Blood pressure in children with chronic kidney disease: a report from the Chronic Kidney Disease in Children study

Hypertension and childhood stroke

Cerebrovascular disease (stroke) is one of the ten leading causes of death in children and adolescents. Multiple etiologies, from arteriopathies to prothrombic states, can cause stroke in youth. In adult stroke, hypertension has been shown to be the single most important modifiable risk factor. Although hypertension has not been strongly identified as a risk factor in childhood stroke to date, there is preliminary evidence that suggests that hypertension may also be associated with stroke in children. In this review, we summarize the literature that may link hypertension to stroke in the young. We have identified a series of barriers and limitations in the fields of pediatric hypertension and pediatric neurology that might explain why hypertension has been overlooked in childhood stroke. We suggest that hypertension may be a relevant risk factor that, alone or in combination with other multiple factors, contributes to the development of stroke in children. Currently, there are no consensus guidelines for the management of post-stroke hypertension in children. Thus, we recommend that blood pressure be assessed carefully in every child presenting with acute stroke in order to better understand the effects of hypertension in the development and the outcome of childhood stroke. We suggest a treatment algorithm to help practitioners manage hypertension after a stroke.

The CKiD study: overview and summary of findings related to kidney disease progression

The Chronic Kidney Disease in Children (CKiD) cohort study is a North American (USA and Canada) multicenter, prospective study of children with chronic kidney disease (CKD). The original aims of the study were (1) to identify novel risk factors for CKD progression; (2) to measure the impact of kidney function decline on growth, cognition, and behavior; and (3) to characterize the evolution of cardiovascular disease risk factors. CKiD has developed into a national and international resource for the investigation of a variety of factors related to CKD in children. This review highlights notable findings in the area of CKD progression and outlines ongoing opportunities to enhance understanding of CKD progression in children. CKiD's contributions to the clinical care of children with CKD include updated and more accurate glomerular filtration rate estimating equations for children and young adults, and resources designed to help estimate the CKD progression timeline. In addition, results from CKiD have strengthened the evidence that treatment of hypertension and proteinuria should continue as a primary strategy for slowing the rate of disease progression in children.

A reappraisal of the prevalence of pediatric hypertension through a nationwide database in Taiwan

Hypertension in childhood and adolescence is associated with adult cardiovascular morbidity and mortality. However, the reported prevalence of pediatric hypertension varies considerably. We conducted a pioneer nationwide population-based study to investigate the prevalence of hypertension among children and adolescents. Pediatric patients who had been diagnosed with hypertension between 2000 and 2013 were selected from the National Health Insurance Research Database in Taiwan. Other metabolic syndrome-related diseases that would increase cardiovascular risk, including diabetes mellitus (DM), hyperlipidemia, and obesity, were also retrieved for further evaluation. In total, 10,364 children and adolescents diagnosed with hypertension were identified. The prevalence of pediatric hypertension in Taiwan ranged from 0.19 to 0.38 per 1000 children and adolescents between 2000 and 2013. Essential hypertension was most commonly coded (90.6%), which was much more than secondary hypertension (14.3%). Children and adolescents with hypertension were often associated with DM, hyperlipidemia, and obesity, with the odds ratios as 14.05 (95% confidence interval (CI) 11.74-16.81, p < 0.001), 10.65 (95% CI 9.48-11.97, p < 0.001), and 19.08 (95% CI 15.65-23.26, p < 0.001), respectively. To improve lifelong cardiovascular health, our results emphasize the importance of early proper recognition and suitable management of hypertension, as well as metabolic syndrome-related diseases, among children and adolescents.

Promoting cardiovascular health post-transplant through early diagnosis and adequate management of hypertension and dyslipidemia

Despite correction of underlying solid organ failure by transplantation, pediatric transplant recipients still have increased mortality rates compared to the general pediatric population, in part due to increased cardiovascular risk. In particular, pediatric kidney and non-kidney transplant recipients with chronic kidney disease have significant cardiovascular risk that worsens with declining kidney function. Biomarkers associated with future cardiovascular risk such as casual and ambulatory hypertension, dyslipidemia, vascular stiffness and calcification, and left ventricular hypertrophy can be detected throughout the post-transplant period and in patients with stable kidney function. Among these, hypertension and dyslipidemia are two potentially modifiable cardiovascular risk factors that are highly prevalent in kidney and non-kidney pediatric transplant recipients. Standardized approaches to appropriate BP measurement and lipid monitoring are needed to detect and address these risk factors in a timely fashion. To achieve sustained improvement in cardiovascular health, clinicians should partner with patients and their caregivers to address these and other risk factors with a combined approach that integrates pharmacologic with non-pharmacologic approaches. This review outlines the scope and impact of hypertension and dyslipidemia in pediatric transplant recipients, with a particular focus on pediatric kidney transplantation given the high burden of chronic kidney disease-associated cardiovascular risk. We also review the current published guidelines for monitoring and managing abnormalities in blood pressure and lipids, highlighting the important role of therapeutic lifestyle changes in concert with antihypertensive and lipid-lowering medications.

A phase 3 randomized clinical trial using a once-weekly glucagon-like peptide-1 receptor agonist in adolescents and young adults with hypothalamic obesity

AIM

To evaluate the efficacy, safety and tolerability of a glucagon-like peptide-1 receptor agonist (GLP-1 RA) in patients with hypothalamic obesity (HO).

MATERIALS AND METHODS

A two-arm, randomized, multicentre, double-blind, placebo-controlled trial was conducted in 10- to 25-year-olds with hypothalamic injury following intracranial tumour and HO. Participants were randomized to once-weekly subcutaneous injections of a GLP-1 RA exenatide 2 mg (ExQW) or placebo for 36 weeks. The primary efficacy endpoint was 36-week % change in body mass index (BMI). Secondary outcomes included change in body composition (by dual energy x-ray absorptiometry).

RESULTS

Forty-two participants were randomized to ExQW (n = 23) or placebo (n = 19). Participants were 5 ± 2 years (mean ± SD) postdiagnosis and development of HO (BMI 37.3 ± 7.1 kg/m² ). In intention-to-treat analysis, the effect of 36-week ExQW vs. placebo on % Δ BMI was not significant (estimated treatment difference -1.7 ± 1.8%, 95% CI -4.1 to 0.6%, P = .40); however, total body fat mass was reduced (estimated treatment difference -3.1 ± 1.4 kg, 95% CI -5.7 to -0.4 kg, P = .02). There was a significant reduction in waist circumference (estimated effect of treatment -3.5 [95% CI -5.5 to -1.6] cm, P = .004). All patients treated with placebo increased % of adipose tissue, while 50% treated with ExQW had reductions (P < .001). Mean HbA1c, glucose tolerance and serum lipids did not change significantly with therapy. ExQW was well tolerated. The most frequent adverse events were transient gastrointestinal disturbances (ExQW vs. placebo: nausea 6/23 vs. 3/18, vomiting 4/23 vs. 4/18 and diarrhoea 7/23 vs. 3/18).

CONCLUSIONS

GLP-1 RAs are a promising and safe treatment to improve or stabilize HO in children and young adults.

Cardiovascular Disease Risk in Children With Chronic Kidney Disease: Impact of Apolipoprotein C-II and Apolipoprotein C-III

Cardiovascular disease (CVD) is an evolving process that begins in the early stages of chronic kidney disease (CKD) in children. Several surrogate markers, such as ambulatory blood pressure monitoring (ABPM), left ventricular (LV) mass, and arterial stiffness assessment, allow for the early detection of subclinical CVD in pediatric CKD. Four groups of plasma samples (n = 3/group) from congenital anomalies of the kidney and urinary tract (CAKUT), as well as non-CAKUT patients with or without BP abnormalities, were studied to screen differentially expressed proteins using isobaric tags for relative and absolute protein quantification (iTRAQ)-based proteomics. As a result, 20 differentially expressed proteins associated with hypertension in children with CKD were discovered. Among them, apolipoprotein C-II (apoC-II) was found to have the highest abundance among the CKD patients with hypertension. As such, we hypothesized that apoC-II and apolipoprotein C-III (apoC-III) levels were related to BP abnormalities and CVD in children suffering from mild-to-moderate CKD. We examined their associations with surrogate markers of CV risk in 88 pediatric patients with CKD stages G1-G4. Children with CKD stages G2-G4 had a higher plasma apoC-II level than G1 patients (6.35 vs. 5.05 mg/dl, p < 0.05). We observed that ABPM abnormalities, LV mass, and arterial stiffness parameters were greater in CKD children who had stages G2-G4 than in those who had stage G1 (all p < 0.05). Plasma levels of apoC-II and apoC-III were positively correlated with total cholesterol, triglyceride, and low-density lipoprotein (LDL) (all p < 0.001). In multivariate linear regression analyses, apoC-II was correlated with a high LV mass index and an abnormal ABPM profile, and apoC-III was correlated with 24-h hypertension (r = 0.303, p = 0.003) and asleep hypertension (r = 0.379, p < 0.001). Early evaluations of apoC-II and apoC-III, ABPM, and surrogate markers of CV risk will aid in early preventative interventions to reduce the risk of CV in youths suffering from CKD.

