Uric acid is associated with cardiovascular disease and cardiovascular disease risk factors in adults, including chronic kidney disease, coronary artery disease, stroke, diabetes mellitus, preeclampsia, and hypertension. We examined the association between uric acid and elevated blood pressure in a large, nationally representative cohort of US adolescents, a population with a relatively low prevalence of cardiovascular disease and cardiovascular disease risk factors. Among 6036 adolescents 12 to 17 years of age examined in the 1999-2006 National Health and Nutrition Examination Survey, the mean age was 14.5 years, 17% were obese (body mass index: ≥95th percentile), and 3.3% had elevated blood pressure. Mean serum uric acid level was 5.0 mg/dL, and 34% had a uric acid level ≥5.5 mg/dL. In analyses adjusted for age, sex, race/ethnicity, and body mass index percentile, the odds ratio of elevated blood pressure, defined as a systolic or diastolic blood pressure ≥95th percentile for age, sex, and height, for each 0.1-mg/dL increase in uric acid level was 1.38 (95% CI: 1.16-1.65). Compared with <5.5 mg/dL, participants with a uric acid level ≥5.5 mg/dL had a 2.03 times higher odds of having elevated blood pressure (95% CI: 1.38-3.00). In conclusion, increasing levels of serum uric acid are associated with elevated blood pressure in healthy US adolescents. Additional prospective studies and clinical trials are needed to determine whether uric acid is merely a marker in a complex metabolic pathway or causal of hypertension and, thus, a potential screening and therapeutic target.

Systemic arterial hypertension in children following renal transplantation: prevalence and risk factors

BACKGROUND

Control of blood pressure (BP) following renal transplantation may improve allograft and patient survival. Our aims were (i) to describe the distribution of BP and the prevalence of systolic and/or diastolic hypertension in children over the first 5 years following renal transplantation and (ii) to evaluate clinical risk factors and centre-specific factors associated with hypertension in this population.

METHODS

We conducted a retrospective case note review of all current paediatric kidney transplant patients in the UK, with data collected at 6 months, 1, 2 and 5 years following transplantation in subjects with hypertension (systolic and/or diastolic BP > 95th > ) and non-hypertensive subjects BP ≤ 95th > .

RESULTS

In total, 27.3% (117/428), 27.6% (118/428), 26.0% (95/365) and 25.6% (50/195) of the patients were hypertensive (systolic and/or diastolic BP > 95th > ) at 6 months, 1, 2 and 5 years following transplantation, respectively. A total of 58.4% of the patients at 6 months, 52.8% at 1 year, 48.2% at 2 years and 48.2% at 5 years were receiving anti-hypertensive therapy, of whom 31.6-36.6% remained hypertensive. When subjects were identified as being hypertensive, on anti-hypertensive medication or had untreated hypertension (systolic and/or diastolic BP > 95th > ), 66.4, 61.0, 56.4 and 55.9% of patients were hypertensive at 6 months, 1, 2 and 5 years, respectively. In a multivariate model, odds ratios for systolic hypertension were 4.16 (deceased versus living donor), 2.65 (lowest versus highest quartile of height z-score) and 2.07 (if on anti-hypertensive; yes versus no). There was significant variation in prevalent rates of hypertension between centres (P < 0.0001) that remained significant (P = 0.003) after adjustment for all the factors in the multivariate model.

CONCLUSIONS

Control of BP after kidney transplantation remains sub-optimal in paediatric centres in the UK. Just over 25% of patients remain hypertensive 5 years following transplantation. Significant differences between centres remain unexplained and may reflect differences in assessment and management of hypertension.

