Cardiovascular risk assessment in children with chronic kidney disease

Pregnancy Zone Protein as an Emerging Biomarker for Cardiovascular Risk in Pediatric Chronic Kidney Disease

Cardiovascular disease (CVD) is a significant cause of mortality and morbidity among children with chronic kidney disease (CKD). The causes of pediatric CKD differ from those in adults, as congenital anomalies in the kidney and urinary tract (CAKUT) are the leading causes in childhood. Identifying ideal markers of CVD risk early is crucial for CKD children to improve their care. Previously, we screened differentially expressed proteins in CKD children with or without blood pressure (BP) abnormalities and identified pregnancy zone protein (PZP). In 106 children and adolescents with CKD stages G1-G4, we analyzed plasma PZP concentration. The associations between PZP and ambulatory BP monitoring (ABPM) profile, parameters of cardiac and carotid ultrasounds, indices of arterial stiffness, and nitric oxide (NO) parameters were determined. We observed that PZP positively correlated with arterial stiffness indices, beta index, and pulse wave velocity in CAKUT. CKD children with abnormalities in ABPM and night dipping displayed a higher PZP concentration than those without. Additionally, the PZP level was positively correlated with NO bioavailability. In conclusion, our results suggest PZP has differential influences on cardiovascular risk in CAKUT and non-CAKUT children. Identification of this relationship is novel in the pediatric CKD literature.

Get to the heart of pediatric kidney transplant recipients: Evaluation of left- and right ventricular mechanics by three-dimensional echocardiography

Background

Kidney transplantation (KTX) markedly improves prognosis in pediatric patients with end-stage kidney failure. Still, these patients have an increased risk of developing cardiovascular disease due to multiple risk factors. Three-dimensional (3D) echocardiography allows detailed assessment of the heart and may unveil distinct functional and morphological changes in this patient population that would be undetectable by conventional methods. Accordingly, our aim was to examine left- (LV) and right ventricular (RV) morphology and mechanics in pediatric KTX patients using 3D echocardiography.

Materials and methods

Pediatric KTX recipients (n = 74) with median age 20 (14–26) years at study enrollment (43% female), were compared to 74 age and gender-matched controls. Detailed patient history was obtained. After conventional echocardiographic protocol, 3D loops were acquired and measured using commercially available software and the ReVISION Method. We measured LV and RV end-diastolic volumes indexed to body surface area (EDVi), ejection fraction (EF), and 3D LV and RV global longitudinal (GLS) and circumferential strains (GCS).

Results

Both LVEDVi (67 ± 17 vs. 61 ± 9 ml/m2; p < 0.01) and RVEDVi (68 ± 18 vs. 61 ± 11 ml/m2; p < 0.01) were significantly higher in KTX patients. LVEF was comparable between the two groups (60 ± 6 vs. 61 ± 4%; p = NS), however, LVGLS was significantly lower (−20.5 ± 3.0 vs. −22.0 ± 1.7%; p < 0.001), while LVGCS did not differ (−29.7 ± 4.3 vs. −28.6 ± 10.0%; p = NS). RVEF (59 ± 6 vs. 61 ± 4%; p < 0.05) and RVGLS (−22.8 ± 3.7 vs. −24.1 ± 3.3%; p < 0.05) were significantly lower, however, RVGCS was comparable between the two groups (−23.7 ± 4.5 vs. −24.8 ± 4.4%; p = NS). In patients requiring dialysis prior to KTX (n = 64, 86%) RVGCS showed correlation with the length of dialysis (r = 0.32, p < 0.05).

Conclusion

Pediatric KTX patients demonstrate changes in both LV and RV morphology and mechanics. Moreover, the length of dialysis correlated with the contraction pattern of the right ventricle.

Molecular Mechanisms of Vascular Health: Insights From Vascular Aging and Calcification

Cardiovascular disease is the most common cause of death worldwide, especially beyond the age of 65 years, with the vast majority of morbidity and mortality due to myocardial infarction and stroke. Vascular pathology stems from a combination of genetic risk, environmental factors, and the biologic changes associated with aging. The pathogenesis underlying the development of vascular aging, and vascular calcification with aging, in particular, is still not fully understood. Accumulating data suggests that genetic risk, likely compounded by epigenetic modifications, environmental factors, including diabetes and chronic kidney disease, and the plasticity of vascular smooth muscle cells to acquire an osteogenic phenotype are major determinants of age-associated vascular calcification. Understanding the molecular mechanisms underlying genetic and modifiable risk factors in regulating age-associated vascular pathology may inspire strategies to promote healthy vascular aging. This article summarizes current knowledge of concepts and mechanisms of age-associated vascular disease, with an emphasis on vascular calcification.

Cardiovascular Risks of Hypertension: Lessons from Children with Chronic Kidney Disease

Hypertension is the most common complication of chronic kidney disease (CKD) in children, having a strong association with subsequential cardiovascular disease (CVD). In pediatric CKD, a considerable percentage of children with hypertension are undiagnosed or undertreated. Prior research has evaluated structural and functional markers of subclinical CVD and biomarkers in adults with CKD, while ideal biomarkers in pediatrics are still insufficiently studied. The ultimate goal of this review is to summarize what is currently known about state of hypertension, cardiovascular risk factors, and potential CVD markers/biomarkers in children with pre-dialysis CKD. We discuss omics-related biomarkers and the pathophysiologic processes of endothelial dysfunction, kidney injury, oxidative stress and inflammation that are classified by specific biomarkers. Moreover, we illustrate the existing challenges and highlight the paucity of pediatric CKD research to evaluate these CVD biomarkers for future clinical pediatric practice. Thus, achieving clinical utility of CVD biomarkers for use in pediatric CKD remains a significant challenge requiring additional efforts.