Secondary Hypertension in Children and Adolescents: Novel Insights

Hypertension is a significant risk factor for cardiovascular morbidity and mortality, not only in adults, but in youths also, as it is associated with long-term negative health effects. The predominant type of hypertension in children is the secondary hypertension, with the chronic kidney disease being the most common cause, however, nowadays, there is a rising incidence of primary hypertension due to the rising incidence of obesity in children. Although office blood pressure has guided patient management for many years, ambulatory blood pressure monitoring provides useful information, facilitates the diagnosis and management of hypertension in children and adolescents, by monitoring treatment and evaluation for secondary causes or specific phenotypes of hypertension. In the field of secondary hypertension, there are numerous studies, which have reported a strong association between different determinants of 24-hour blood pressure profile and the underlying cause. In addition, in children with secondary hypertension, ambulatory blood pressure monitoring parameters offer the unique advantage to identify pediatric low- and high-risk children for target organ damage. Novel insights in the pathogenesis of hypertension, including the role of perinatal factors or new cardiovascular biomarkers, such as fibroblast growth factor 23, need to be further evaluated in the near future.

Left-ventricular diastolic dysfunction in Korean children with chronic kidney disease: data from the KNOW-Ped CKD study

Background

Cardiovascular disease (CVD) is the most common cause of mortality in pediatric chronic kidney disease (CKD) patients. Left ventricular (LV) hypertrophy (LVH) is associated with LV diastolic dysfunction (LVDD) development and is used as an early marker of CVD in pediatric CKD. This study aimed to assess the prevalence and risk factors of LVDD and the association between LVH and LVDD in Korean pediatric CKD patients.

Methods

Data were collected using the baseline data of the Korean cohort study for outcome in patients with pediatric chronic kidney disease, a nationwide, 10-year, prospective, observational cohort study of pediatric CKD. A total of 244 patients were included in the final analysis. Two-dimensional echocardiography and tissue Doppler images were used to evaluate LVH and LVDD. LVH was defined as an LV mass index (LVMI) ≥38 g/m^2.7 and LV-wall thickness z-score > 1.64. LVDD was defined as a mitral peak velocity of early filling to early diastolic mitral annular velocity (E/E’) > 14. Univariate and multivariate logistic regression analyses were performed to evaluate risk factors of LVDD.

Results

In this study, the male-to-female ratio was 2.2 (168:76) and median age was 11.2 years. The average estimated glomerular filtration rate was 57.4 ml/min/1.73 m², and no patients received renal replacement therapy. The mean value of LVMI and E/E’ was 37.0 g/m^2.7 and 7.4, respectively. The prevalence of LVH was 40.1 and 17.4% by LVMI ≥38 g/m^2.7 and LV-wall thickness z-score, respectively. The prevalence of LVDD was 4.5%, and patients with LVH showed greater risk of LVDD (odds ratio 7.3, p = 0.012). In the univariate analysis, young age, low hemoglobin level, higher LVMI, and higher LV-wall thickness z-score were associated with LVDD. In the multivariate analysis, young age, low hemoglobin level, and higher LV-wall thickness z-score were independently associated with LVDD.

Conclusion

This study shows that LVH patients have a greater risk of LVDD and that anemia is the only modifiable risk factor for LVDD in Korean pediatric CKD patients.

Serially assessed bisphenol A and phthalate exposure and association with kidney function in children with chronic kidney disease in the US and Canada: A longitudinal cohort study

BACKGROUND

Exposure to environmental chemicals may be a modifiable risk factor for progression of chronic kidney disease (CKD). The purpose of this study was to examine the impact of serially assessed exposure to bisphenol A (BPA) and phthalates on measures of kidney function, tubular injury, and oxidative stress over time in a cohort of children with CKD.

METHODS AND FINDINGS

Samples were collected between 2005 and 2015 from 618 children and adolescents enrolled in the Chronic Kidney Disease in Children study, an observational cohort study of pediatric CKD patients from the US and Canada. Most study participants were male (63.8%) and white (58.3%), and participants had a median age of 11.0 years (interquartile range 7.6 to 14.6) at the baseline visit. In urine samples collected serially over an average of 3.0 years (standard deviation [SD] 1.6), concentrations of BPA, phthalic acid (PA), and phthalate metabolites were measured as well as biomarkers of tubular injury (kidney injury molecule-1 [KIM-1] and neutrophil gelatinase-associated lipocalin [NGAL]) and oxidative stress (8-hydroxy-2'-deoxyguanosine [8-OHdG] and F2-isoprostane). Clinical renal function measures included estimated glomerular filtration rate (eGFR), proteinuria, and blood pressure. Linear mixed models were fit to estimate the associations between urinary concentrations of 6 chemical exposure measures (i.e., BPA, PA, and 4 phthalate metabolite groups) and clinical renal outcomes and urinary concentrations of KIM-1, NGAL, 8-OHdG, and F2-isoprostane controlling for sex, age, race/ethnicity, glomerular status, birth weight, premature birth, angiotensin-converting enzyme inhibitor use, angiotensin receptor blocker use, BMI z-score for age and sex, and urinary creatinine. Urinary concentrations of BPA, PA, and phthalate metabolites were positively associated with urinary KIM-1, NGAL, 8-OHdG, and F2-isoprostane levels over time. For example, a 1-SD increase in ∑di-n-octyl phthalate metabolites was associated with increases in NGAL (β = 0.13 [95% CI: 0.05, 0.21], p = 0.001), KIM-1 (β = 0.30 [95% CI: 0.21, 0.40], p < 0.001), 8-OHdG (β = 0.10 [95% CI: 0.06, 0.13], p < 0.001), and F2-isoprostane (β = 0.13 [95% CI: 0.01, 0.25], p = 0.04) over time. BPA and phthalate metabolites were not associated with eGFR, proteinuria, or blood pressure, but PA was associated with lower eGFR over time. For a 1-SD increase in ln-transformed PA, there was an average decrease in eGFR of 0.38 ml/min/1.73 m2 (95% CI: -0.75, -0.01; p = 0.04). Limitations of this study included utilization of spot urine samples for exposure assessment of non-persistent compounds and lack of specific information on potential sources of exposure.

CONCLUSIONS

Although BPA and phthalate metabolites were not associated with clinical renal endpoints such as eGFR or proteinuria, there was a consistent pattern of increased tubular injury and oxidative stress over time, which have been shown to affect renal function in the long term. This raises concerns about the potential for clinically significant changes in renal function in relation to exposure to common environmental toxicants at current levels.

Isolated nocturnal and isolated daytime hypertension associate with altered cardiovascular morphology and function in children with chronic kidney disease: findings from the Cardiovascular Comorbidity in Children with Chronic Kidney Disease study

INTRODUCTION

Prevalence of isolated nocturnal hypertension (INH) and isolated daytime hypertension (IDH) is around 10% in adults. Data in children, especially in chronic kidney disease (CKD), are lacking. The aim of this cross-sectional multicenter cohort study was to define the prevalence of INH and IDH and its association with cardiovascular morphology and function, that is, pulse wave velocity (PWV), carotid intima-media thickness (cIMT), or left ventricular mass index (LVMI) in children with CKD.

METHODS

Ambulatory blood pressure (BP) monitoring profiles were analyzed in 456 children with CKD stages III-V participating in the Cardiovascular Comorbidity in Children with Chronic Kidney Disease Study (64.3% males, 71.3% congenital anomaly of the kidney and urinary tract, age 12.5 ± 3.2 years, estimated glomerular filtration rate 29 ± 12 ml/min per 1.73 m). Baseline PWV, cIMT, and LVMI were compared in normotension, INH, IDH, or sustained 24-h hypertension.