Blood pressure elevation in long-term survivors of pediatric liver transplantation

As pediatric liver transplant (LT) recipients come of age, additional insight into long-term medical complications of immunosuppression is warranted. The aims of this study were to estimate the prevalence of elevated blood pressure (BP) in long-term survivors of pediatric LT using the data from the Studies in Pediatric Liver Transplantation (SPLIT) database and to identify predictive factors. Patients enrolled in the BP arm of the SPLIT cohort participated in the study. All patients were of at least 5 years but ≤10 years post-LT. Automated BP measurements were obtained at anniversary visits. BP measures were classified as normal, borderline or elevated according to standard criteria. Patients taking antihypertensive medications were classified as "elevated." Eight hundred and fifteen patients participated. The prevalence of elevated BP measurements 5 to 10 years post-LT was 17.5 to 27.5%. Of total 62.5% patients presented with at least one additional elevated BP at a later follow up visit. Multivariate analysis revealed the following parameters to be predictive of elevated BP: age at transplant, steroid use at last BP measurement and cGFR at last BP measurement. Pediatric LT patients show a high prevalence of elevated BP measurements 5 to 10 years following LT, which is related to age at LT, decreased cGFR and recent steroid use.

Effects of intensive blood pressure lowering on cardiovascular and renal outcomes: a systematic review and meta-analysis

BACKGROUND

Guidelines recommend intensive blood pressure (BP) lowering in patients at high risk. While placebo-controlled trials have demonstrated 22% reductions in coronary heart disease (CHD) and stroke associated with a 10-mmHg difference in systolic BP, it is unclear if more intensive BP lowering strategies are associated with greater reductions in risk of CHD and stroke. We did a systematic review to assess the effects of intensive BP lowering on vascular, eye, and renal outcomes.

METHODS AND FINDINGS

We systematically searched Medline, Embase, and the Cochrane Library for trials published between 1950 and July 2011. We included trials that randomly assigned individuals to different target BP levels. We identified 15 trials including a total of 37,348 participants. On average there was a 7.5/4.5-mmHg BP difference. Intensive BP lowering achieved relative risk (RR) reductions of 11% for major cardiovascular events (95% CI 1%-21%), 13% for myocardial infarction (0%-25%), 24% for stroke (8%-37%), and 11% for end stage kidney disease (3%-18%). Intensive BP lowering regimens also produced a 10% reduction in the risk of albuminuria (4%-16%), and a trend towards benefit for retinopathy (19%, 0%-34%, p = 0.051) in patients with diabetes. There was no clear effect on cardiovascular or noncardiovascular death. Intensive BP lowering was well tolerated; with serious adverse events uncommon and not significantly increased, except for hypotension (RR 4.16, 95% CI 2.25 to 7.70), which occurred infrequently (0.4% per 100 person-years).

CONCLUSIONS

Intensive BP lowering regimens provided greater vascular protection than standard regimens that was proportional to the achieved difference in systolic BP, but did not have any clear impact on the risk of death or serious adverse events. Further trials are required to more clearly define the risks and benefits of BP targets below those currently recommended, given the benefits suggested by the currently available data.

Long-term risk of CKD in children surviving episodes of acute kidney injury in the intensive care unit: a prospective cohort study

BACKGROUND

The development of standardized acute kidney injury (AKI) definitions has allowed for a better understanding of AKI epidemiology, but the long-term renal outcomes of AKI in the pediatric critical care setting have not been well established. This study was designed to: (1) determine the incidence of chronic kidney disease (CKD) in children 1-3 years after an episode of AKI at a tertiary-care pediatric intensive care unit (ICU), (2) identify the proportion of patients at risk of CKD, and (3) compare ICU admission characteristics in those with and without CKD.

DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Patients admitted to the British Columbia Children's Hospital pediatric ICU from 2006-2008 with AKI, as defined by AKI Network (AKIN) criteria. Surviving patients, most with short-term recovery from their AKI, were assessed at 1, 2, or 3 years after AKI.

PREDICTORS

Severity of AKI as defined by AKIN and several ICU admission characteristics, including demographics, diagnosis, severity of illness, and ventilation data.

