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

Hypertension and Cardiovascular Risk Among Children with Chronic Kidney Disease

PURPOSE OF REVIEW

Cardiovascular disease is the most common cause of mortality across the lifespan of children with chronic kidney disease (CKD). Hypertension is a common and important contributor, but other factors such as obesity, dyslipidemia and mineral bone disease play a role. This narrative review focusses on studies published in the past five years that have investigated hypertension and cardiovascular risk among children with CKD.

RECENT FINDINGS

Cohort studies such as Chronic Kidney Disease in Children (CKiD) and Cardiovascular Comorbidity in Children with CKD (4C) have continued to develop our understanding of blood pressure (BP) phenotypes, and of progressive changes in the structure and function of the heart and blood vessels occurring in children with CKD. Metabolic risk factors, such as dyslipidemia, may represent an under-recognized component of care. Trial data are less common than observational evidence, but support lifestyle interventions currently used, mainly the low sodium dietary approaches to stop hypertension (DASH) diet. The findings of the recently reported Hypertension Optimal Treatment in Children with Chronic Kidney Disease trial (HOT-KID) are described in relation to the use of office BP treatment targets. Cardiovascular health is critical to the long-term outcomes of children with CKD. Recognizing and treating hypertension remains a critical component to improving outcomes, along with measures to improve concurrent cardiovascular risk factors. Some cardiovascular changes may not be reversible with transplantation and further research is needed for children at all stages of CKD.

Sex difference in nocturnal blood pressure dipping in adolescents with varying degrees of adiposity

BACKGROUND

For adolescents, abnormal dipping patterns in blood pressure (BP) are associated with early-onset organ damage and a higher risk of cardiovascular disorders in adulthood. Obesity is one of the most common reasons for abnormal BP dipping in young people. However, it is unknown whether the severity of obesity is associated with BP dipping status and whether this association is sex-dependent.

METHODS

499 participants between 12 and 17 years old with overweight or obesity underwent ambulatory blood pressure monitoring (ABPM) between April 2018 and January 2019 in Beijing and Baoding. Participants were grouped by body mass index (BMI) into overweight (BMI 85th-95th percentile), obese (BMI ≥ 95th percentile) and severely obese (BMI ≥ 120% of 95th percentile or ≥ 35 kg/m2) groups. Non-dipping was defined as a < 10% reduction in BP from day to night. The interaction effect between sex and obesity degree was also analyzed.

RESULTS

326 boys and 173 girls were included, of whom 130 were overweight, 189 were obese, and 180 were severely obese. Girls with severe obesity had a higher prevalence of non-dipping, but boys showed no significant differences in BP dipping status between obesity categories. In addition, as obesity severity went up, a more evident increase in night-time SBP was observed in girls than in boys.

CONCLUSIONS

Severely obese is associated with a higher prevalence of non-BP dipping patterns in girls than in boys, which suggests that the relationship between the severity of obesity and BP dipping status might be sex-specific.

24-h ambulatory blood pressure readings and associations with albuminuria in youth with type 2 diabetes: A cross sectional analysis from the iCARE cohort

AIMS

To evaluate associations between 24-h ambulatory blood pressure monitor (ABPM) data vs. single casual blood pressure (BP) and albuminuria in youth with type 2 diabetes.

METHODS

A cross-sectional analysis of youth with type 2 diabetes 10-<18 yrs. from the iCARE cohort.

MAIN EXPOSURES

daytime HTN (+/- nocturnal), isolated nocturnal HTN and single casual BP.

MAIN OUTCOME

non-orthostatic urine albumin: creatinine ratio (ACR) ≥ 3 mg/mmol and log-transformed urine ACR. Regressions evaluated associations between 1. HTN status based on ABPM and log-transformed urine ACR (continuous) and 2. ABPM-derived BP z-scores and casual BPcentiles and albuminuria status (categorical).

RESULTS

Of 281 youth included, 19.6 % had daytime HTN (+/- nocturnal), and 28.5 % isolated nocturnal HTN on 24-h ABPM. In multivariate linear regression, HTN (ABPM) (ß = 0.553; p = 0.001), duration of diabetes (ß = 0.857; p = 0.02), HbA1c (ß = 1.172; p ≤0.0001) and ACEI/ARB use (ß = 3.94; p < 0.0001) were positively associated with log-transformed ACR; (R2 = 0.184). In logistic regression analysis, all ABPM LMS z-scores were positively associated with albuminuria; casual BPcentile was not significant.

CONCLUSIONS

Youth with type 2 diabetes have high rates of HTN based on 24-ABPM data. ABPM-derived measures of BP are associated with albuminuria. These data support the routine use of ABPM devices to diagnose hypertension in youth with type 2 diabetes.