RESULTS

Prevalence of sustained hypertension was 18.4%, of INH 13.4%, and of IDH 3.7%. PWV SDS (SD score) and cIMT SDS were significantly higher in sustained hypertension and INH, and PWV SDS was significantly higher in IDH, compared with normotension. LVMI was significantly increased in sustained hypertension, but not in INH or IDH. Determinants of INH were smallness for gestational age, older age, higher height SDS and parathyroid hormone, and shorter duration of CKD. In logistic regression analysis, day/night-time hypertension or ambulatory BP monitoring pattern (normal, INH, IDH, sustained hypertension) were independently associated with cardiovascular outcome measures: elevated night-time BP was associated with increased cIMT, PWV, and left ventricular hypertrophy; INH was associated with cIMT.

CONCLUSION

INH is present in almost one out of seven children with predialysis CKD; INH and nocturnal hypertension in general are associated with alterations of arterial morphology and function.

The Improving Renal Outcomes Collaborative: Blood Pressure Measurement in Transplant Recipients

BACKGROUND AND OBJECTIVES

Hypertension is highly prevalent in pediatric kidney transplant recipients and contributes to cardiovascular death and graft loss. Improper blood pressure (BP) measurement limits the ability to control hypertension in this population. Here, we report multicenter efforts from the Improving Renal Outcomes Collaborative (IROC) to standardize and improve appropriate BP measurement in transplant patients.

METHODS

Seventeen centers participated in structured quality improvement activities facilitated by IROC, including formal training in quality improvement methods. The primary outcome measure was the proportion of transplant clinic visits with appropriate BP measurement according to published guidelines. Prospective data were analyzed over a 12-week pre-intervention period and a 20-week active intervention period for each center and then aggregated as of the program-specific start date. We used control charts to quantify improvements across IROC centers. We applied thematic analysis to identify patterns and common themes of successful interventions.

RESULTS

We analyzed data from 5392 clinic visits. At baseline, BP was measured and documented appropriately at 11% of visits. Center-specific interventions for improving BP measurement included educating clinic staff, assigning specific team member roles, and creating BP tracking tools and alerts. Appropriate BP measurement improved throughout the 20-week active intervention period to 78% of visits.

CONCLUSIONS

We standardized appropriate BP measurement across 17 pediatric transplant centers using the infrastructure of the IROC learning health system and substantially improved the rate of appropriate measurement over 20 weeks. Accurate BP assessment will allow further interventions to reduce complications of hypertension in pediatric kidney transplant recipients.

Blood pressure in children with chronic kidney disease: lessons learned from the Chronic Kidney Disease in Children Cohort Study

Cardiovascular disease (CVD) is common among children and adolescents with chronic kidney disease (CKD) and end-stage kidney disease (ESRD). However, the early accrual of CVD risk factors in children with CKD has not been well studied. The Chronic Kidney Disease in Children (CKiD) Study, a multicenter, prospective cohort study of children with mild-to-moderate CKD at study entry counts among its primary aims investigation of the drivers of CVD risk in this population. As the most prevalent CVD risk factor in children with CKD, blood pressure (BP) has been a major focus of investigation for the CKiD Study Group. Over the first 15 years of the study, landmark publications have better defined the prevalence of hypertension, the frequency with which it is under-recognized and thus undertreated, and the consequences of elevated BP in this cohort. The purpose of this review is to summarize the contributions made by the CKiD Study in advancing knowledge of BP in this high-risk population, and to highlight areas in need of further study.

Bicarbonate, blood pressure, and executive function in pediatric CKD-is there a link?

BACKGROUND

In adult chronic kidney disease (CKD), metabolic acidosis is associated with diminished cognition, notably executive function (EF). Data from the Chronic Kidney Disease in Children (CKiD) study demonstrate a risk for impairment of EF, a finding associated with heightened blood pressure variability (BPV). We sought to determine whether low serum bicarbonate is also associated with performance on tests of EF in pediatric CKD and to investigate potential interaction with BPV.

METHODS

CKiD participants with serum bicarbonate, blood pressure, and selected cognitive measurements available were evaluated. An EF summary score was derived from scores on the Delis-Kaplan Executive Function System, Conners' Continuous Performance Test, and Digit Span Backwards subtest from the Wechsler Intelligence Scale for Children-IV-Integrated. Parents completed the Behavioral Rating Inventory of Executive Function (BRIEF) to yield a Global Executive Composite (GEC) score. Linear mixed models with bicarbonate and hypertension as predictors and linear regression with bicarbonate and BPV were used to predict EF level.

RESULTS

Data were available for 865 children. Twenty-two percent had low bicarbonate (CO₂ ≤ 20 mmol/L) at baseline. On multivariate analysis, there was no relationship between bicarbonate, hypertension, and EF. There was no significant CO₂×hypertension interaction found. A significant interaction (p = 0.01) between high CO₂ (≥ 26 mmol/L) and BPV was detected in the model with GEC as the EF outcome, indicating that while higher BPV was associated with worse EF in the low and normal CO₂ groups, higher BPV was associated with better EF in the high CO₂ group.

CONCLUSIONS

Our analyses revealed an interaction between one measure of BPV and low bicarbonate on neurocognition in pediatric CKD, suggesting a potential role for control of both bicarbonate and blood pressure in preserving cognition in early CKD. Further research is needed to confirm and further define this association.

Urolithiasis, growth and blood pressure in childhood: A case-control study

BACKGROUND & AIMS

Kidney stone is a life-threatening disease with subsequent complications, especially in children who overtake this disease in early ages. This study assessed the effect of kidney stone history on current blood pressure and growth parameters of children.

METHODS

A two hundred children with (n = 100) and without (n = 100) a history of urolithiasis from Pediatric Urology clinics at the Aliasghar hospital, Tehran, Iran, participated in this case-control study. Several demographic data, height, weight, body mass index (BMI), BMI for age and blood pressure index were measured as the primary outcomes.

RESULTS

type of birth and infancy feeding, carbohydrate and energy intake were significantly different between the two groups (P = 0.008, 0.002, 0.03 and < 0.001 respectively). Ordinal logistic regression analysis showed that the current weight (P = 0.001) and BMI for age (P = 0.02) of the stone formers were lower than the non-stone formers, while no significant association found between the blood pressure or current height and the history of urolithiasis.

CONCLUSION

Our findings suggest that childhood urolithiasis has no significant effect on growth failure and blood pressure in childhood but it has a little impact on weight and BMI for age in older ages.

An Automated Blood Pressure Display for Self-Measurement in Patients With Chronic Kidney Disease (iHealth Track): Device Validation Study

BACKGROUND

Hypertension is a global public health issue and is closely related to chronic kidney disorder (CKD). In people with CKD, strict monitoring of blood pressure is an important part of therapy.

OBJECTIVE

The aim of this research was to validate the iHealth Track blood pressure monitoring device for patients with CKD according to the European Society of Hypertension International Protocol 2010 (ESH-IP2).

METHODS

In total, 33 patients who received hemodialysis in Plasencia participated in the study. There were 9 successive measurements made, which conformed to the ESH-IP2. We calculated the differences between the standard reference device (Omron M3 Intellisense) and the test device (iHealth Track) for blood pressure and heart rate values. For 99 total comparisons of paired measurements, we classified differences into various categories (≤5 mmHg, ≤10 mmHg, and ≤15 mmHg for blood pressure; ≤3, ≤5, and ≤8 beats per minute for heart rate).

RESULTS

In 90 of 99 systolic blood pressure and 89 of 99 diastolic blood pressure comparisons between the devices, measurement differences were within 5 mmHg. In 81 of 99 heart rate comparisons between the devices, measurement differences were within 3 beats per minute. The mean differences between the test and reference standard measurements were 3.27 (SD 2.99) mmHg for systolic blood pressure, 3.59 (SD 4.55) mmHg for diastolic blood pressure, and 2.18 (SD 2.75) beats per minute for heart rate. We also observed that for both systolic and diastolic blood pressure, 31 of 33 participants had at least two of three comparisons between the devices with measurement differences less than 5 mmHg. For heart rate, 28 of 33 patients had at least two of three comparisons between the devices with measurement differences less than 3 beats per minute.

CONCLUSIONS

To our knowledge, this is the first study to show that iHealth Track meets the requirements of the ESH-IP2 in patients with CKD. Therefore, the iHealth Track is suitable for use in renal patients.