Reduced Blood Pressure Dipping Is A Risk Factor for the Progression of Chronic Kidney Disease in Children

Background: Elevated blood pressure and proteinuria are well-established risk factors for chronic kidney disease (CKD) progression in children. This study aimed to analyze risk factors for CKD progress, emphasizing detailed ambulatory blood pressure (ABPM) data. Methods: In 55 children with CKD II−V, observed for ≥1 year or until initiation of kidney replacement therapy, we analyzed ABPM, clinical, and biochemical parameters. Results: At the beginning, the glomerular filtration rate (eGFR) was 66 (interquartile range—IQR: 42.8−75.3) mL/min/1.73 m2, and the observation period was 27 (16−36) months. The mean eGFR decline was 2.9 ± 5.7 mL/min/1.73 m2/year. eGFR decline correlated (p < 0.05) with age (r = 0.30), initial proteinuria (r = 0.31), nighttime systolic and mean blood pressure (r = 0.27, r = 0.29), and systolic and diastolic blood pressure dipping (r = −0.37, r = −0.29). There was no relation between mean arterial pressure during 24 h (MAP 24 h Z-score) and eGFR decline and no difference in eGFR decline between those with MAP 24 h < and ≥50 th percentile. In multivariate analysis, systolic blood pressure dipping (beta = −0.43), presence of proteinuria (beta = −0.35), and age (beta = 0.25) were predictors of eGFR decline. Conclusions: Systolic blood pressure dipping may be a valuable indicator of CKD progression in children.

Low-density lipoprotein and blood pressure are important risk factors for vasculopathy in children on dialysis: a single center study

INTRODUCTION

We searched for risk factors of cardiovascular assessment among children on dialysis.

METHODS

This is a cross-sectional study of cardiovascular assessment of all patients on dialysis at xxx University Children's Hospital. Pediatric patients between the ages of 6 and 21 who were on hemodialysis and peritoneal dialysis treatment were included in the study. Cardiovascular evaluation included left ventricular mass index (LVMI), pulse wave velocity (PWV), and carotid intima-media thickness (cIMT) measurements.

RESULTS

Nineteen patients were included in this study. The LDL had a correlation with the cIMT z-score, but not to PWVz-score. Binary Logistic regression analysis found that only LDL was significantly associated to increased cIMT.

CONCLUSION

This study reports an association between high LDL and high blood pressure increased cIMT on dialyzed children. Strategies to reduce LDL and blood pressure in dialysis patients may prevent vasculopathy and long-term cardiovascular complications.

Evaluation of cardiovascular risk in children with solitary functioning kidney

BACKGROUND

The present study investigates cardiovascular risk and kidney damage in patients with solitary kidneys.

METHODS

Included in the study were 40 children with a unilateral functioning kidney and 60 healthy controls, all of whom were evaluated for carotid intima-media thickness, ischemia-modified albumin and oxidative stress parameters, and 24-h ambulatory blood pressure monitoring.

RESULTS

Serum creatinine and urine microalbumin levels were higher and creatinine clearance was lower in the patient group than in the control group, and serum ischemia-modified albumin, carotid intima-media thickness, aldosterone, plasma renin activity and blood pressure were all higher in the patient group than in the control group. In addition, the patient group was showed a non-dipper pattern.

CONCLUSION

Children with a normal functioning solitary kidney are likely at higher risk of developing cardiovascular disease and such patients should be followed closely before marked kidney impairment occurs.

Subclinical cardiac dysfunction in pediatric kidney transplant recipients identified by speckle-tracking echocardiography

BACKGROUND

Kidney transplantation (KTx) improves prognosis in children with kidney failure; still, these patients are prone to cardiovascular damage due to multiple risk factors. Our aim was to assess myocardial structure and function in pediatric KTx by conventional and speckle-tracking echocardiography (STE) in association with established cardiovascular risk factors.

METHODS

Forty-two KTx and 39 healthy age- and gender-matched children were evaluated. KTx recipients were further categorized according to the control of hypertension assessed by 24-h ambulatory blood pressure monitoring (ABPM). Subjects underwent pulse wave velocity (PWV) measurement, conventional echocardiography, and 2-dimensional STE. Left and right ventricular (LV, RV) global longitudinal strain (GLS), and LV circumferential strain (GCS) were measured. Glomerular filtration rate (eGFR) was calculated according to the Schwartz formula.

RESULTS

KTx patients had increased blood pressure and arterial stiffness. LV ejection fraction (EF) was preserved along with elevated LV mass index (LVMi) while LVGLS was significantly lower, whereas LVGCS and RVGLS were increased in KTx. Uncontrolled hypertensives had lower LVGLS compared to those with controlled hypertension. Using multiple forward stepwise regression analysis, 24-h SBP and relative wall thickness (RWT) were independent determinants of LVMi, whereas antihypertensive therapy, eGFR, and HOMA-IR were independent determinants of LVGLS.

CONCLUSIONS

Cardiac morphology and function show distinct changes after KTx. Along with comparable ventricular volumes, LV hypertrophy and subclinical myocardial dysfunction are present. Control of hypertension and kidney graft function are major factors of LV performance. STE may be useful to reveal early myocardial dysfunction in pediatric KTx. A higher resolution version of the Graphical abstract is available as Supplementary information.