Role of hypertension in progression of pediatric CKD

Hypertension is frequent in children with chronic kidney disease (CKD). Its prevalence varies according to CKD stage and cause. It is relatively uncommon in children with congenital kidney disease, while acquired kidney disease is associated with a higher prevalence of hypertension. Studies in children with CKD utilizing ambulatory blood pressure monitoring also showed a high prevalence of masked hypertension. Uncontrolled and longstanding hypertension in children is associated with progression of CKD. Aggressive treatment of high blood pressure should be an essential part of care to delay CKD progression in children.

Prevalence of Pediatric Masked Hypertension and Risk of Subclinical Cardiovascular Outcomes: A Systematic Review and Meta-Analysis

Masked hypertension (MH) occurs when office blood pressure is normal, but hypertension is confirmed using out-of-office blood pressure measures. Hypertension is a risk factor for subclinical cardiovascular outcomes, including left ventricular hypertrophy, increased left ventricular mass index, carotid intima media thickness, and pulse wave velocity. However, the risk factors for ambulatory blood pressure monitoring defined MH and its association with subclinical cardiovascular outcomes are unclear. A systematic literature search on 9 databases included English publications from 1974 to 2023. Pediatric MH prevalence was stratified by disease comorbidities and compared with the general pediatric population. We also compared the prevalence of left ventricular hypertrophy, and mean differences in left ventricular mass index, carotid intima media thickness, and pulse wave velocity between MH versus normotensive pediatric patients. Of 2199 screened studies, 136 studies (n=28 612; ages 4-25 years) were included. The prevalence of MH in the general pediatric population was 10.4% (95% CI, 8.00-12.80). Compared with the general pediatric population, the risk ratio (RR) of MH was significantly greater in children with coarctation of the aorta (RR, 1.91), solid-organ or stem-cell transplant (RR, 2.34), chronic kidney disease (RR, 2.44), and sickle cell disease (RR, 1.33). MH patients had increased risk of subclinical cardiovascular outcomes compared with normotensive patients, including higher left ventricular mass index (mean difference, 3.86 g/m2.7 [95% CI, 2.51-5.22]), left ventricular hypertrophy (odds ratio, 2.44 [95% CI, 1.50-3.96]), and higher pulse wave velocity (mean difference, 0.30 m/s [95% CI, 0.14-0.45]). The prevalence of MH is significantly elevated among children with various comorbidities. Children with MH have evidence of subclinical cardiovascular outcomes, which increases their risk of long-term cardiovascular disease.

Masked Hypertension in Healthy Children and Adolescents: Who Should Be Screened?

PURPOSE OF REVIEW

The goal is to review masked hypertension (MH) as a relatively new phenomenon when patients have normal office BP but elevated out-of-office BP. Firstly, it was described in children in 2004. It has received increased attention in the past decade.

RECENT FINDINGS

The prevalence of MH in different pediatric populations differs widely between 0 and 60% based on the population studied, definition of MH, or method of out-of-office BP measurement. The highest prevalence of MH has been demonstrated in children with chronic kidney disease (CKD), obesity, diabetes, and after heart transplantation. In healthy children but with risk factors for hypertension such as prematurity, overweight/obesity, diabetes, chronic kidney disease, or positive family history of hypertension, the prevalence of MH is 9%. In healthy children without risk factors for hypertension, the prevalence of MH is very low ranging 0-3%. In healthy children, only patients with the following clinical conditions should be screened for MH: high-normal/elevated office BP, positive family history of hypertension, and those referred for suspected hypertension who have normal office BP in the secondary/tertiary center.

Prevalence of masked hypertension and its association with left ventricular hypertrophy in children and young adults with chronic kidney disease: a systematic review and meta-analysis

OBJECTIVES

There are limited studies using ambulatory blood pressure monitoring (ABPM) to assess blood pressure (BP) status in young patients with chronic kidney disease (CKD) on dialysis or after kidney transplantation. The aim of this meta-analysis is to estimate the prevalence of both white-coat hypertension (WCH) and masked hypertension, along with the prevalence of left ventricular hypertrophy (LVH), in children and young adults with CKD on dialysis or after kidney transplantation.

METHODS

We performed a systematic review and meta-analysis of observational studies assessing the prevalence of BP phenotypes using ABPM, in children and young adults with CKD stages 2-5d. Records were identified by search in databases (Medline, Web of Science, CENTRAL) and sources of grey literature, until 31 December 2021. A random-effects meta-analysis of proportions (double arcsine transformation) was conducted.