OUTCOMES & MEASUREMENTS

CKD was defined as the presence of albuminuria and/or glomerular filtration rate (GFR) < 60 mL/min/1.73 m2. Being at risk of CKD was defined as having a mildly decreased GFR (60-90 mL/min/1.73 m2), hypertension, and/or hyperfiltration (GFR ≥ 150 mL/min/1.73 m2).

RESULTS

The proportion of patients with AKI stages 1, 2, and 3 were 44 of 126 (35%), 47 of 126 (37%), and 35 of 126 (28%), respectively. The number of patients with CKD 1-3 years after AKI was 13 of 126 (10.3% overall; 2 of 44 [4.5%] with stage 1, 5 of 47 [10.6%] with stage 2, and 6 of 35 [17.1%] with stage 3; P = 0.2). In addition, 59 of 126 (46.8%) patients were identified as being at risk of CKD.

LIMITATIONS

Several patients identified with AKI were lost to follow-up, with the potential of underestimating the incidence of CKD.

CONCLUSIONS

In tertiary-care pediatric ICU patients, ∼10% develop CKD 1-3 years after AKI. The burden of CKD in this population may be higher with further follow-up because several patients were identified as being at risk of CKD. Regardless of the severity of AKI, all pediatric ICU patients should be monitored regularly for long-term kidney damage.

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.

Early angiotensin-converting enzyme inhibition in Alport syndrome delays renal failure and improves life expectancy

Alport syndrome inevitably leads to end-stage renal disease and there are no therapies known to improve outcome. Here we determined whether angiotensin-converting enzyme inhibitors can delay time to dialysis and improve life expectancy in three generations of Alport families. Patients were categorized by renal function at the initiation of therapy and included 33 with hematuria or microalbuminuria, 115 with proteinuria, 26 with impaired renal function, and 109 untreated relatives. Patients were followed for a period whose mean duration exceeded two decades. Untreated relatives started dialysis at a median age of 22 years. Treatment of those with impaired renal function significantly delayed dialysis to a median age of 25, while treatment of those with proteinuria delayed dialysis to a median age of 40. Significantly, no patient with hematuria or microalbuminuria advanced to renal failure so far. Sibling pairs confirmed these results, showing that earlier therapy in younger patients significantly delayed dialysis by 13 years compared to later or no therapy in older siblings. Therapy significantly improved life expectancy beyond the median age of 55 years of the no-treatment cohort. Thus, Alport syndrome is treatable with angiotensin-converting enzyme inhibition to delay renal failure and therapy improves life expectancy in a time-dependent manner. This supports the need for early diagnosis and early nephroprotective therapy in oligosymptomatic patients.

Ambulatory blood pressure monitoring in children: imperfect yet essential

There has been increasing emphasis on hypertension and early cardiovascular disease in the pediatric age group over the past decade as a result of various factors, including the obesity epidemic and publication of new clinical guidelines. A key component of identifying children and adolescents with definite or potential hypertension is proper blood pressure (BP) measurement. While ambulatory blood pressure monitoring (ABPM) offers the potential for improved detection of youths at increased cardiovascular risk, it has not been widely adopted. This commentary highlights the crucial role of ABPM in the context of current trends, while at the same time identifying the current barriers to more widespread application of this technique. Chief among these is the lack of a robust, universally applicable database of pediatric ABPM normative values. Even in the absence of ideal normative data, ABPM can and should be widely applied, and a potential algorithm for such an approach is presented.

Renin-angiotensin system inhibitors reduce the progression of mesangioproliferative glomerulonephritis: 10 year follow-up

BACKGROUND

Proteinuria is a common presentation of mesangioproliferative glomerulonephritis (MsPGN). No studies are available on the long-term effect of treatment by renin-angiotensin system (RAS) inhibitors on renal outcome in MsPGN patients. This study prospectively evaluates the effects of RAS inhibitors on renal outcome in patients with low risk MsPGN followed up for 10 years using historical patients with similar features at the time of presentation as untreated controls.