Follow-Up of Blood Pressure, Arterial Stiffness, and GFR in Pediatric Kidney Transplant Recipients

Pediatric renal transplant recipients (RTx) were studied for longitudinal changes in blood pressure (BP), arterial stiffness by pulse wave velocity (PWV), and graft function.

Patients and Methods: 52 RTx patients (22 males) were included; office BP (OBP) and 24 h BP monitoring (ABPM) as well as PWV were assessed together with glycemic and lipid parameters and glomerular filtration rate (GFR) at 2.4[1.0–4.7] (T₁) and 9.3[6.3–11.8] years (T₂) after transplantation (median [range]).

Results: Hypertension was present in 67 and 75% of patients at T₁ and T₂, respectively. Controlled hypertension was documented in 37 and 44% by OBP and 40 and 43% by ABPM. Nocturnal hypertension was present in 35 and 30% at T₁ and T₂; 24 and 32% of the patients had masked hypertension, while white coat hypertension was present in 16 and 21% at T₁ and T₂, respectively. Blood pressure by ABPM correlated significantly with GFR and PWV at T₂, while PWV also correlated significantly with T₂ cholesterol levels. Patients with uncontrolled hypertension by ABPM had a significant decrease in GFR, although not significant with OBP. Anemia and increased HOMAi were present in ~20% of patients at T₁ and T₂.

Conclusion: Pediatric RTx patients harbor risk factors that may affect their cardiovascular health. While we were unable to predict the evolution of renal function based on PWV and ABPM at T₁, these risk factors correlated closely with GFR at follow-up suggesting that control of hypertension may have an impact on the evolution of GFR.

NT-proBNP as a Potential Marker of Cardiovascular Damage in Children with Chronic Kidney Disease

Assessing cardiovascular disease (CVD) in children with chronic kidney disease (CKD) is difficult. Great expectations have been associated with biomarkers, including the N-terminal pro-brain natriuretic peptide (NT-proBNP). This study aimed to determine the correlation between NT-proBNP and cardiovascular complications in children with CKD. Serum NT-proBNP, arterial stiffness, common carotid artery intima-media thickness (cIMT), echocardiographic (ECHO) parameters (including tissue Doppler imaging), and biochemical and clinical data were analyzed in 38 pediatric patients with CKD (21 boys, 12.2 ± 4.2 years). Mean NT-proBNP in CKD patients was 1068.1 ± 4630 pg/mL. NT-proBNP above the norm (125 pg/mL) was found in 16 (42.1%) subjects. NT-proBNP correlated with glomerular filtration rate (GFR) (r = −0.423, p = 0.008), and was significantly higher in CKD G5 (glomerular filtration rate grade) patients compared to CKD G2, G3, and G4 children (p = 0.010, p = 0.004, and p = 0.018, respectively). Moreover, NT-proBNP correlated positively with augmentation index (AP/PP: r = 0.451, p = 0.018, P2/P: r = 0.460, p = 0.016), cIMT (r = 0.504, p = 0.020), and E/E’ in ECHO (r = 0.400, p = 0.032). In multivariate analysis, logNT-proBNP was the only significant predictor of cIMT Z-score (beta = 0.402, 95CI (0.082–0.721), p = 0.014) and P2/P1 (beta = 0.130, 95CI (0.082–0.721), p = 0.014). Conclusions: NT-proBNP may serve as a possible marker of thickening of the carotid artery wall in pediatric patients with CKD. The final role of NT-proBNP as a biomarker of arterial damage, left ventricular hypertrophy, or cardiac diastolic dysfunction in CKD children needs confirmation in prospective studies.

Matrix metalloproteinase -2, -9 and arterial stiffness in children and adolescents: The role of chronic kidney disease, diabetes, and hypertension

Background and aims

Matrix metalloproteinases (MMPs) may contribute to the pathogenesis of arterial stiffness inducing extracellular matrix remodeling. We aimed to compare MMP-2 and -9 levels in children with chronic kidney disease (CKD), type 1 diabetes (without chronic kidney disease) and healthy control and to investigate associations of MMPs levels with cardiovascular risk factors and markers of arterial stiffness.

Methods

The study population included 33 CKD, 18 type 1 diabetes patients, and 24 healthy controls. MMP-2, MMP-9, office blood pressure, pulse wave analysis, and carotid-femoral pulse wave velocity (cfPWV) measurements were performed.

Results

MMP-2 levels were higher in the CKD compared to the diabetes and control groups (p < 0.05). MMP-9 levels did not differ among groups. In hypertensive individuals logMMP-2 independently associated with PWV z score (β = 0.744, 95%CI 0.105 to 2.921, p < 0.05) after adjustment for age, sex, GRF, and phosphate levels. Creatinine levels correlated positively with MMP-2 in the CKD (r = 0.39, p < 0.05) and negatively in the diabetes group (r = −0.72, p < 0.05). Cholesterol levels correlated with MMP-2 in the diabetes group (r = 0.70, p < 0.05). Phosphate levels correlated with MMP-2 level in the control group (r = 0.67, p < 0.05). In multivariate regression model adjusted for age and sex, including phosphate and GRF as covariates, only phosphate predicted logMMP-2 levels (β = 0.333, 95%CI 0.060 to 0.671, p < 0.05).

Conclusions

MMP-2 associated with arterial stiffness in the presence of hypertension, while the role of MMP-9 is less clear in children with CKD or type 1 diabetes. Whether up-regulation of MMPs could predict poor outcomes in young high-risk patient groups need to be confirmed by future studies.