New guidelines for the diagnosis, evaluation, and treatment of pediatric hypertension

Childhood hypertension has become a significant public health problem due to increased prevalence in recent decades. High blood pressure causes increased mortality and morbidity in childhood, precedes adult hypertension, and causes increased cardiovascular events in adulthood. These concerns have led to an update of guidelines about childhood hypertension by the European Society of Hypertension in 2016 and the American Academy of Hypertension in 2017. This review highlights the important developments in these guidelines and recent literature about childhood hypertension in terms of diagnosis, prevalence, risk factors, diagnostic tools, prevention and management.

Oxidant stress and renal function among children with chronic kidney disease: a repeated measures study

It is hypothesized that chronic kidney disease (CKD) induces oxidant stress which contributes to the decline in kidney function. However, few studies have incorporated longitudinal designs and no studies have investigated this association among children. Using data from the Chronic Kidney Disease in Children (CKiD) study, we examined longitudinal associations between urinary biomarkers of oxidant stress, 8-OH deoxyguanosine (8-OHdG) and F2-isoprostane, and measures of renal function and blood pressure among children with CKD. Baseline levels of 8-OHdG were positively associated with estimated glomerular filtration rate (eGFR) over time and a log-unit increase in baseline 8-OHdG predicted a 5.68 ml/min/1.73 m2 increase in eGFR (95% Confidence Interval (CI): 3.75, 7.61). This association was attenuated when longitudinal measures of 8-OHdG were analyzed in relation to longitudinal eGFR (per log-unit increase in 8-OHdG, β = 0.81, 95% CI: 0.22, 1.39). Baseline 8-OHdG concentrations were also associated with decreased proteinuria over time, as measured by urinary protein:creatinine ratio. In addition, F2-isoprostane concentrations were associated with increases in eGFR, but only when baseline levels (vs. longitudinal levels) were considered in relation to longitudinal eGFR. There were no significant associations between either 8-OHdG or F2-isoprostane and blood pressure over time. Urinary measures of oxidant stress are not associated with worsening GFR over time. Our findings suggest that excretion of these biomarkers may be influenced by changes in glomerular and tubular function in varying patterns, which would limit their value in evaluating the impact of oxidant stress on CKD progression in children.

Association of Time-Varying Blood Pressure With Chronic Kidney Disease Progression in Children

IMPORTANCE

Optimal blood pressure (BP) management in children with chronic kidney disease (CKD) slows progression to end-stage renal disease. Studies often base progression risk on a single baseline BP measurement, which may underestimate risk.

OBJECTIVE

To determine whether time-varying BP measurements are associated with a higher risk of progression of CKD than baseline BP measurements.

DESIGN, SETTING, AND PARTICIPANTS

The ongoing longitudinal, prospective cohort study Chronic Kidney Disease in Children (CKID) recruited children from January 19, 2005, through March 19, 2014, from pediatric nephrology centers across North America, with data collected at annual study visits. Participants included children aged 1 to 16 years with a diagnosis of CKD and a glomerular filtration rate (GFR) of 30 to 90 mL/min/1.73 m2. Data were analyzed from February 11, 2005, through February 13, 2018.

EXPOSURES

Office BP measurement classified as less than 50th percentile, 50th to less than 90th percentile, or at least 90th percentile. Blood pressure categories were treated as time fixed (baseline) or time varying (updated at each visit) in models.

MAIN OUTCOMES AND MEASURES

A composite renal outcome (50% GFR reduction from baseline, estimated GFR less than 15 mL/min/1.73 m2, or dialysis or transplant). Pooled logistic models using inverse probability weighting estimated the hazard odds ratio (HOR) of the composite outcome associated with each BP category stratified by CKD diagnosis.

RESULTS

A total of 844 children (524 [62.1%] male; median age, 11 [interquartile range, 8-15] years; 151 [17.9%] black; 580 [68.7%] with nonglomerular CKD; and 264 [31.3%] with glomerular CKD) with complete baseline data and median follow-up of 4 (interquartile range, 2-6) years were included. One hundred ninety-six participants with nonglomerular diagnoses (33.8%) and 99 with glomerular diagnoses (37.5%) reached the composite outcome. Baseline systolic BP in at least the 90th percentile was associated with a higher risk of the composite outcome (HOR for nonglomerular disease, 1.58 [95% CI, 1.07-2.32]; HOR for glomerular disease, 2.85 [95% CI, 1.64-4.94]) compared with baseline systolic BP in less than the 50th percentile. Time-fixed estimates were substantially lower compared with time-varying systolic BP percentile categories (HOR among those with nonglomerular CKD, 3.75 [95% CI, 2.53-5.57]; HOR among those with glomerular diagnoses, 5.96 [95% CI, 3.37-10.54]) comparing those at or above the 90th percentile vs below the 50th percentile. Adjusted models (adjusted for proteinuria and use of antihypertensives) attenuated the risk in nonglomerular CKD (adjusted HOR for baseline measurement, 1.52 [95% CI, 0.98-2.36]; adjusted HOR for time-varying measurement, 2.25 [95% CI, 1.36-3.72]) and in glomerular CKD (adjusted HOR for baseline, 0.97 [95% CI, 0.39-2.36]; adjusted HOR for time-varying measurement, 1.41 [95% CI, 0.65-3.03]). Similar results were observed for diastolic BP.

CONCLUSIONS AND RELEVANCE

Among children with nonglomerular CKD included in this study, elevated time-varying BP measurements were associated with a greater risk of CKD progression compared with baseline BP measurement. This finding suggests that previous studies using only baseline BP likely underestimated the association between BP and CKD progression.

Association of Trimethylamine, Trimethylamine N-oxide, and Dimethylamine with Cardiovascular Risk in Children with Chronic Kidney Disease

Chronic kidney disease (CKD) is associated with high risk for cardiovascular disease (CVD). Gut microbiota-dependent metabolites trimethylamine (TMA), trimethylamine N-oxide (TMAO), and dimethylamine (DMA) have been linked to CKD and CVD. We examined whether these methylamines are correlated with cardiovascular risk in CKD children. A total of 115 children and adolescents with CKD stage G1-G4 were enrolled in this cross-sectional study. Children with CKD stage G2-G4 had higher plasma levels of DMA, TMA, and TMAO, but lower urinary levels of DMA and TMAO than those with CKD stage G1. Up to 53% of CKD children and adolescents had blood pressure (BP) abnormalities on 24-h ambulatory BP monitoring (ABPM). Plasma TMA and DMA levels inversely associated with high BP load as well as estimated glomerular filtration rate (eGFR). Additionally, CKD children with an abnormal ABPM profile had decreased abundance of phylum Cyanobacteria, genera Subdoligranulum, Faecalibacterium, Ruminococcus, and Akkermansia. TMA and DMA are superior to TMAO when related to high BP load and other CV risk factors in children and adolescents with early-stage CKD. Our findings highlight that gut microbiota-dependent methylamines are related to BP abnormalities and CV risk in pediatric CKD. Further studies should determine whether these microbial markers can identify children at risk for CKD progression.

Time to Initiation of Antihypertensive Therapy After Onset of Elevated Blood Pressure in Patients With Primary Proteinuric Kidney Disease

Rationale & Objective

The objective of the study was to estimate the prevalence of hypertension in patients with proteinuric kidney disease and evaluate blood pressure (BP) control.

Study Design

Retrospective cohort study.

Setting & Participants

Data from adults and children with proteinuric kidney disease enrolled in the multicenter Kidney Research Network Registry were used for this study.

Exposure

Proteinuric kidney disease.

Outcomes

Hypertension and BP control.

Analytical Approach

Patients with white-coat hypertension were excluded. Patients were censored at end-stage kidney disease onset. Patients were defined as hypertensive either by hypertension diagnosis code, having 2 or more encounters with elevated BPs, or treatment with antihypertensive therapy excluding renin-angiotensin-aldosterone system blockade. Elevated BP was defined as greater than 95th percentile for children and >140/90 mm Hg in adults. Sustained BP control was defined as 2 or more consecutive encounters with BPs lower than 95th percentile for children and <140/90 mm Hg for adults. Kaplan-Meier and Cox proportional hazards analyses were used to evaluate the time to initiation of antihypertensive therapy.