ENDPOINTS

decrease of basal proteinuria>20% and loss>20% of basal glomerular filtrate rate (GFR) at the end of first year of observation. The patients were re-evaluated bimonthly during the first year and every 6 months thereafter.

RESULTS

Twenty-five patients fulfilled the selection criteria. After one year follow-up 19 patients reached the endpoint of proteinuria and no patient reached the endpoint of GFR. No significant change in blood pressure levels (BP) and GFR was registered, by contrast daily proteinuria decreased significantly (p<0.001), falling by 29% at sixth month and 47% at the end of the follow-up. The historical control group consisted of 15 untreated patients seen between 1987 and 1992. The two-way analysis of variance for repeated measures showed greater values of GFR (p<0.001) and lower levels of daily proteinuria (p<0.001) in treated patients as compared to untreated controls.

CONCLUSIONS

This 10-year follow-up study indicates that the early treatment with RAS inhibitors at low doses favourably influences the long-term renal outcome in proteinuric patients with MsPGN. Limitations were the small sample size and lack of randomization.

Is cellular senescence important in pediatric kidney disease?

Somatic cellular senescence (SCS) describes the limited ability of cells to divide. Normally, SCS is associated with physiological aging, but evidence suggests that it may play a role in disease progression, even in young patients. Stressors such as acute injury or chronic inflammation may induce SCS, which in turn exhausts organ regenerative potential. This review summarizes what is known about SCS in the kidney with aging and disease. As most patients with chronic kidney disease (CKD) also develop cardiovascular complications, a second focus of this review deals with the role of SCS in cardiovascular disease. Also, as SCS seems to accelerate CKD and cardiovascular disease progression, developing strategies for new treatment options that overcome SCS or protect a patient from it represents an exciting challenge.

The contribution of chronic kidney disease to the global burden of major noncommunicable diseases

Noncommunicable diseases (NCDs) are the most common causes of premature death and morbidity and have a major impact on health-care costs, productivity, and growth. Cardiovascular disease, cancer, diabetes, and chronic respiratory disease have been prioritized in the Global NCD Action Plan endorsed by the World Health Assembly, because they share behavioral risk factors amenable to public-health action and represent a major portion of the global NCD burden. Chronic kidney disease (CKD) is a key determinant of the poor health outcomes of major NCDs. CKD is associated with an eight- to tenfold increase in cardiovascular mortality and is a risk multiplier in patients with diabetes and hypertension. Milder CKD (often due to diabetes and hypertension) affects 5-7% of the world population and is more common in developing countries and disadvantaged and minority populations. Early detection and treatment of CKD using readily available, inexpensive therapies can slow or prevent progression to end-stage renal disease (ESRD). Interventions targeting CKD, particularly to reduce urine protein excretion, are efficacious, cost-effective methods of improving cardiovascular and renal outcomes, especially when applied to high-risk groups. Integration of these approaches within NCD programs could minimize the need for renal replacement therapy. Early detection and treatment of CKD can be implemented at minimal cost and will reduce the burden of ESRD, improve outcomes of diabetes and cardiovascular disease (including hypertension), and substantially reduce morbidity and mortality from NCDs. Prevention of CKD should be considered in planning and implementation of national NCD policy in the developed and developing world.

Hypertension and CKD

Hypertension is found in more than 50% of pediatric patients with CKD. However, its prevalence varies according to the cause of CKD. It is relatively infrequent in children with structural disorders. Acquired renal disorders are associated with an increased prevalence of hypertension, similar to that of adults. Recent studies using ambulatory blood pressure monitoring indicate that children with CKD also have a high prevalence of masked hypertension. Similar to adults, long-standing and uncontrolled hypertension in children is associated with the progression of CKD and development of end-organ damage including early cardiomyopathy and premature atherosclerosis. Aggressive treatment of hypertension should be an essential part of pediatric CKD care, not just to prevent the development of symptomatic cardiovascular disease but also to delay progression of CKD. Recent findings from the European Effect of Strict Blood Pressure Control and ACE Inhibition on Progression of Chronic Renal Failure in Pediatric Patients (ESCAPE) trial have shown that the aggressive treatment of blood pressure, to below the 50th percentile, has even greater benefit in children with CKD, unlike results seen in adult studies.