RESULTS

Ten studies were included in the systematic review, reporting data from 1140 individuals (children and young adults with CKD with a mean age of 13.79 ± 4.35 years). Masked hypertension and WCH were diagnosed in 301 and 76 patients, respectively. It was estimated an overall pooled masked hypertension prevalence of 27% [95% confidence interval (95% CI) 18-36, I2  = 87%] and an overall pooled WCH prevalence of 6% (95% CI 3-9, I2  = 78%). Among kidney transplant recipients, masked hypertension had a prevalence of 29% (95% CI 14-47, I2  = 86%). The prevalence of LVH was found 28% (95% CI 0.19-0.39) in a total of 238 CKD patients with ambulatory hypertension. In 172 CKD patients with masked hypertension, LVH was present in 49, with the estimated prevalence being 23% (95% CI 0.15-0.32).

CONCLUSION

Masked hypertension has a significant prevalence in children and young adults with CKD. Masked hypertension carries an adverse prognosis, with an increased risk of LVH, warranting clinical attention when assessing cardiovascular risk in this population. Therefore, ABPM and echocardiography is of high importance when assessing BP status in children with CKD.

PROTOCOL REGISTRATION NUMBER DOI

10.17605/OSF.IO/UKXAF.

Longitudinal follow-up on vascular morphology and function in children with kidney transplants

AIM

Our aim was to evaluate cardiovascular risk profile in 42 children with kidney transplants (KT) at the Queen Silvia Children's Hospital, Gothenburg Sweden.

METHODS

Forty-two children (7.1-18 years) with KT, time from transplantation 3.5 (0.9-13) years, were examined at inclusion and annually for three consecutive years. Eighteen matched controls were examined once. Cardiovascular phenotyping included ultra-high-frequency ultrasound (UHFUS), pulse wave velocity (PWV), and endothelial function.

RESULTS

Children with KT had higher body mass index (BMI) z-score and blood pressure (BP) z-score than healthy controls (BMI z-score: 0.4 ± 1.0 and - 0.2 ± 0.9, respectively, p = 0.02; SBP z-score: 0.5 ± 0.9 and - 0.8 ± 0.7; DBP z-score: 0.7 ± 0.7 and - 0.3 ± 0.5, respectively, p < 0.001). BP z-score decreased significantly over 3 years; other vascular markers remained unchanged. PWV and carotid intima thickness (IT) were higher in children with KT compared to healthy controls. Children with pre-emptive KT had lower radial IT and dorsal pedal media thickness (MT) compared to children with preceding dialysis.

CONCLUSION

Children with KT show increased cardiovascular risk parameters, not increasing over time. Children on dialysis before KT have more pronounced vascular changes than those with pre-emptive KT, suggesting pre-emptive transplantation more beneficial for cardiovascular health.

Masked Hypertension in Pediatric Heart Transplant Recipients

BACKGROUND

Masked hypertension (HTN), especially, isolated nocturnal HTN (INH) has been shown to be a risk factor for cardiovascular disease (CVD) but is not studied well in pediatric heart transplant (PHT) patients. Ambulatory blood pressure monitoring (ABPM) is known to identify patients with HTN but is not used routinely in PHT.

METHODS

A single-center, prospective, cross-sectional study of PHT recipients was performed to observe the incidence of masked HTN using 24-h ABPM. The relationship between ABPM parameters and clinical variables was assessed using Spearman correlation coefficient. p value < 0.05 was considered significant.

RESULTS

ABPM was performed in 34 patients, mean age 14 ± 5 years, median 5.5 years post-PHT. All patients had normal cardiac function, left ventricular mass index and blood pressure measurements in the clinic. Four patients had known prior HTN and on medications, one of them was uncontrolled. Of the remaining 30 patients, 18 new patients were diagnosed with masked HTN, of which 14 had INH. Diurnal variation was abnormal in 82% (28/34) patients. 24-h diastolic blood pressure (DBP) index correlated with glomerular filtration rate (GFR) (r = - 0.44, p = 0.01). There was no correlation between other ABPM parameters with tacrolimus trough levels.

CONCLUSIONS

ABPM identified masked HTN in 60% of patients, with majority being INH. Abnormal circadian BP patterns were present in 82% and an association was found between GFR and DBP parameters. HTN, especially INH, is under-recognized in PHT recipients and ABPM has a role in their long-term care.

Ambulatory Blood Pressure Monitoring in Pediatrics, an Update on Interpretation and Classification of Hypertension Phenotypes

PURPOSE OF REVIEW

This review highlights the major changes reflected in the 2022 American Heart Association (AHA) Scientific Statement on Ambulatory Blood Pressure Monitoring (ABPM) in Children and Adolescents with a specific focus on the newly defined phenotypes of hypertension and their epidemiology and associated outcomes.