Results

842 patients, 69% adults and 31% children, with a total observation period of 6,722 patient-years were included in the analysis. 644 (76%) had hypertension during observation. There was no difference in the prevalence of hypertension between children and adults (74% vs 78%; P = 0.3). Hypertension was most common among those of African American race compared with other races (90% vs 72%-75%; P = 0.003). 504 (78%) patients with hypertension achieved BP control but only 51% achieved control within 1 year. 140 (22%) patients with hypertension never achieved BP control during a median of 41 (IQR, 24-73) months of observation.

Limitations

Differing BP control goals that may lead to overestimation of the controlled patient population.

Conclusions

Hypertension affects most patients with proteinuric kidney disease regardless of age. Time to BP control exceeded 1 year in 50% of patients with hypertension and 22% did not demonstrate control. This study highlights the need to address hypertension early and completely in disease management of patients with proteinuric kidney disease.

Incidence of Initial Renal Replacement Therapy Over the Course of Kidney Disease in Children

The Chronic Kidney Disease in Children Study, a prospective cohort study with data collected from 2003 to 2018, provided the first opportunity to characterize the incidence of renal replacement therapy (RRT) initiation over the life course of pediatric kidney diseases. In the current analysis, parametric generalized gamma models were fitted and extrapolated for RRT overall and by specific treatment modality (dialysis or preemptive kidney transplant). Children were stratified by type of diagnosis: nonglomerular (mostly congenital; n = 650), glomerular–hemolytic uremic syndrome (HUS; n = 49), or glomerular–non-HUS (heterogeneous childhood onset; n = 216). Estimated durations of time to RRT after disease onset for 99% of the nonglomerular and glomerular–non-HUS groups were 42.5 years (95% confidence interval (CI): 31.0, 54.1) and 25.4 years (95% CI: 14.9, 36.0), respectively. Since onset for the great majority of children in the nonglomerular group was congenital, disease duration equated with age. A simulation-based estimate of age at RRT for 99% of the glomerular population was 37.9 years (95% CI: 33.6, 63.2). These models performed well in cross-validation. Children with glomerular disease received dialysis earlier and were less likely to have a preemptive kidney transplant, while the timing and proportions of dialysis and transplantation were similar for the nonglomerular group. These diagnosis-specific estimates provide insight into patient-centered prognostic information and can assist in RRT planning efforts for children with moderate-to-severe kidney disease who are receiving regular specialty care.

Arterial Hypertension and Unusual Ascending Aortic Dilatation in a Neonate With Acute Kidney Injury: Mechanistic Computer Modeling

Background

Neonatal asphyxia caused kidney injury and severe hypertension in a newborn. An unusually dilatated ascending aorta developed. Dialysis and pharmacological treatment led to partial recovery of the ascending aortic diameters. It was hypothesized that the aortic dilatation may be associated with aortic stiffening, peripheral resistance, and cardiovascular changes. Mathematical modeling was used to better understand the potential causes of the hypertension, and to confirm our clinical treatment within the confines of the model's capabilities.

Methods

The patient's systolic arterial blood pressure showed hypertension. Echocardiographic exams showed ascending aorta dilatation during hypertension, which partially normalized upon antihypertensive treatment. To explore the underlying mechanisms of the aortic dilatation and hypertension, an existing lumped parameter hemodynamics model was deployed. Hypertension was simulated using realistic literature informed parameter values. It was also simulated using large parameter perturbations to demonstrate effects. Simulations were designed to permit examination of causal mechanisms. The hypertension inducing effects of aortic stiffnesses, vascular resistances, and cardiac hypertrophy on blood flow and pressure were simulated. Sensitivity analysis was used to stratify causes.

Results

In agreement with our clinical diagnosis, the model showed that an increase of aortic stiffness followed by augmentation of peripheral resistance are the prime causes of realistic hypertension. Increased left ventricular elastance may also cause hypertension. Ascending aortic pressure and flow increased in the simultaneous presence of left ventricle hypertrophy and augmented small vessel resistance, which indicate a plausible condition for ascending aorta dilatation. In case of realistic hypertension, sensitivity analysis showed that the treatment of both the large vessel stiffness and small vessel resistance are more important in comparison to cardiac hypertrophy.

Conclusion and Discussion

Large vessel stiffness was found to be the prime factor in arterial hypertension, which confirmed the clinical treatment. Treatment of cardiac hypertrophy appears to provide significant benefit but may be secondary to treatment of large vessel stiffness. The quantitative grading of pathophysiological mechanisms provided by the modeling may contribute to treatment recommendations. The model was limited due to a lack of data suitable to permit model identification.

Obstructive sleep apnea and hypertension in pediatric chronic kidney disease

BACKGROUND

Children with chronic kidney disease (CKD) are at risk for obstructive sleep apnea (OSA) and hypertension. The objectives of this study were to explore associations between OSA severity using the apnea-hypopnea-index(AHI) and obstructive apnea-hypopnea-index(OAHI) on polysomnography (PSG), OSA symptoms, and measures of hypertension in children with CKD.

METHODS

One-night in-laboratory PSGs and 24-h ambulatory blood pressure monitoring (ABPM) were performed on children with CKD stages 2-5 (non-dialysis dependent). Sleep questionnaires, including the modified Epworth Sleepiness Scale (ESS) and the Pediatric Sleep Questionnaire (PSQ), were administered during the sleep study.

RESULTS

Nineteen children and adolescents completed a PSG and questionnaires and thirteen completed ABPMs. Mean (standard deviation) age at the time of the sleep study was 14.1 (3.2) years. Eleven (58%) participants had CKD stage two, and eight (42%) had stage 3-4. None of the participants were found to have OSA on PSG. One participant had a positive ESS score (≥ 11) and five participants had positive PSQ scores (≥  eight). Night systolic and diastolic pressures were strongly correlated with the OAHI (r = 0.67 and r = 0.69, respectively, p < 0.05), while the AHI was not correlated with any blood pressure measures.

CONCLUSIONS

Our study did not find OSA on PSG in children with predominantly mild to moderate CKD. The OAHI was found to be strongly correlated with nighttime blood pressures. Future prospective studies with a larger sample size are needed to monitor for potential progression of symptoms and findings on PSG in pediatric patients as they evolve across the spectrum of CKD.

Evaluation of carotid intima-media thickness and factors associated with cardiovascular disease in children and adolescents with chronic kidney disease

OBJECTIVE

To assess the carotid intima-media thickness and factors associated with cardiovascular disease in children and adolescents with chronic kidney disease.

MATERIAL AND METHODS

Observational, cross-sectional study carried out at the Universidade Federal de São Paulo (chronic kidney disease outpatient clinics) with 55 patients (60% males) with a median age of 11.9 years (I25-I75: 9.2-14.8 years). Of the 55 patients, 43 were on conservative treatment and 12 were on dialysis. Serum laboratory parameters (creatinine, uric acid, C-reactive protein, total cholesterol and fractions, and triglycerides), nutritional status (z-score of body mass index, z-score of height/age), body fat (fat percentage and waist circumference), and blood pressure levels were evaluated. The carotid intima-media thickness measure was evaluated by a single ultrasonographer and compared with percentiles established according to gender and height. Data collection was performed between May 2015 and March 2016.

RESULTS

Of the children and adolescents with chronic kidney disease, 74.5% (95% CI: 61.0; 85.3) showed an increase (>P95) in carotid intima-media thickness. In patients with stages I and II hypertension, 90.9% had increased carotid intima-media thickness. Nutritional status, body fat and laboratory tests were not associated with increased carotid intima-media thickness. After multivariate adjustment, only puberty (PR=1.30, p=0.037) and stages I and II arterial hypertension (PR=1.42, p=0.011) were independently associated with carotid intima-media thickness alterations.

CONCLUSION

The prevalence of increased carotid thickness was high in children and adolescents with chronic kidney disease. Puberty and arterial hypertension were independently associated with increased carotid intima-media thickness.

Blood Pressure Abnormalities Associated with Gut Microbiota-Derived Short Chain Fatty Acids in Children with Congenital Anomalies of the Kidney and Urinary Tract

Both kidney disease and hypertension can originate from early life. Congenital anomalies of the kidney and urinary tract (CAKUT) are the leading cause of chronic kidney disease (CKD) in children. Since gut microbiota and their metabolite short chain fatty acids (SCFAs) have been linked to CKD and hypertension, we examined whether gut microbial composition and SCFAs are correlated with blood pressure (BP) load and renal outcome in CKD children with CAKUT. We enrolled 78 children with CKD stage G1-G4. Up to 65% of children with CAKUT had BP abnormalities on 24 h ambulatory blood pressure monitoring (ABPM). CKD children with CAKUT had lower risk of developing BP abnormalities and CKD progression than those with non-CAKUT. Reduced plasma level of propionate was found in children with CAKUT, which was related to increased abundance of phylum Verrucomicrobia, genus Akkermansia, and species Bifidobacterium bifidum. CKD children with abnormal ABPM profile had higher plasma levels of propionate and butyrate. Our findings highlight that gut microbiota-derived SCFAs like propionate and butyrate are related to BP abnormalities in children with an early stage of CKD. Early assessments of these microbial markers may aid in developing potential targets for early life intervention for lifelong hypertension prevention in childhood CKD.