Current perspectives on congenital obstructive nephropathy

Congenital obstructive nephropathy is the leading cause of chronic renal disease in children. As a result, it represents a tremendous societal burden in terms of morbidity and mortality, as well as in health care expenses of caring for children with chronic kidney disease and end-stage renal disease. The various diagnostic, prognostic, and therapeutic challenges associated with congenital obstructive nephropathy highlight the importance of developing effective experimental models for studying this disease process. In this review, we define the clinical entity that is congenital obstructive nephropathy, outline the current standards of diagnosis and care, and discuss the utilization of current experimental models designed to help clarify some of the clinical conundrums associated with this important disease.

Small vessels, big trouble in the kidneys and beyond: hematopoietic stem cell transplantation–associated thrombotic microangiopathy

Transplantation-associated thrombotic microangiopathy (TA-TMA) is a challenging diagnosis after hematopoietic stem cell transplantation. Although endothelial injury represents the final common pathway of disease, the exact pathophysiology of TA-TMA remains unclear. Potential causes include infections, chemotherapy, radiation, and calcineurin inhibitors. Recent literature addresses the roles of cytokines, graft-versus-host disease, the coagulation cascade, and complement in the pathogenesis of TA-TMA. Current diagnostic criteria are unsatisfactory, because patients who have received a transplant can have multiple other reasons for the laboratory abnormalities currently used to diagnose TA-TMA. Moreover, our lack of understanding of the exact mechanism of disease limits the development and evaluation of potential treatments. Short- and long-term renal complications contribute to TA-TMA's overall poor prognosis. In light of these challenges, future research must validate novel markers of disease to aid in early diagnosis, guide current and future treatments, prevent long-term morbidity, and improve outcomes. We focus on TA-TMA as a distinct complication of hematopoietic stem cell transplantation, emphasizing the central role of the kidney in this disease.

Effect of diet, enalapril, or losartan in post-diarrheal hemolytic uremic syndrome nephropathy

Proteinuria is the main indicator of renal disease progression in many chronic conditions. There is currently little information available on the efficacy, safety, and individual tolerance of patients with post-diarrheal hemolytic uremic syndrome (D+ HUS) nephropathy to therapies involving diet, enalapril, or losartan. A multicenter, double-blind, randomized controlled trail was conducted to evaluate the effect of a normosodic-normoproteic diet (Phase I) and the effect of normosodic-normoproteic diet plus enalapril (0.18-0.27 mg/kg/day) or losartan (0.89-1.34 mg/kg/day) (Phase II) on children with D+ HUS, normal renal function, and persistent, mild (5.1-49.9 mg/kg/day) proteinuria. Dietary intervention reduced the mean protein intake from 3.4 to 2.2 mg/kg/day. Of 137 children, proteinuria normalized in 91 (66.4 %) within 23-45 days; the remaining 46 patients were randomized to diet plus placebo (group 1, n = 16), plus losartan (group 2, n = 16), or enalapril (group 3, n = 14). In groups 1, 2, and 3, proteinuria was reduced by 30.0, 82.0, and 66.3%, respectively, and normalized in six (37.5%), three (81.3%), and 11 (78.6%) patients, respectively (χ(2)= 8.9, p = 0.015). These results suggest that: (1) a normosodic-normoproteic diet can normalize proteinuria in the majority of children with D+ HUS with mild sequelae, (2) the addition of enalapril or losartan to such dietary restrictions of protein further reduces proteinuria, and (3) these therapeutic interventions are safe and well tolerated. Whether these short-term effects can be extended to the long-term remains to be demonstrated.