RECENT FINDINGS

The 2022 AHA guidelines' most notable changes include the following: (1) alignment of blood pressure (BP) thresholds with the 2017 American Academy of Pediatrics (AAP) clinical practice guidelines, 2017 American College of Cardiology (ACC)/AHA hypertension guidelines, and 2016 European Society of Hypertension (ESH) pediatric recommendations; (2) expansion of the use of ABPM to diagnose and phenotype pediatric hypertension in all pediatric patients; (3) removal of BP loads from diagnostic criteria; and (4) simplified classification of new hypertension phenotypes to prognosticate risks and guide clinical management. Recent studies suggest that utilizing the 2022 AHA pediatric ABPM guidelines will increase the prevalence of pediatric ambulatory hypertension, especially for wake ambulatory hypertension in older, taller males and for nocturnal hypertension in both males and females ≥ 8 years of age. The new definitions simplify the ambulatory hypertension criteria to include only the elements most predictive of future health outcomes, increase the sensitivity of BP thresholds in alignment with recent data and other guidelines, and thus make hypertension diagnoses more clinically meaningful. This guideline will also aid in the transition of adolescents and young adults to adult medical care. Further studies will be necessary to study ambulatory BP norms in a more diverse pediatric population and evaluate the impact of these guidelines on prevalence and future outcomes.

Arterial stiffness and blood pressure increase in pediatric kidney transplant recipients

BACKGROUND

Pulse wave velocity (PWV) is a measure of arterial stiffness. We investigated PWV and blood pressure (BP) to determine to what extent BP changes contribute to arterial stiffness, and secondly, to identify influencing factors on BP in children after kidney transplantation.

METHODS

Seventy children ≥ 2.5 years post-transplantation with at least two PWV measurements were included. Changes of systolic (Δ SBP) and diastolic BP (Δ DBP) were classified into "stable/decreasing," "1-10 mmHg increase," and " > 10 mmHg increase." Linear mixed modeling for PWV z-score (PWVz) adjusted either for Δ SBP or Δ DBP was performed. An extended dataset with monthly entries of BP, immunosuppression, and creatinine was obtained in 35 participants over a median of 74 months to perform linear mixed modeling for SBP and DBP.

RESULTS

PWVz increased with a rate of 0.11/year (95% CI 0.054 to 0.16). Compared to participants with stable BP, those with 1-10-mmHg SBP and DBP increase showed a higher PWVz of 0.59 (95% CI 0.046 to 1.13) and 0.86 (95% CI 0.43 to 1.30), respectively. A > 10-mmHg BP increase was associated with an even higher PWVz (SBP β = 0.78, 95% CI 0.22 to 1.34; DBP β = 1.37, 95% CI 0.80 to 1.94). Female sex and participants with lower eGFR showed higher PWVz. In the extended analysis, DBP was positively associated with cyclosporin A and everolimus trough levels.

CONCLUSIONS

A higher increase of PWV is seen in patients with greater BP increase, with higher cyclosporin A and everolimus trough levels associated with higher BP. This emphasizes the role of BP as a modifiable risk factor for the improvement of cardiovascular outcome after transplantation. A higher resolution version of the Graphical abstract is available as Supplementary information.

Racial-ethnic diversity in ambulatory blood pressure monitoring in children with chronic kidney disease

BACKGROUND

Black adults with chronic kidney disease (CKD) have higher rates of hypertension as compared to White adults with CKD. Little is known of how race and ethnicity associate with the prevalence of hypertension in pediatric CKD patients. The aim was to compare ambulatory blood pressure monitoring (ABPM) results for patients with CKD enrolled in the Chronic Kidney Disease in Children (CKiD) study across racial-ethnic groups.

METHODS

Patients from the CKiD study who identified as non-Hispanic White, non-Hispanic Black, or Hispanic were included to analyze differences in ABPM results across these racial-ethnic groups. The outcomes were fitted using 3 progressively adjusted models.

RESULTS

This study included 501 CKiD participants with at least one successful ABPM study. Compared to White participants, Black participants had 4.2 mmHg higher mean sleep systolic blood pressure and 2.7 mmHg higher mean sleep diastolic blood pressure (p = 0.001 and p = 0.004, respectively). Additionally, Black participants had higher odds of abnormal wake systolic load (OR 1.88, 1.21-2.91, p = 0.005), wake diastolic load (OR 1.68, 1.03-2.73, p = 0.04), sleep systolic load (OR 2.19, 1.36-3.5, p = 0.001), sleep diastolic load (OR 2.01, 1.28-3.15, p = 0.002), systolic non-dipping (OR 2.02, 1.31-3.10, p = 0.001), and diastolic non-dipping (OR 2.69, 1.60-4.51, p < 0.001). Compared to White participants, Hispanic participants demonstrated only a lower sleep diastolic load (OR 0.54, 0.31-0.95, p = 0.03).

CONCLUSIONS

Black children with CKD have higher absolute nocturnal blood pressures and higher rates of abnormal dipping. Further studies are needed to determine the etiology of these differences and the clinical implications of racial-ethnic differences in ABPM outcomes within the pediatric CKD population. A higher resolution version of the Graphical abstract is available as Supplementary information.