Fibroblast growth factor 23 and tubular sodium handling in young patients with incipient chronic kidney disease

Background

Experimental studies have shown fibroblast growth factor 23 (FGF23)-mediated upregulation of the distal tubule sodium/chloride (Na+Cl−) co-transporter leading to increased Na reabsorption, volume expansion and hypertension. However, data on the associations of FGF23 with renal Na regulation and blood pressure (BP) are lacking in young CKD patients.

Methods

FGF23 and other determinants of mineral metabolism, plasma renin activity (PRA), fractional excretion of Na (FENa) and BP, were analyzed at a single center in 60 patients aged 5–22 years with CKD Stages 1 (n = 33) and Stages 2–3 (n = 27) defined by cystatin C- and creatinine-based estimating equations (estimated glomerular filtration rate, eGFR). Associations between FGF23 and renal Na handling were explored by regression analysis.

Results

Median FGF23 levels were higher in CKD Stages 2–3 versus CKD 1 (119 versus 79 RU/mL; P < 0.05), with hyperparathyroidism [parathyroid hormone (PTH) >69 pg/mL] in only few subjects with CKD Stages 2–3. Median FENa was comparable in both subgroups, but with proportionally more values above the reference mean (0.55%) in CKD Stages 2–3 and 3-fold higher (1.6%) in CKD Stage 3. PRA was higher in CKD Stages 2–3 (P < 0.05). Meanwhile in CKD Stage 1, FGF23 did not associate with FENa, and in CKD Stages 2–3 FGF23 associated positively with FENa (r = 0.4; P < 0.05) and PTH (r = 0.45; P < 0.05), and FENa associated with FE of phosphate (r = 0.6; P < 0.005). Neither FGF23 nor FENa was associated with systolic or diastolic BP in either subgroup. The negative association of eGFR by cystatin with FENa remained the strongest predictor of FENa by multivariable linear regression in CKD Stages 2–3.

Conclusions

The elevated FGF23, FENa and PRA and the positive association of FGF23 with FENa do not suggest FGF23-mediated increased tubular Na reabsorption and volume expansion as causing hypertension in young patients with incipient CKD.

Academic achievement in children with chronic kidney disease: a report from the CKiD cohort

BACKGROUND

There are limited data to describe academic achievement outcomes for children with mild to moderate pediatric chronic kidney disease (CKD). The objective of this study was to describe the prevalence of low academic achievement in patients with mild to moderate CKD.

METHODS

Wechsler Individual Achievement Test, Second Edition, Abbreviated (WIAT-II-A) data were collected at entry into the Chronic Kidney Disease in Children (CKiD) study. Achievement in basic reading, spelling, mathematics, and total achievement was evaluated with a focus on the effects of comorbid CKD-related variables, neurocognitive, and school-based characteristics on academic achievement.

RESULTS

WIAT-II-A data were available for 319 children in the CKiD cohort. Low total academic achievement was present in 34% percent of the sample. There was no significant effect of CKD-related medical variables on academic achievement. Mathematics had the lowest distribution of achievement scores. In univariate models, low achievement was significantly related to days of missed school (p = 0.006) and presence of individualized education plan (p < 0.0001).

CONCLUSIONS

Low academic achievement was seen in over one-third of children with CKD, with the most difficulty observed in the domain of mathematics. Providers and educators should monitor for academic difficulties in this population in order to facilitate early educational assistance and promote positive educational outcomes.

Comparison of echocardiographic changes in children with primary hypertension and hypertension due to mild to moderate chronic kidney disease

BACKGROUND

Chronic systemic hypertension has a well-known association with increased cardiovascular morbidity and mortality. One of the most important target organs affected in systemic hypertension is the heart. In addition, chronic kidney disease (CKD) further increases the mortality from cardiovascular disease. The aim of this study was to evaluate the differences in the cardiovascular changes in pediatric patients with primary hypertension (pHTN) vs. those with secondary hypertension from chronic kidney disease (CKD-HTN).

METHODS

This was a retrospective chart review of patients with CKD-HTN and pHTN. The medical records were reviewed for anthropometric data, biochemical assessment of renal function, and for cardiovascular changes on echocardiogram.

RESULTS

Twenty-three patients with pHTN and 29 patients with CKD-HTN were included in the study. There were no differences in age, gender, weight, height, body mass index, and blood pressure between the 2 groups. There was a high prevalence of left ventricular diastolic dysfunction among both the groups (CKD-HTN 25 vs. pHTN 26%). Reduced mitral valve inflow Doppler E/A ratio, a marker of left ventricular diastolic dysfunction in echocardiogram, was more pronounced in CKD-HTN patents, in comparison to those with pHTN (p = 0.042). Also, diastolic function worsened with declining glomerular filtration rate in patients with CKD-HTN. Similarly, patients with CKD-HTN had a larger aortic root dimension when compared to patients with pHTN (p = 0.049).

CONCLUSIONS

The prevalence of left ventricular diastolic dysfunction is similar in patients with pHTN and CKD-HTN. Patients with CKD-HTN appear to have more severe diastolic dysfunction and larger aortic root dimensions.

Adherence to long-term use of renin-angiotensin II-aldosterone system inhibitors in children with chronic kidney disease

BACKGROUND

Although renin-angiotensin II-aldosterone system inhibitor (RASI) use for renal protection is well-documented, adherence to RASI therapy in the pediatric population is unclear. This study aimed to evaluate patient characteristics associated with adherence to chronic RASI use in patients with childhood chronic kidney disease (CKD).

METHODS

Childhood CKD was identified using ICD-9 codes in the population-based, Taiwan national health insurance research database between 1997 and 2011. Patients continuously receiving RASIs for ≥3 months without interruption > 30 days after CKD diagnosis were defined as incident users. Medication adherence was measured as the proportion of days covered (PDC) by RASI prescription refills during the study period. Multivariate logistic regression was employed to assess the odds for adherence (PDC ≥80%) to RASI refills.

RESULTS

Of 1271 incident users of RASI chronic therapy, 16.9% (n = 215) had PDC ≥80%. Compared to the group with PDC < 80%, patients in the high adherence group more often had proteinuria (aOR [adjusted odds ratio]1.93; 95%CI [confidence interval], 1.18-3.17), anemia (aOR, 1.76; 95% CI, 1.20-2.58), and time to start of chronic use > 2 years (aOR, 1.12; 95%CI, 1.06-1.19). Odds of being non-adherent were increased by hypertension and older ages (comparing to < 4 years) at start of chronic use, 9-12 years (aOR, 0.38; 95%CI, 0.17-0.82), 13-17 years (aOR, 0.45; 95%CI, 0.22-0.93),≥18 years (aOR, 0.34; 95%CI 0.16-0.72) and males (aOR, 0.68; 95%CI, 0.49-0.94).

CONCLUSIONS

The rate of RASI prescription refilling adherence was relatively low and associated with CKD-specific comorbid conditions. This study identifies factors associated with low adherence and highlights the need to identify those who should be targeted for intervention to achieve better blood pressure control, preventing CKD progression.

Management of Hypertension in CAKUT: Protective Factor for CKD

Patients with congenital kidney and urinary tract abnormalities (CAKUT) will often develop end-stage renal disease at some point and the need for renal replacement therapy is associated with high rates of morbidity and mortality. Hence, efforts to slow the progression of the disease are essential. Hypertension has been proven to be an independent risk factor for faster decline of glomerular filtration rate in renal patients, but studies involving only children with CAKUT are scarce. We performed a literature review to explore the association of hypertension with faster chronic kidney disease progression in children with CAKUT and also treatment options in this condition. A recent study reported an annual decline in GFR of 1.8 ml/min/1.73 m² among hypertensive patients with non-glomerular CKD, compared with 0.8 ml/min/1.73 m² in normotensive children. A multicenter prospective cohort in Brazil showed that a 1-unit increase in systolic blood pressure Z-score was associated with a 1.5-fold higher risk of disease progression. Since renin-angiotensin-aldosterone system activation is the most important mechanism of hypertension in these children, the first-line therapy involves the use of inhibitors of this axis, including angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers type I, which also promote an anti-fibrotic effect. Recent studies have shown a good safety profile for use in patients with chronic kidney disease and also in those with solitary kidneys. Hypertension is an independent risk factor for kidney disease progression and should be promptly managed for renal protection, especially among patients with CAKUT, the primary cause of chronic kidney disease in the pediatric population.