Insights from the Chronic Kidney Disease in Children (CKiD) study

Over the last 5 years, the Chronic Kidney Disease in Children (CKiD) prospective cohort study has enrolled close to 600 children ages 1 to 16 years with mild to moderate chronic kidney disease (CKD). The main purpose of this interim report is to review the initial cross-sectional data and conclusions derived from the clinical studies conducted within CKiD in the context of findings from other pediatric CKD and end-stage renal disease (ESRD) registry and cohort studies. In particular, special emphasis was placed on studying four aspects of chronic kidney disease in children, including the identification of risk factors related to disease progression, the impact of CKD on neurocognition and quality of life (QoL), the cardiovascular morbidity associated with CKD, and identifying the causes and effects of growth failure in the context of mild to moderate kidney failure.

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.

No difference in meeting hemoglobin and albumin targets for dialyzed children with urologic disorders

Urologic disorders are the most common cause of chronic kidney disease in children. To determine whether children with urologic etiology of end-stage renal disease (ESRD) fare better than children with ESRD from other causes while on dialysis, we conducted a cross-sectional study of children <18 years receiving peritoneal and hemodialysis in the United States using data from the Centers for Medicare & Medicaid Services 2005 ESRD CPM Project. We compared baseline demographics and the study groups. In multivariate logistic regression analysis of 1,286 subjects, we assessed whether children with urologic disorders had a higher odds of meeting adult KDOQI targets for hemoglobin levels ≥11 g/dl and albumin ≥3.5 BCG/3.2 BCP g/dl. We conducted a subset analysis of 1,136 patients to examine the impact of erythropoietin on hemoglobin targets. Our results did not reveal differences in achievement of adult hemoglobin targets (adjusted OR: 1.27; p value 0.09; CI: 0.97-1.66) or in the subset analysis with erythropoietin (adjusted OR: 1.32; p value 0.06; CI: 0.98-1.78) or albumin targets (adjusted OR: 1.22; p value 0.21; CI: 0.90-1.65) in adjusted analyses. Due to our study's limitations, it is difficult to determine whether this may result from treatment prior to dialysis initiation or treatment effect of dialysis rather than underlying diagnosis.

Proteinuria in special populations: pregnant women and children

Proteinuria is the hallmark of glomerular kidney disease. It is used diagnostically to follow disease progression and to determine response to therapy. Thus, it is necessary to have an understanding of the mechanisms of proteinuria and the limitations to its accurate assessment in special populations. In this article, we review 2 special populations--pregnant women and children--providing insight into their unique circumstances that require consideration when assessing proteinuria.

Diagnosis and treatment of hypertension in children

Hypertension is a global problem, affecting both developed and developing nations. In children and adolescents, hypertension has gained ground in cardiovascular medicine, thanks to the progress made in several areas of pathophysiologic and clinical research. Childhood hypertension is often asymptomatic and is easily missed, even by health professionals. Target organ damage is detectable in children and adolescents. Management of hypertension includes lifestyle changes and pharmacologic treatment. In the case of secondary hypertension, pharmacologic treatment usually is required. In essential hypertension, assessment of early organ damage provides a useful tool for treatment decisions.

Clinical utility of valsartan in the treatment of hypertension in children and adolescents