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.

Nocturnal Hypertension in Children With Chronic Kidney Disease Is Common and Associated With Progression to Kidney Replacement Therapy

BACKGROUND

Nocturnal hypertension is a risk factor for chronic kidney disease (CKD) progression among adults. In children, effects of nocturnal hypertension on CKD progression is less studied.

METHODS

We investigated the relationships between nocturnal, daytime, or sustained hypertension and progression to kidney replacement therapy in children using Cox proportional hazards models. Nocturnal and diurnal hypertension respectively defined as: mean blood pressure >95th percentile and/or load >25% for either systolic or diastolic blood pressure within sleep or wake periods.

RESULTS

One thousand five hundred seventy-seven ambulatory blood pressure monitoring studies from 701 CKiD participants were reviewed. Nighttime, daytime, and both types of hypertension were 19%, 7%, and 33%, respectively. Participants with both daytime and nocturnal hypertension had the highest risk of kidney replacement therapy. Among children with CKD, compared with those who were normotensive, those with isolated nocturnal hypertension had a hazard ratio of 1.49 ([CI, 0.97-2.28]; P=0.068) while those with both daytime and nocturnal hypertension had a HR of 2.23 ([CI, 1.60-3.11]; P<0.001) when adjusted for age, race, sex, and baseline proteinuria and glomerular filtration. Estimates for risk were similar among glomerular and nonglomerular participants but not significant in glomerular due to smaller sample size.

CONCLUSIONS

The presence of both daytime and nocturnal hypertension is significantly associated with risk of kidney replacement therapy. Our study confirms the utility of ambulatory blood pressure monitoring in children with CKD. Identifying and controlling both daytime and nocturnal hypertension using ambulatory blood pressure monitoring may improve outcomes and delay CKD progression in this population.

Increased risk for kidney sequelae surrogates in survivors of Wilms tumor

BACKGROUND

There is evidence of increased risk of hypertension, albuminuria, and development of chronic kidney disease (CKD) in long-term follow-up of survivors of Wilms tumor (WT). However, most studies were conducted in heterogeneous groups, including patients with solitary kidney. In addition, little is known about tubular dysfunction. This study aimed to investigate kidney sequelae, including CKD development, hypertension, and glomerular and tubular damage in WT survivors.

METHODS

This cross-sectional, single-center study included 61 patients treated for WT. Surrogates for kidney sequelae were defined as presence of at least one of the following: decrease in GFR for CKD, hypertension detected by ambulatory blood pressure monitoring, albuminuria (albumin-to-creatinine ratio [ACR] > 30 mg/g), or increase in at least one tubular biomarker (beta-2-microglobulin, neutrophil gelatinase-associated lipocalin, kidney injury marker-1, and liver fatty acid-binding protein) in 24-h urine.

RESULTS

Median age of patients was 11.7 years, with median follow-up of 8.8 years. Thirty-eight patients (62%) had at least one surrogate for kidney sequelae. Twenty-four patients (39%) had CKD, 14 patients (23%) had albuminuria, 12 patients (21%) had hypertension, and 11 patients (18%) had tubular damage. Urine ACR was significantly higher in patients with advanced tumor stage and patients with nephrotoxic therapy than their counterparts (p < 0.05), but neither eGFR nor tubular biomarkers showed any association with tumor- or treatment-related factors.

CONCLUSIONS

A considerable number of patients with WT have kidney sequelae, especially early-stage CKD with a high prevalence. Albuminuria emerges as a marker associated with tumor stages and nephrotoxic treatment. A higher resolution version of the Graphical abstract is available as Supplementary information.

Arterial Stiffness and Chronic Kidney Disease Progression in Children

BACKGROUND AND OBJECTIVES

CKD has been linked to increased arterial stiffness in adults, but data in children with CKD remain conflicting. We aimed to investigate the longitudinal dynamics and determinants of pulse wave velocity in children with CKD and its association with CKD progression.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We performed an analysis of the Cardiovascular Comorbidity in Children with Chronic Kidney Disease (4C) study, which prospectively followed children aged 6-17 years with CKD stages 3-5. Follow-up was censored at the time of KRT initiation. Two separate analyses were performed: with absolute pulse wave velocity (primary outcome) and with pulse wave velocity standardized to height (z score; restricted to participants ≤17 years) as a sensitivity analysis.