Subtle cardiac dysfunction in nephropathic cystinosis: insight from tissue Doppler imaging and 2D speckle tracking echocardiography

BACKGROUND

Nephropathic cystinosis is a rare autosomal recessive lysosomal storage disorder that initially affects the kidney progressing to multi-organ failure due to accumulation of cystine in all tissue compartments.

OBJECTIVE

The main objective of this study is the evaluation of cardiac function in cystinosis patients using non-conventional echocardiographic modalities like pulsed wave tissue Doppler imaging (PW-TDI) and 2D speckle tracking echocardiography (2D-STE).

METHODS

This is a case control study conducted on fifteen patients with cystinosis and 15 normal controls. Echocardiography was done for all participants and PW-TDI was performed for measurement of S', E', A' velocities and myocardial performance index (MPI) at basal parts of septal, left ventricle (LV), and right ventricle (RV) free walls. 2D-STE was done for evaluation of global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) of LV. Mitral E and A velocities and tricuspid annular plane systolic excursion (TAPSE) were also measured.

RESULTS

The GLS, GRS, and S' velocity at basal septum and LV lateral wall were significantly lower in patients denoting LV systolic dysfunction (p = 0.005, p < 0.0001, p = 0.001, p = 0.006, respectively), while E/E' were significantly higher in patients group denoting LV diastolic dysfunction (p < 0.001). For RV function, TAPSE, S', and E' velocity were significantly lower in patients group (p 0.013, p < 0.01, p = 0.05, respectively) indicating RV systolic and diastolic dysfunction. The TDI-derived MPI for both LV and RV were significantly higher in patients group (p < 0.0001, p < 0.01, respectively) indicating both ventricular systolic and diastolic dysfunction. For prediction of cardiac dysfunction among patients, the receiver operating characteristic (ROC) curve showed that GRS ≤ 29% had sensitivity 93.3% and specificity 100%, GLS > - 20.1% had sensitivity 66.7% and specificity 93.3%, LV-E/E' >7.87 had sensitivity 73.3% and specificity 93.3%, and MPI-LV > 0.36 had sensitivity 100% and specificity 93.3% while MPI-RV > 0.29 had sensitivity 80% and specificity 93.3% and TAPSE ≤ 19 mm had sensitivity 80% and specificity 73.3%.

CONCLUSIONS

Patients with cystinosis have significant both left and right ventricular dysfunction, which can be better evaluated using the non-conventional echocardiographic modalities like TDI and 2D-STE for early detection of subtle cardiac dysfunction.

DNA Damage Response: A Molecular Lynchpin in the Pathobiology of Arteriosclerotic Calcification

Vascular calcification is a ubiquitous pathology of aging. Oxidative stress, persistent DNA damage, and senescence are major pathways driving both cellular and tissue aging, and emerging evidence suggests that these pathways are activated, and even accelerated, in patients with vascular calcification. The DNA damage response-a complex signaling platform that maintains genomic integrity-is induced by oxidative stress and is intimately involved in regulating cell death and osteogenic differentiation in both bone and the vasculature. Unexpectedly, a posttranslational modification, PAR (poly[ADP-ribose]), which is a byproduct of the DNA damage response, initiates biomineralization by acting to concentrate calcium into spheroidal structures that can nucleate apatitic mineral on the ECM (extracellular matrix). As we start to dissect the molecular mechanisms driving aging-associated vascular calcification, novel treatment strategies to promote healthy aging and delay pathological change are being unmasked. Drugs targeting the DNA damage response and senolytics may provide new avenues to tackle this detrimental and intractable pathology.

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.

Subclinical Organ Damage in Children and Adolescents with Hypertension: Current Guidelines and Beyond

High blood pressure (BP) is becoming a growing health issue even in children and adolescents. Moreover, BP elevation in youth frequently translates into children and adult hypertension contributing to the development of cardiovascular disease. The detection of early markers of vascular damage, potentially leading to overt cardiovascular disease, is important for clinical decisions about if and how to treat hypertension and can be useful in monitoring the effectiveness of the treatment. The purpose of this review is to summarize the actual knowledge about subclinical organ damage (SOD) in hypertensive children and adolescents and its association with cardiovascular disease in children and young adults. Our focus is especially put on left ventricular mass, pulse wave velocity, carotid intima-media thickness and microalbuminuria. We also want to address the scientific evidence about possible regression of SOD and cardiovascular risk with the use of behavioural and specific anti-hypertensive therapy. Indications from current guidelines are critically discussed.

Interdialytic weight gain and vasculopathy in children on hemodialysis: a single center study

BACKGROUND

Increased interdialytic weight gain (IDWG) has been associated with poor outcomes in adults, but its impact on hemodialysis vasculopathy in children is unknown.

METHODS

Nineteen patients (age 9 to 19 years old) with a median hemodialysis duration of 10.4 months were enrolled. Cardiovascular evaluation included left ventricular mass index (LVMI), pulse wave velocity (PWV), and carotid intima-media thickness (cIMT) measurements. PWV and cIMT were expressed as z-scores based on reference values in healthy children. Blood pressure (BP) evaluation consisted in a 24-h ambulatory BP monitoring. Mean IDGW and residual urine output during the 6 months prior to cardiovascular examination were calculated.