Valsartan is a potent antagonist of the type 1 angiotensin receptor (AT(1)). By blocking the actions of angiotensin II on the AT(1), it inhibits vasoconstriction and synthesis of aldosterone thus lowering systemic blood pressure. Valsartan has been approved by the FDA for the treatment of hypertension in children aged 6 years and older. Valsartan can be dosed once a day with a sustained 24-hour effect on blood pressure reduction. The starting dose recommended in children is 1.3 mg/kg once daily (maximum 40 mg) which needs adjustment according to blood pressure response (dose range 1.3-2.7 mg/kg daily; up to 160 mg). A suspension form (4 mg/mL) is available for children who cannot swallow tablets. In patients aged 6 to 16 years, valsartan treatment (from a low dose of 10-20 mg to a high dose of 80-160 mg) resulted in dose-dependent reductions of 7.9-11.5 mmHg in systolic blood pressure and 4.6-7.4 mmHg in diastolic blood pressure. In 1- to 5-year-olds, valsartan (from a low dose of 5-10 mg to a high dose of 40-80 mg) reduced the systolic blood pressure by 8.4-8.6 mmHg and the diastolic blood pressure by 5.5 mmHg. Similar to adults and other antihypertensive medications, the most frequent side effect in children subsequent to valsartan use is headache. Current studies have not shown adverse effects on linear growth, weight gain, head growth, or development in children aged 1 to 5 years subsequent to valsartan use. Based on limited pediatric data, valsartan appears to be well tolerated and efficacious in reducing elevated blood pressure.

Inefficacy interim monitoring procedures in randomized clinical trials: the need to report

If definitive evidence concerning treatment effectiveness becomes available from an ongoing randomized clinical trial, then the trial could be stopped early, with the public release of results benefiting current and future patients. However, stopping an ongoing trial based on accruing outcome data requires methodological rigor to preserve validity of the trial conclusions. This has led to the use of formal interim monitoring procedures, which include inefficacy monitoring that will stop a trial early when the experimental treatment appears not to be working. For participants, inefficacy monitoring is especially important as it ensures that they are not being treated worse than if they had not enrolled on the trial. We discuss the importance of reporting with trial results the formal interim inefficacy monitoring guidelines that were utilized, and, if none were used, the reasons for their absence. A survey of two leading medical journals suggests that this is not current practice.

Are we ready to use aliskiren in children?

The objective of this case series was to review the safety and efficacy of aliskiren in combination with losartan in pediatric chronic kidney disease (CKD) patients. This was a retrospective study in which the medical files of all patients who had received aliskiren were reviewed. Four patients were identified between 5 and 18 years of age who had received aliskiren and losartan for the reduction of refractory proteinuria. While proteinuria was reduced in all four of these patients by 45, 96, 53, and 64%, respectively, three patients experienced side effects requiring changes in the aliskiren dose. A significant side effect occurred in the patient with CKD stage 3 who suffered accelerated loss of kidney function leading to dialysis after only a short course of therapy. The data from this preliminary trial strongly suggest that clinicians should exercise caution when prescribing aliskiren in combination with losartan until appropriate pediatric trials establish dosing, efficacy, and safety.

Acute reversible changes of brachial-ankle pulse wave velocity in children with acute poststreptococcal glomerulonephritis

Acute poststreptococcal glomerulonephritis (APSGN) is the most common form of postinfectious nephritis worldwide. The relationship between inflammation and arterial stiffness has been described elsewhere, but there have been no studies that have analyzed the association between arterial compliance and APSGN. The aim of this study is to assess brachial-ankle pulse wave velocity (baPWV) in pediatric patients with APSGN, and the value of baPWV in predicting the outcome. We evaluated 16 children diagnosed with APSGN, 11 children with acute pyelonephritis (APN), and 25 healthy individuals in our hospital. The baPWV of all candidates was measured. In addition, follow-up of the APSGN group was conducted for baPWV, blood pressure and biochemical parameters. Significantly increased baPWV was observed in the APSGN group at initial diagnosis (P<0.001), in comparison with the APN group and healthy controls. Of these, 13 patients received sequential measurement of baPWV. Overwhelmingly, baPWV was rapidly normalized in 11 patients, whereas 2 boys presented with persistently higher baPWV. During the follow-up period of 2-3 years, both had consistency of proteinuria, and consequently, they progressed to either chronic renal insufficiency or end-stage renal disease (ESRD). In conclusion, the results demonstrate that APSGN involves not only the kidney, but also the arteries outside the kidney. Acute arterial stiffness might persist in patients who do not recover, but develop chronic kidney disease (CKD).