RESULTS

In total, 667 patients with a mean baseline eGFR of 27 ml/min per 1.73 m2 were included. Pulse wave velocity above the 95th percentile was observed in 124 (20%) patients at baseline. Absolute pulse wave velocity increased gradually over the median follow-up of 2.7 (interquartile range, 0.7-4.4) years, whereas pulse wave velocity z score remained relatively stable. Absolute pulse wave velocity over time associated with time; older age; higher mean arterial pressure, LDL cholesterol, and albuminuria; and lower ferritin. Pulse wave velocity z score (n=628) was associated with the same variables and additionally, with higher diastolic BP z score, lower height z score, younger age, and girls. Of 628 patients, 369 reached the composite end point of CKD progression (50% eGFR loss, eGFR <10 ml/min per 1.73 m2, or the start of KRT) during a median follow-up of 2.4 (interquartile range, 0.9-4.6) years. Pulse wave velocity z score did not associate with CKD progression by univariable or multivariable proportional hazard analysis correcting for the established predictors eGFR, proteinuria, and BP.

CONCLUSIONS

Pulse wave velocity is increased in children with CKD but does not associate with eGFR or CKD progression.

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.

Arterial stiffness and nocturnal hypertension in preterm children and adolescents

BACKGROUND AND OBJECTIVES

Preterm birth has been associated with increased risk for developing hypertension and other chronic diseases during childhood and adulthood. The aim of the current prospective case-control study was to investigate the associations of preterm birth with ambulatory blood pressure (BP) levels and arterial stiffness during childhood and adolescence.

METHODS

The study population included 52 children and adolescents born preterm and 26 healthy children born full term with similar age. The participants underwent ambulatory BP monitoring (ABPM) and assessment of carotid-femoral pulse wave velocity (PWV).

RESULTS

Preterm children presented higher night SBP z score values compared to controls, but did not differ in other ABPM parameters, office peripheral and central SBPs. Nocturnal hypertension was found in 78% (7/9) of ex-preterm children with ambulatory BP hypertension. Preterm birth was an independent predictor of PWV z score adjusted for heart rate. Estimated marginal means for PWV z score adjusted for age, sex, presence of kidney disease at birth, office BPs, night BPs, central SBP, and BMI z scores were significantly higher in preterm individuals compared to controls (0.703, 95% confidence interval [CI] 0.431-0.975 versus -0.19, 95% CI -0.574-0.536, respectively, P  = 0.027). Preterm children who were overweight presented the highest values of night SBP and PWV z score.

CONCLUSION

Preterm birth is associated with higher nocturnal BP and increased arterial stiffness in childhood and adolescence. Increased awareness for detection of hypertension and prevention of obesity in childhood could prevent future adverse cardiovascular outcomes in preterm individuals.

Ambulatory Blood Pressure Monitoring in Children and Adolescents: 2022 Update: A Scientific Statement From the American Heart Association

Use of ambulatory blood pressure monitoring in children and adolescents has markedly increased since publication of the last American Heart Association scientific statement on pediatric ambulatory blood pressure monitoring in 2014. In addition, there has also been significant expansion of the evidence base for use of ambulatory blood pressure monitoring in the pediatric population, including new data linking ambulatory blood pressure levels with the development of blood pressure-related target organ damage. Last, additional data have recently been published that enable simplification of the classification of pediatric ambulatory monitoring studies. This scientific statement presents a succinct review of this new evidence, guidance on optimal application of ambulatory blood pressure monitoring in the clinical setting, and an updated classification scheme for the interpretation of ambulatory blood pressure monitoring in children and adolescents. We also highlight areas of uncertainty where additional research is needed.

Isolated nocturnal hypertension in pediatric kidney transplant recipients

BACKGROUND

Isolated nocturnal hypertension (INH) is defined as nighttime hypertension in the setting of normal daytime blood pressure (BP), diagnosed by ambulatory BP monitoring (ABPM).

METHODS AND RESULTS

Hypertension affects 60%-80% of pediatric kidney transplant recipients, and INH is the most common type of ambulatory hypertension. INH is associated with an increased prevalence of hypertension-mediated target organ damage such as left ventricular hypertrophy in adults and in pediatric kidney transplant recipients.

CONCLUSION

Ambulatory BP monitoring should be performed annually in all pediatric kidney transplant recipients to diagnose hypertension phenotypes that are not detectable by office BP such as masked hypertension, white-coat hypertension, or INH. Isolated nocturnal hypertension in pediatric transplant patients requires study as a treatment target.

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.

Isolated Nocturnal Hypertension in Children

Isolated nocturnal hypertension (INH) is attracting attention because it has been shown to correlate with target organ damage as well as cardiovascular events in adults. INH has also been reported in children especially in those with underlying diseases including chronic kidney disease and some studies reported association with markers of early target organ damage. INH occupies the majority of nocturnal hypertension. On the other hand, masked hypertension is largely attributed to INH. INH is usually diagnosed by ambulatory blood pressure monitoring. Recently, it became possible to monitor sleep blood pressure by an automated home blood pressure device feasible also in children. The epidemiology, methodology and reproducibility, pathophysiology, relation to target organ damage, and treatment of INH in children will be reviewed here along with adult data.