RESULTS

Increased cIMT, LVMI, and PWV was observed in 11 (57.9%), 7 (36.8%), and 5 (26.3%) patients respectively, while BP was normal in all patients. Median IDWG was 3.5% (1.8-6.7). Residual urine output and BP status did not significantly differ between patients with IDWG ≥ or < 4%. After linear regression, IDWG was correlated to cIMT z-score (r² = 0.485, p = 0.001), but not to PWV z-score (r² = 0.04, p = 0.415) and LVMI (r² = 0.092, p = 0.206). After univariate logistic regression, IDWG ≥ 4% was significantly associated to increased cIMT (above 1.65 SDS) (odds ratio 12.25, 95% confidence interval 1.08-138.988). The trend toward an increased cIMT with IDWG ≥ 4% was observed in both patients with short and long dialysis vintage.

CONCLUSIONS

High IDWG is associated with increased cIMT in hemodialyzed children independently of BP control and dialysis vintage. This observation reinforces the importance of interventions to avoid IDWG in hemodialyzed children.

Early cardiovascular manifestations in children and adolescents with autosomal dominant polycystic kidney disease: a single center study

BACKGROUND

This study aims to describe the cardiovascular manifestations in children with autosomal dominant polycystic kidney disease (ADPKD) and detect their relation with kidney disease and type of gene mutation.

METHODS

Twenty-one patients (7 to 19 years old) were included. Cardiovascular evaluation involved blood pressure (BP), indexed left ventricular mass (LVMI), pulse wave velocity (PWV), and carotid intima media thickness (cIMT) measurement. Patients were classified according to percentile reference values of these parameters in healthy children. The 95th percentile was the highest level of normal values. Glomerular filtration rate (GFR) and microalbuminuria were also measured.

RESULTS

Antihypertensive treatment, large LVMI, high PWV, and increased cIMT were observed in 6 (28.6%), 2 (9.5%), 4 (19%), and 8 (38.1%) patients respectively. Antihypertensive treatment was not associated with either high PWV or increased cIMT. Linear correlation was noticed between LVMI and PWV (r² = 0.243, p = 0.023) and also between LVMI and cIMT (r² = 0.203, p = 0.041). The median age of patients with high PWV, increased cIMT, and large LVMI was 9.5, 13, and 18 years old. GFR was normal in all patients. Patients with increased cIMT presented higher levels of urine microalbumin to creatinine ratio (p = 0.025). Genetic mutation was available in 18 patients. Antihypertensive treatment was more frequent in patients without PKD1 missense mutation (p = 0.044).

CONCLUSIONS

High PWV and increased cIMT indicating arterial stiffness and hypertrophic vasculopathy may be present in children with ADPKD regardless BP status, and prior to GFR decline, suggesting that vascular disease precedes chronic kidney disease in ADPKD.

The interplay between bone and vessels in pediatric CKD: lessons from a single-center study

OBJECTIVE

Mineral and bone disorders associated to chronic kidney disease (CKD-MBD) are a daily challenge for pediatric nephrologists, with a significant risk of long-term bone and vascular comorbidities.

METHODS

This single-center study is a prospective transversal evaluation of pediatric CKD patients of our center, part of the European 4C study. In addition to clinical and biochemical data, vascular and bone evaluation was performed: 24-h blood pressure assessment, carotid intima-media thickness (cIMT), pulse wave velocity (PWV), and high-resolution peripheral quantitative computed tomography (HR-pQCT) at the ultra-distal tibia. Results are presented as median (range).

RESULTS

At a median age of 12.9 years (10.2-17.9), SDS height of - 1.0 (- 3.3-1.2) and estimated glomerular filtration rate (eGFR) of 33 mL/min/1.73m² (11-72), 32 patients (8 girls) were evaluated. Median calcium, phosphate, parathyroid hormone (PTH), and 25 OHD3 levels were 2.44 mmol/L (2.24-2.78), 1.43 mmol/L (1.0-2.7), 80 pg/mL (9-359), and 70 nmol/L (32-116), respectively. Bivariate Spearman and backward multivariable analyses showed that calcium and bone trabecular thickness (Tb.Th), were positively associated with diastolic and mean arterial blood pressure (both for the 24 h, day and night assessment), whereas PTH and vitamin D did not predict blood pressure.

CONCLUSIONS

We show that the greater the serum levels of calcium, the greater the (diastolic and mean) blood pressure; moreover, the greater the Tb. Th, the greater the (diastolic and mean) blood pressure. The role of calcium supplements to explain such findings in early pediatric CKD can be discussed.

Methods to evaluate arterial structure and function in children - State-of-the art knowledge

BACKGROUND

With increasing rates of hypertension, obesity, and diabetes in the pediatric population, wide available, and reproducible methods are necessary to evaluate arterial structure and function in children and adolescents.

METHODS

MEDLINE/Pubmed was searched for articles published in years 2012-2017 on methodology of, current knowledge on, and limitations of the most commonly used methods to evaluate central, proximal and coronary arteries, as well as endothelial function in pediatric patients.

RESULTS

Among 1528 records screened (including 1475 records from years 2012 to 2017) 139 papers were found suitable for the review. Following methods were discussed in this review article: ultrasound measurements of the intima-media thickness, coronary calcium scoring using computed tomography, arterial stiffness measurements (pulse wave velocity and pulse wave analysis, carotid artery distensibility, pulse pressure, and ambulatory arterial stiffness index), ankle-brachial index, and methods to evaluate vascular endothelial function (flow-mediated vasodilation, peripheral arterial tonometry, Doppler laser flowmetry, and cellular and soluble markers of endothelial dysfunction).