Hypertension in Childhood Nephrotic Syndrome

Arterial hypertension (HTN) is commonly encountered by clinicians treating children with steroid sensitive (SSNS) and steroid resistant nephrotic syndrome (SRNS). Although the prevalence of HTN in SSNS is less documented than in SRNS, recent studies reported high prevalence in both. Studies have estimated the prevalence of HTN in different patient populations with NS to range from 8 to 59.1%. Ambulatory HTN, abnormalities in BP circadian rhythm, and measures of BP variability are prevalent in patients with NS. Multiple mechanisms and co-morbidities contribute to the pathophysiology of HTN in children with NS. Some contributing factors are known to cause acute and episodic elevations in blood pressure such as fluid shifts, sodium retention, and medication side effects (steroids, CNIs). Others are associated with chronic and more sustained HTN such as renal fibrosis, decreased GFR, and progression of chronic kidney disease. Children with NS are more likely to suffer from other cardiovascular disease risk factors, such as obesity, increased measures of arterial stiffness [increased carotid intima-media thickness (cIMT), endothelial dysfunction, increased pulse wave velocity (PWV)], impaired glucose metabolism, dyslipidemia, left ventricular hypertrophy (LVH), left ventricular dysfunction, and atherosclerosis. Those risk factors have been associated with premature death in adults. In this review on HTN in patients with NS, we will discuss the epidemiology and pathophysiology of hypertension in patients with NS, as well as management aspects of HTN in children with NS.

Long-term safety and tolerability of valsartan in children aged 6 to 17 years with hypertension

OBJECTIVE

The present study aimed to assess the long-term safety and tolerability of valsartan in hypertensive children aged 6-17 years, with or without chronic kidney disease (CKD).

METHODS

This was an 18-month, open-label, multicentre, prospective study conducted in 150 patients with history of hypertension with or without CKD. The primary endpoint was long-term safety and tolerability of valsartan and valsartan-based treatments, assessed in terms of adverse events (AEs), serious AEs, laboratory measurements, estimated glomerular filtration rate (eGFR), urinalysis and electrocardiogram.

RESULTS

Of 150 enrolled patients, 117 (78%) completed the study. At week 78, a clinically and statistically significant reduction in mean sitting systolic and diastolic blood pressures was observed in all patients (- 14.9 mmHg and - 10.6 mmHg, respectively). Within the first 3 months of treatment, mean urine albumin creatinine ratio decreased in CKD population, which was sustained. A higher percentage of CKD patients had at least one AE compared to non-CKD patients (85.3% vs. 73.3%, respectively). The majority of AEs were mild (50.7%) or moderate (18.7%) in severity. As expected, in patients with underlying CKD, increases in serum potassium, creatinine and blood urea nitrogen were more commonly reported compared to non-CKD patients. A > 25% decrease in Schwartz eGFR was observed in 28.4% of CKD patients and 13.5% of non-CKD patients.

CONCLUSIONS

Valsartan was generally well tolerated, with an AE profile consistent with angiotensin receptor blockers in the overall population and in patients with underlying CKD. Long-term efficacy was maintained and a beneficial effect on proteinuria was observed.

Mortality Risks among Various Primary Renal Diseases in Children and Adolescents on Chronic Dialysis

There is little information available on the association between primary renal disease (PRD) and long-term mortality in the pediatric dialysis population. The objective of this study was to explore mortality risks in children and adolescents on chronic dialysis, specifically focused on the risk of various PRDs. The study cohort included children and adolescents with end-stage renal disease (ESRD) (aged < 20 years) who had received dialysis for at least 90 days between 2000 and 2014 and were identified from Taiwan's National Health Insurance medical claims. A total of 530 children and adolescents were included in the study. The median age of the included patients was 13.6 years and 305 (57.5%) patients were males. One hundred and seven patients died during the follow-up period and the median survival time was 6.0 years. Mortality was highest in the youngest patients. For patients with the following PRDs, mortality was significantly higher than that in patients with primary glomerulonephritis: secondary glomerulonephritis (adjusted hazard ratio (aHR): 2.50; 95% confidence interval (CI): 1.03⁻6.08), urologic disorder (aHR: 4.77; 95% CI: 1.69⁻13.46), and metabolic diseases (aHR: 5.57; 95% CI: 1.84⁻16.85). Several kinds of PRDs appear to have high mortality risks in the pediatric dialysis population. These differences in mortality risk highlight the importance of the focused clinical management of these high-risk subgroups.

Diagnosis, Evaluation, and Management of High Blood Pressure in Children and Adolescents

Systemic hypertension is a major cause of morbidity and mortality in adulthood. High blood pressure (HBP) and repeated measures of HBP, hypertension (HTN), begin in youth. Knowledge of how best to diagnose, manage, and treat systemic HTN in children and adolescents is important for primary and subspecialty care providers.

OBJECTIVES

To provide a technical summary of the methodology used to generate the 2017 "Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents," an update to the 2004 "Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents."

DATA SOURCES

Medline, Cochrane Central Register of Controlled Trials, and Excerpta Medica Database references published between January 2003 and July 2015 followed by an additional search between August 2015 and July 2016.

STUDY SELECTION

English-language observational studies and randomized trials.

METHODS

Key action statements (KASs) and additional recommendations regarding the diagnosis, management, and treatment of HBP in youth were the product of a detailed systematic review of the literature. A content outline establishing the breadth and depth was followed by the generation of 4 patient, intervention, comparison, outcome, time questions. Key questions addressed: (1) diagnosis of systemic HTN, (2) recommended work-up of systemic HTN, (3) optimal blood pressure (BP) goals, and (4) impact of high BP on indirect markers of cardiovascular disease in youth. Once selected, references were subjected to a 2-person review of the abstract and title followed by a separate 2-person full-text review. Full citation information, population data, findings, benefits and harms of the findings, as well as other key reference information were archived. Selected primary references were then used for KAS generation. Level of evidence (LOE) scoring was assigned for each reference and then in aggregate. Appropriate language was used to generate each KAS based on the LOE and the balance of benefit versus harm of the findings. Topics that could not be researched via the stated approach were (1) definition of HTN in youth, and (2) definition of left ventricular hypertrophy. KASs related to these stated topics were generated via expert opinion.

RESULTS

Nearly 15 000 references were identified during an initial literature search. After a deduplication process, 14 382 references were available for title and abstract review, and 1379 underwent full text review. One hundred twenty-four experimental and observational studies published between 2003 and 2016 were selected as primary references for KAS generation, followed by an additional 269 primary references selected between August 2015 and July 2016. The LOE for the majority of references was C. In total, 30 KASs and 27 additional recommendations were generated; 12 were related to the diagnosis of HTN, 13 were related to management and additional diagnostic testing, 3 to treatment goals, and 2 to treatment options. Finally, special additions to the clinical practice guideline included creation of new BP tables based on BP values obtained solely from children with normal weight, creation of a simplified table to enhance screening and recognition of abnormal BP, and a revision of the criteria for diagnosing left ventricular hypertrophy.

CONCLUSIONS

An extensive and detailed systematic approach was used to generate evidence-based guidelines for the diagnosis, management, and treatment of youth with systemic HTN.

Time-varying coefficient of determination to quantify the explanatory power of biomarkers on longitudinal GFR among children with chronic kidney disease

PURPOSE

Coefficients of determination (R²) for continuous longitudinal data are typically reported as time constant, if they are reported at all. The widely used mixed model with random intercepts and slopes yields the total outcome variance as a time-varying function. We propose a generalized and intuitive approach based on this variance function to estimate the time-varying predictive power (R²) of a variable on outcome levels and changes.

METHODS

Using longitudinal estimated glomerular filtration rate (eGFR) from the Chronic Kidney Disease in Children Study, linear mixed models characterized the R² for two chronic kidney disease (CKD) risk factors measured at baseline: a traditional marker (proteinuria) and a novel marker (fibroblast growth factor 23 [FGF23]).