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.

Hemodiafiltration maintains a sustained improvement in blood pressure compared to conventional hemodialysis in children-the HDF, heart and height (3H) study

BACKGROUND

Hypertension is prevalent in children on dialysis and associated with cardiovascular disease. We studied the blood pressure (BP) trends and the evolution of BP over 1 year in children on conventional hemodialysis (HD) vs. hemodiafiltration (HDF).

METHODS

This is a post hoc analysis of the "3H - HDF-Hearts-Height" dataset, a multicenter, parallel-arm observational study. Seventy-eight children on HD and 55 on HDF who had three 24-h ambulatory BP monitoring (ABPM) measures over 1 year were included. Mean arterial pressure (MAP) was calculated and hypertension defined as 24-h MAP standard deviation score (SDS) ≥95th percentile.

RESULTS

Poor agreement between pre-dialysis systolic BP-SDS and 24-h MAP was found (mean difference - 0.6; 95% limits of agreement -4.9-3.8). At baseline, 82% on HD and 44% on HDF were hypertensive, with uncontrolled hypertension in 88% vs. 25% respectively; p < 0.001. At 12 months, children on HDF had consistently lower MAP-SDS compared to those on HD (p < 0.001). Over 1-year follow-up, the HD group had mean MAP-SDS increase of +0.98 (95%CI 0.77-1.20; p < 0.0001), whereas the HDF group had a non-significant increase of +0.15 (95%CI -0.10-0.40; p = 0.23). Significant predictors of MAP-SDS were dialysis modality (β = +0.83 [95%CI +0.51 - +1.15] HD vs. HDF, p < 0.0001) and higher inter-dialytic-weight-gain (IDWG)% (β = 0.13 [95%CI 0.06-0.19]; p = 0.0003).

CONCLUSIONS

Children on HD had a significant and sustained increase in BP over 1 year compared to a stable BP in those on HDF, despite an equivalent dialysis dose. Higher IDWG% was associated with higher 24-h MAP-SDS in both groups.

Pathophysiology and consequences of arterial stiffness in children with chronic kidney disease

Changes in arterial structure and function are seen early in the course of chronic kidney disease (CKD) and have been causally associated with cardiovascular (CV) morbidity. Numerous potential injuries encompassing both traditional and uremia-specific CV risk factors can induce structural arterial changes and accelerate arterial stiffening. When the buffering capacity of the normally elastic arteries is reduced, damage to vulnerable microcirculatory beds can occur. Moreover, the resultant increase to cardiac afterload contributes to the development of left ventricular hypertrophy and cardiac dysfunction. Adult studies have linked arterial stiffness with increased risk of mortality, CV events, cognitive decline, and CKD progression. Pulse wave velocity (PWV) is currently the gold standard of arterial stiffness assessment but its measurement in children is challenging due to technical difficulties and physiologic aspects related to growth and poor standardization between algorithms for calculating PWV. Nevertheless, studies in pediatric CKD have reported increased arterial stiffness in children with advanced CKD, on dialysis, and after kidney transplantation. Development of arterial stiffness in children with CKD is closely related to mineral-bone disease and hypertension, but other factors may also play a significant role. The clinical relevance of accelerated arterial stiffness in childhood on cardiovascular outcomes in adult life remains unclear, and prospective studies are needed. In this review we discuss mechanisms leading to arterial stiffness in CKD and its clinical implications, along with issues surrounding the technical aspects of arterial stiffness assessment in children.

Could arterial stiffness be early reversible target organ damage test in childhood hypertension?

OBJECTIVE

The recommended treatment for hypertension (HTN) in children has been revised recently. This study aimed to present the changes in target organ damage (TOD) and arterial stiffness parameters after treatment in children with primary HTN who were managed in accordance with the 2016 European Society of Hypertension Guidelines.

METHODS

Patients with primary HTN included in this study were newly diagnosed, untreated, and were followed-up for a minimum of 6 months. HTN was confirmed by 24-h ambulatory blood pressure monitoring (ABPM). All patients underwent the following assessments: anthropometrical measurements of body mass index (BMI), carotid intima-media thickness (cIMT), left ventricular mass index (LVMI), plasma creatinine, urea, electrolytes, uric acid, fasting plasma glucose, blood lipids, urinalysis, urine culture, and first morning urine albumin tocreatinine ratio. The ABPM device performed measurements such as central blood pressure (cBP) and pulse wave velocity (PWV).

RESULTS

Thirty-two of 104 patients were enrolled. Seventeen patients were male, and 53% were obese. Compared with pretreatment, creatinine, urea, systolic BP (SBP), diastolic BP (DBP), systolic load, diastolic load, central SBP (cSBP), cSBP z score, cDBP, and PWV z score decreased, whereas LVMI and BMI z scores were unchanged.