CONCLUSIONS

Ultrasonographic measurement of carotid intima-media thickness and measurement of pulse wave velocity (by oscillometry or applanation tonometry) are highly reproducible methods applicable for both research and clinical practice with proved applicability for children aged ≥6 years or with height ≥120cm. Evaluation of ambulatory arterial stiffness index by ambulatory blood pressure monitoring is another promising option in pediatric high-risk patients. Clearly, further studies are necessary to evaluate usefulness of these and other methods for the detection of subclinical arterial damage in children.

[Diagnosis and management of chronic kidney disease in children: Guidelines of the French Society of Pediatric Nephrology]

These guidelines are intended to assist physicians in the care of children with chronic kidney disease (CKD), defined in children as in adults, regardless of its cause. Often silent for a long time, CKD can evolve to chronic renal failure or end-stage renal disease. Its management aims at slowing disease progression and treating CKD complications as soon as they appear. The different aspects of pediatric CKD care are addressed in these guidelines (screening, treatment, monitoring, diet, quality of life) as proposed by the French Society of Pediatric Nephrology. Highly specialized care provided in the hospital setting by pediatric nephrologists is not detailed.

Dyslipidemia, carotid intima-media thickness and endothelial dysfunction in children with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) predisposes to accelerated atherosclerosis that is measured by carotid artery intima-media thickness (cIMT) and brachial artery flow-mediated dilation (FMD). Information on the association of these parameters with dyslipidemia in pre-dialysis pediatric CKD is limited.

METHODS

Eighty patients aged 9.9 ± 3.2 years, with estimated glomerular filtration rate of 38.8 ± 10.8 ml/1.73 m(2)/min, and 42 pediatric controls underwent cross-sectional analysis of lipid profile, cIMT, and brachial artery FMD. Significant differences in these parameters between patients and controls were analyzed using Student's t test. Predictors of cIMT and dyslipidemia were assessed using linear and logistic regression respectively.

RESULTS

Patients had elevated blood levels of triglyceride and of total and LDL cholesterol than controls (P ≤ 0.001); 73.8 % were dyslipidemic. Mean cIMT was higher (0.421 ± 0.054 mm vs 0.388 ± 0.036 mm, P = 0.001) and brachial artery FMD was reduced (10.6 ± 4.9 % vs 18.9 ± 4.1 %, P < 0.0001) in patients compared with controls. On multivariate analysis, hypertension (OR 3.68, P = 0.044) and male gender (OR 10.21, P = 0.004) were associated with dyslipidemia; cIMT was significantly associated with LDL cholesterol (β = 28.36, P = 0.033).

CONCLUSION

Dyslipidemia was prevalent and cIMT significantly elevated in pre-dialysis pediatric CKD, indicating increased cardiovascular risk. Elevated LDL cholesterol predicted increased cIMT, strengthening the association between dyslipidemia and atherosclerosis in early CKD.

Chronic kidney disease in children

Chronic kidney disease (CKD) is a major health problem worldwide. Although relatively uncommon in children, it can be a devastating illness with many long-term consequences. CKD presents unique features in childhood and may be considered, at least in part, as a stand-alone nosologic entity. Moreover, some typical features of paediatric CKD, such as the disease aetiology or cardiovascular complications, will not only influence the child's health, but also have long-term impact on the life of the adult that they will become. In this review we will focus on the unique issues of paediatric CKD, in terms of aetiology, clinical features and treatment. In addition, we will discuss factors related to CKD that start during childhood and require appropriate treatments in order to optimize health outcomes and transition to nephrologist management in adult life.

Why are kids with lupus at an increased risk of cardiovascular disease?

Juvenile-onset systemic lupus erythematosus (SLE) is an aggressive multisystem autoimmune disease. Despite improvements in outcomes for adult patients, children with SLE continue to have a lower life expectancy than adults with SLE, with more aggressive disease, a higher incidence of lupus nephritis and there is an emerging awareness of their increased risk of cardiovascular disease (CVD). In this review, we discuss the evidence for an increased risk of CVD in SLE, its pathogenesis, and the clinical approach to its management.

Cardiovascular alterations do exist in children with stage-2 chronic kidney disease

BACKGROUND

Cardiovascular disease (CVD) is an important complication of chronic kidney disease (CKD) in children. However, it is not well known when and how cardiovascular alterations start.

METHODS

This cross-sectional, controlled study consisted of 25 patients and 28 healthy controls. 24-h ambulatory blood pressure monitoring, aortic pulse wave velocity (aPWV), carotid intima-media thickness (cIMT) and carotid distensibility (distensibility coefficient and β stiffness index), and echocardiography were assessed to evaluate CVD. Routine biochemical parameters, fibroblast growth factor-23 (FGF23) and high sensitive C- reactive protein were measured to determine cardiovascular risk factors.

RESULTS

Hypertension was found in 12 patients (48 %). Patients had higher FGF23 levels and aPWV-standard deviation score (SDS) as compared to the controls (p = 0.003 and p = 0.002, respectively). Aortic PWV-SDS was predicted by increased daytime systolic blood pressure load (β = 0.512, p = 0.009, R ² = 0.262). Neither cIMT nor distensibility differed between the groups; however, older age and high level of FGF23 were independent predictors of β stiffness index in patients (β = 0.507, p = 0.005, R ² = 0.461 and β = 0.502, p = 0.005, R ² = 0.461, respectively). As compared to controls, patients had worse left ventricular diastolic function [lower E/A ratio p = 0.006) and increased left atrial dimension (p < 0.001)].