RESULTS

Time-varying R² divulged different disease processes by risk factor and diagnoses. Among children with glomerular CKD, time-varying R² for proteinuria had significant upward trends, suggesting increasing power to predict eGFR change, but crossed with FGF23, which was higher up to 2.5 years from baseline. In contrast, among those with nonglomerular CKD, proteinuria explained more than FGF23 at all times, and time-varying R² for each risk factor was not substantially different from time-constant estimates.

CONCLUSIONS

Proteinuria and FGF23 explained substantial eGFR variability over time. Time-varying R² can characterize predictive roles of risk factors on disease progression, overcome limitations of time-constant estimates, and are easily derived from mixed effects models.

Hypertension in Pediatric Dialysis Patients: Etiology, Evaluation, and Management

PURPOSE OF REVIEW

Review epidemiology, pathophysiology, and management of hypertension in the pediatric dialysis population.

RECENT FINDINGS

Interdialytic blood pressure measurement, especially with ambulatory blood pressure monitoring, is the gold standard to assess for hypertension. Tools to assess dry weight aid in achievement of euvolemia, the primary therapy for management of hypertension. Persistent hypertension should be treated with antihypertensive medications and potentially with native nephrectomies. Cardiovascular disease continues to be the primary cause of morbidity and mortality in the dialysis population with hypertension as an important modifiable factor. Achievement on dry weight and limiting both aggressiveness of interdialytic weight gain and ultrafiltration rate underlie the best approach. Tools to assess volume status beyond clinical assessment have shown promise in achieving euvolemia. When hypertension persists despite achievement of euvolemia, antihypertensive medications may be required and in some cases native nephrectomies. Future studies in children are needed to determine the best antihypertensive class and ideal rate of ultrafiltration on hemodialysis towards achievement of normotension and reduction of cardiovascular risk.

Factors associated with reduction of left ventricular mass in children on peritoneal dialysis

AIM

This study aimed to investigate sensitive factors involved in left ventricular mass reduction in children with end-stage renal disease (ESRD) undergoing peritoneal dialysis.

METHODS

Thirty-five subjects on peritoneal dialysis were enrolled. Two successive echocardiographic and clinical data for each subject were obtained. Blood pressure and left ventricular mass index (LVMI) were indexed through a division with the normal 95^th percentile value. Differences in numeric data between two datasets were calculated.

RESULTS

The mean age was 12.9 ± 4.6 years. Predictors of left ventricular hypertrophy and its persistence were systolic blood pressure index (P = 0.019 and P = 0.046) and E' velocity (P = 0.035 and P = 0.031) in univariate analysis. However, differences in these predictors between the datasets were not related to the change in indexed LVMI. Reduction in indexed LVMI was correlated to a reduction of indexed left atrial volume (R = 0.638, P = 0.001), trans-mitral A velocity (R = 0.443, P = 0.011), and serum blood urea nitrogen level (R = 0.372, P = 0.028) and an elevation of haemoglobin level (R = -0.374, P = 0.027).

CONCLUSION

The extent of circulating volume expansion is potentially the main predictive factor for change of LVMI, because the volume dependent diastolic functional variables correlate to the change of LVMI. Further study with a large number of ESRD children including a group under fluid volume control is needed to investigate the role of volume expansion on the change of LVMI.

Twenty-Four-Hour Ambulatory Blood Pressure versus Clinic Blood Pressure Measurements and Risk of Adverse Outcomes in Children with CKD

BACKGROUND

and objectives Our objective was to determine whether clinic BPs (taken at either a single visit or two sequential visits) are inferior to ambulatory BPs in their ability to discriminate risk of adverse outcomes in children with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We included 513 participants of the CKD in Children Study who had clinic BPs and 24-hour ambulatory BP monitoring performed during similar timeframes. Predictors of interest were systolic BPs taken at a single visit or two repeated visits within a 1-year period compared with mean wake and sleep systolic ambulatory BPs. Outcomes were left ventricular hypertrophy and ESKD. We determined the ability for each BP parameter to provide risk discrimination using c statistics.

RESULTS

During mean follow-up of 3.5 years, 123 participants developed ESKD. In cross-sectional unadjusted analysis, every 0.1 increase in systolic BP index was associated with a 2.0 times higher odds of left ventricular hypertrophy (95% confidence interval, 1.5 to 2.8) by clinic BPs versus 1.8 times higher odds (95% confidence interval, 1.3 to 2.4) by ambulatory wake BP. The c statistic was highest for clinic BP (c=0.65; 95% confidence interval, 0.58 to 0.73) but similar to ambulatory wake BP (c=0.64; 95% confidence interval, 0.57 to 0.71) for the discrimination of left ventricular hypertrophy. In longitudinal unadjusted analysis, every 0.1 increase in systolic BP index was associated with a higher risk of ESKD using repeated clinic (hazard ratio, 1.5; 95% confidence interval, 1.3 to 1.8) versus ambulatory wake BP (hazard ratio, 1.6; 95% confidence interval, 1.3 to 2.0). Unadjusted c statistics were the same for wake (c=0.61; 95% confidence interval, 0.56 to 0.67) and clinic systolic BPs (c=0.61; 95% confidence interval, 0.55 to 0.66) for discriminating risk of ESKD.

CONCLUSIONS

Clinic BPs taken in a protocol-driven setting are not consistently inferior to ambulatory BP in the discrimination of BP-related adverse outcomes in children with CKD.

Is Blood Pressure Improving in Children With Chronic Kidney Disease? A Period Analysis

Uncontrolled hypertension in children with chronic kidney disease (CKD) has been identified as one of the main factors contributing to progression of CKD and increased risk for cardiovascular disease. Recent efforts to achieve better blood pressure (BP) control have been recommended. The primary objective of this analysis was to compare BP control over 2 time periods among participants enrolled in the CKiD study (Chronic Kidney Disease in Children). Casual BP and 24-hour ambulatory BP monitor data were compared among 851 participants during 2 time periods: January 1, 2005, through July 1, 2008 (period 1, n=345), and July 1, 2010, through December 31, 2013 (period 2, n=506). Multivariable logistic regression to model the propensity of a visit record being in period 2 as a function of specific predictors was performed. After controlling for confounding variables (age, sex, race, socioeconomics, CKD duration, glomerular filtration rate, proteinuria, body mass index, growth failure, and antihypertensives), no significant differences were detected between time periods with respect to casual BP status (prehypertension: 15% versus 15%; uncontrolled hypertension: 18% versus 17%; P=0.87). Analysis of ambulatory BP monitor data demonstrated higher ambulatory BP indices, most notably masked hypertension in period 2 (36% versus 49%; P<0.001). Average sleep BP index (P<0.05) and sleep BP loads (P<0.05) were higher in period 2. Despite publication of hypertension recommendations and guidelines for BP control in patients with CKD, this study suggests that hypertension remains undertreated and under-recognized in children with CKD. This analysis also underscores the importance of routine ambulatory BP monitor assessment in children with CKD.

Clinical Indices Can Standardize and Monitor Pediatric Care: A Novel Mechanism to Improve Quality and Safety

OBJECTIVE

The Cancer Care Index (CCI), a single metric that sums the number of undesirable patient events in a given time frame (either preventable harm events or missed opportunities to provide optimal care), resulted in a 42% improvement in performance. Our objective was to test the index concept in other service lines to determine whether similar performance improvement occurred.

STUDY DESIGN

Care indices were developed and introduced in 3 additional service lines: Nephrology (Chronic Kidney Disease Care Index; CKDCI), Pulmonology (Lung Transplantation Care Index; LTCI), and Otolaryngology (Tracheostomy Care Index; TCI). After reaching agreement on specific harms to be avoided and elements of optimal care that should be reliably delivered, these items were compiled into indices that were updated monthly. Reports included each element individually and the total for all elements. Baseline performance was calculated retrospectively for the previous year.

RESULTS

Significant improvement in performance occurred in each program following implementation of the clinical indices. The CKDCI was decreased by 63.2% (P < .001), the LTCI was decreased by 89.5% (P < .001), and the TCI was decreased by 53.0% (P < .001). Surveyed staff indicated satisfaction with use of the metric.

CONCLUSIONS

Clinical indices are useful for evaluating and managing the overall reliability of a program's ability to deliver optimal care, and are associated with improved clinical performance and satisfaction by service line staff when incorporated into a program's operation.