CONCLUSIONS

Cardiovascular deteriorations appear in children with stage-2 CKD. Good control of BP and decreasing the level of FGF23 may be useful to slow down the progression of cardiovascular complications.

Long-term effects of paediatric kidney transplantation

Renal transplantation in paediatric patients usually provides excellent short-term and medium-term results. Early diagnosis of chronic kidney disease and active therapy of end-stage renal disease before and after transplantation enables the majority of children to grow and develop normally. The adverse effects of immunosuppressive medication and reduced graft function might, however, hamper long-term outcomes in these patients and can lead to metabolic complications, cardiovascular disease, reduced bone health, and malignancies. The neurocognitive development and quality of life of paediatric transplant recipients largely depend on the primary diagnosis and on graft function. Poor adherence to immunosuppression is an important risk factor for graft loss in adolescents, and controlled transition to adult care is of utmost importance to ensure a continued normal life. In this Review, we discuss the outcomes and long-term effects of renal transplantation in paediatric recipients, including consequences on growth, development, bone, metabolic, and cardiovascular disorders. We discuss the key problems in the care of paediatric renal transplant recipients and the remaining challenges that should be the focus of future research.

Aortic Pulse Wave Velocity in Healthy Children and Adolescents: Reference Values for the Vicorder Device and Modifying Factors

BACKGROUND

Aortic pulse wave velocity (PWV), an indicator of arterial stiffness, independently predicts cardiovascular mortality risk in adults. Arterial stiffening advances with age and seems accelerated in children with certain disease conditions such as chronic kidney disease or diabetes. The Vicorder, an oscillometric device to measure PWV, has been validated in children, but reference values in a large pediatric cohort, association to carotid stiffness and influence of individual and family risk factors have not been determined.

METHODS

Pulse waves were captured in 1,003 healthy children (aged 6-18 years) in 6 centers and gender-specific reference data normalized to age/height were constructed. In 589 children carotid distensibility and intima media thickness were measured. Gestational and family history was reported.

RESULTS

PWV correlated with age (r = 0.57, P < 0.0001) with significant gender-related differences starting at age 9. Further significant correlations were seen for height, weight, body mass index, blood pressure, pulse pressure, and heart rate. Independent predictors for PWV in a multivariate regression analysis were gender, age, height, weight, mean arterial pressure, and heart rate. Risk factors for higher PWV included small for gestational age at birth, secondhand smoking, parental hypertension, and obesity. PWV showed weak correlations with 2 of the carotid distensibility measures, but not with intima media thickness.

CONCLUSION

This study defines reference values for PWV captured by the Vicorder device in children and adolescents and reveals associations with potential cardiovascular risk factors in a healthy population. Gender-specific percentiles for age/height will allow for the assessment of pediatric cohorts using this oscillometric method.

Etiology and management of dyslipidemia in children with chronic kidney disease and end-stage renal disease

Lipids are essential components of cell membranes, contributing to cell fuel, myelin formation, subcellular organelle function, and steroid hormone synthesis. Children with chronic kidney disease (CKD) and end-stage renal disease (ESRD) exhibit various co-morbidities, including dyslipidemia. The prevalence of dyslipidemias in children with CKD and ESRD is high, being present in 39-65% of patients. Elevated lipid levels in children without renal disease are a risk factor for cardiovascular disease (CVD), while the risk for CVD in pediatric CKD/ESRD is unclear. The pathogenesis of dyslipidemia in CKD features various factors, including increased levels of triglycerides, triglyceride-rich lipoproteins, apolipoprotein C3 (ApoC-III), decreased levels of cholesterylester transfer protein and high-density lipoproteins, and aberrations in serum very low-density and intermediate-density lipoproteins. If initial risk assessment indicates that a child with advanced CKD has 2 or more co-morbidities for CVD, first-line treatment should consist of non-pharmacologic management such as therapeutic lifestyle changes and dietary counseling. Pharmacologic treatment of dyslipidemia may reduce the incidence of CVD in children with CKD/ESRD, but randomized trials are lacking. Statins are the only class of lipid-lowering drugs currently approved by the U.S. Food and Drug Administration (FDA) for use in the pediatric population. FDA-approved pediatric labeling for these drugs is based on results from placebo-controlled trial results, showing 30-50% reductions in baseline low-density lipoprotein cholesterol. Although statins are generally well tolerated in adults, a spectrum of adverse events has been reported with their use in both the clinical trial and post-marketing settings.

The vascular phenotype of children with systemic lupus erythematosus

BACKGROUND

The increased risk of cardiovascular disease (CVD) in adults with systemic lupus erythematosus (SLE) has been known since the 1970s, but studies in juvenile-onset SLE (JSLE) have reported conflicting results and more data are needed. The aim of this cross-sectional study was to establish the baseline risk of CVD in a cohort of UK patients with JSLE.

METHODS

Data were collected to establish disease duration, disease activity, medication use and activity levels, as well as demographic data, including family history of CVD. Vascular phenotype was established using well-validated measures of carotid intima media thickness (cIMT) and pulse wave velocity (PWV).

RESULTS

In total, 45 children (39 female; mean age 13.5 ± 2.9 years) with JSLE were recruited to the study. Of these, 24 had a history of biopsy-proven lupus nephritis and five had an estimated glomerular filtration rate of <90 ml/min/1.73 m(2). Comparison of these JSLE patients with healthy controls previously scanned at our hospital revealed that the cIMT value was significantly higher in the former (0.45 vs. 0.37 mm, respectively; p < 0.0001). This difference was associated with the use of antihypertensives (p = 0.04) and higher or lower doses of prednisolone (p < 0.0001). PWV was not significantly different in the patient and control group (5.27 vs. 5.34 m/s, respectively; p = 0.77). In the patient group, the mean body mass index percentile was 65.63 ± 28.8, and the median physical activity score was 1,773 (676-2,854) metabolic equivalents of task (METs). None of the patients admitted to cigarette smoking, and ten had a positive family history of cardiovascular disease (CVD).

CONCLUSION

This study shows that our patients with JSLE had increased cIMT without an increase in PWV, suggesting possible early adaptive changes in JSLE. Follow-up data are needed to determine whether these changes result in clinically significant CVD.

Predictors of renal replacement therapy and mortality in children with chronic kidney disease

Objectives:

To study the epidemiology of chronic kidney disease (CKD) in children, and to look for risk factors to predict renal replacement therapy (RRT) and mortality.

Methods:

This is a retrospective cohort study conducted at King Abdulaziz University Hospital, Jeddah, Saudi Arabia between 2006 and 2014, where the files of 1,000 children with CKD were reviewed. We determined the effect of consanguinity and hypertension, and being a Saudi indigene on mortality and RRT. We compared children with congenital versus non-congenital causes of CKD.

Results:

The mean±standard deviation age at presentation was 4.9±4.3 years. The median duration of follow up was 1.5 (interquartile range [IQR]: 0.4-4.0) years. Only 9.7% of children received RRT, and 8.3% died. The underlying etiology for CKD was congenital in 537 children. The congenital CKD group presented at a younger age group (3.5±4.0 versus 6.6±3.9 years, p<0.0001), had more advanced stages of CKD (p<0.0001), higher rates of consanguinity (75.4% versus 47.1%, p<0.0001), and RRT (p<0.004) than children with non-congenital CKD. Risk factors for RRT among children with CKD include being a Saudi indigene (relative risk [RR]=1.49, 95% confidence interval (CI): 1.01-2.21), and hypertensive (RR=5.29, 95% CI: 3.54-7.91). The risk factor for mortality was hypertension (RR=2.46, 95% CI: 1.66-3.65).

Conclusion:

Congenital causes of CKD represent the main etiology of CKD in children living in the western province of Saudi Arabia. Significant risk factors for RRT include congenital CKD, Saudi nationality, and hypertension. Hypertension is also a predictor of mortality in children with CKD.

Calcific uraemic arteriolopathy: a rare disease with a potentially high impact on chronic kidney disease-mineral and bone disorder

Calciphylaxis [calcific uraemic arteriolopathy (CUA)] is a rare disease at the interface of nephrology, dermatology and cardiology. CUA most often occurs in adult dialysis patients. It is only rarely seen in patients without relevant chronic kidney disease, and only anecdotal reports about childhood calciphylaxis have been published. Clinically, CUA is characterized by a typical cascade, starting with severe pain in initially often inconspicuous skin areas, followed by progressive cutaneous lesions that may develop into deep tissue ulcerations. The typical picture is a mixture of large retiform ulceration with thick eschar surrounded by violaceous, indurated, tender plaques. The histopathological picture reveals arteriolar, often circumferential, calcification and extensive matrix remodelling of the subcutis. These findings explain the macroscopic correlation between skin induration and ulceration. The prognosis in CUA patients is limited due to underlying comorbidities such as uraemic cardiovascular disease and infectious complications. The etiology of CUA is multifactorial, and imbalances between pro- and anti-calcification factors, especially in the setting of end-stage renal disease play an outstanding role. Oral anticoagulant treatment with vitamin K antagonists is a predominant CUA trigger factor. It is speculative as to why children and adolescents only develop calciphylaxis in exceptional cases, although a seldom usage of vitamin K antagonists and the preserved mineral buffering capacity of the growing skeleton may be protective.

Acute effects of ultrafiltration on aortic mechanical properties determined by measurement of pulse wave velocity and pulse propagation time in hemodialysis patients

Objective:

The effects of acute hemodialysis session on pulse wave velocity are conflicting. The aim of the current study was to assess the acute effects of ultrafiltration on the aortic mechanical properties using carotid-femoral (aortic) pulse wave velocity and pulse propagation time.

Methods:

A total of 26 (12 women, 14 men) consecutive patients on maintenance hemodialysis (mean dialysis duration: 40.7±25.6 (4-70) months) and 29 healthy subjects (13 women, 16 men) were included in this study. Baseline blood pressure, carotid-femoral (aortic) pulse wave velocity, and pulse propagation time were measured using a Complior Colson device (Createch Industrie, France) before and immediately after the end of the dialysis session.

Results:

While systolic blood pressure, diastolic blood pressure, mean blood pressure, pulse pressure, and pulse wave velocity were significantly higher in patients on hemodialysis than in healthy subjects, pulse propagation time was significantly higher in healthy subjects. Although body weight, systolic blood pressure, diastolic blood pressure, mean blood pressure, pulse pressure, and pulse wave velocity were significantly decreased, heart rate and pulse propagation time were significantly increased after ultrafiltration. There was a significant positive correlation between pulse wave velocity and age, body height, waist circumference, systolic blood pressure, diastolic blood pressure, mean blood pressure, pulse pressure, and heart rate.

Conclusion:

Although hemodialysis treatment may chronically worsen aortic mechanical properties, ultrafiltration during hemodialysis may significantly improve aortic pulse wave velocity, which is inversely related to aortic distensibility and pulse propagation time.