CONCLUSION

After BP improvement, while LVMI did not regress, the cSBP, cSBP z, and PWV z score values, which are markers of arterial stiffness, regressed. This supports the corrective effect of BP control on the cardiovascular system even in a short-term follow-up. Further longitudinal studies are needed for the assessment of BP control on arterial stiffness in childhood.

Isolated nocturnal hypertension is associated with increased left ventricular mass index in children

BACKGROUND

Isolated nocturnal hypertension (INH) is associated with increased prevalence of left ventricular hypertrophy (LVH) and cardiovascular morbidity and mortality in adult patients. Unlike in adults, data illustrating the possible association between INH and cardiac target organ damage is lacking in children. This study aimed to investigate whether INH is associated with increased left ventricular mass index (LVMI) and LVH in children.

METHODS

Retrospective data from all untreated children with confirmed ambulatory hypertension (HT) in our center was reviewed. Ambulatory blood pressure monitoring (ABPM) and echocardiography were performed concurrently. Ambulatory normotensive children served as controls. LVH was defined as LVMI ≥ 95th percentile.

RESULTS

There were 102 ABPM studies; of these, 79 children had renal HT, and 23 had primary HT. Median age of children was 13.2 years (3.8-18.9). Nineteen children had INH, 9 children had isolated daytime HT, 54 had daytime and nighttime HT, and 20 were normotensive. The LVMI adjusted for age (patient's LVMI/95th percentile of the LVMI) was significantly higher in children with INH than in normotensive children (0.83 ± 0.03 vs. 0.74 ± 0.03, p = 0.03). Left ventricular hypertrophy was present in 11% of children with INH; this was not significantly higher than in normotensive children (0%, p = 0.23).

CONCLUSIONS

This study investigated the association between INH and cardiac structure in children with primary and renal HT and showed children with INH had higher LVMI adjusted for age than normotensive children and children with INH had similar LVMI adjusted for age to children with isolated daytime HT.

Nighttime Home Blood Pressure in Children: Association with Ambulatory Blood Pressure and Preclinical Organ Damage

[Figure: see text].

Cardiovascular disease in children with chronic kidney disease

PURPOSE OF REVIEW

Cardiovascular disease (CVD) is a significant cause of morbidity and mortality in children with chronic kidney disease (CKD). The cause of CVD in children with CKD is multifactorial and there are new and emerging data regarding prevalence and risk factors for CVD in this population.

RECENT FINDINGS

A number of recent publications from longitudinal cohort studies of children with CKD have greatly increased our knowledge about the prevalence and risk factors for CVD including hypertension, obesity and dyslipidaemia. Masked hypertension and isolated nocturnal hypertension both correlate with surrogate markers of CVD in children. Obesity and adiposity are associated with an increased risk of CVD. Markers other than BMI such as waist to height ratio and fat-free tissue to fat tissue ratio better correlate with the presence of CVD in children. Dyslipidaemia is extremely prevalent in the paediatric CKD population, but there is a lack of consensus on treatment. More data on the relationship between bone mineral disease and CVD continue to emerge including an association between hyperparathyroidism and isolated nocturnal hypertension.

SUMMARY

Children with CKD have multiple potentially modifiable risk factors for CVD. Research focused on CVD outcomes in children is needed.

Prevalence of isolated nocturnal hypertension according to 2018 European Society of Cardiology and European Society of Hypertension office blood pressure categories

OBJECTIVES

To estimate the prevalence of isolated nocturnal hypertension (INH) and its relationships with office blood pressure (BP) categories defined by 2018 ESC/ESH guidelines.

METHODS

We conducted a prospective cohort study in consecutive patients referred to perform an ambulatory blood pressure monitoring (ABPM) for diagnosis or therapeutic purposes. Office BP measurements and ABPM were performed in the same visit. The cohort was divided according to office BP in optimal, normal, high-normal and hypertension. The prevalence and adjusted risk for combined daytime and nocturnal hypertension and INH were estimated for each category.

RESULTS

We evaluated 1344 individuals, 59.3% women (51 ± 14 years old) and 40.7% men (52 ± 15 years old). 61.5% of the individuals had nocturnal hypertension, 12.9% INH and 48.7% combined daytime and nocturnal hypertension. Prevalence of combined daytime and nocturnal hypertension increased through office BP categories (P < 0.001). Conversely, prevalence of INH was lower in individuals with hypertension than in normotensives (7.4 vs. 17.2%, P < 0.001) and similar between nonhypertensive office BP categories, 16.6, 15 and 19.4% for optimal, normal and high-normal BP, respectively (P < 0.399). In individuals with office BP values less than 140/90 mmHg, the prevalence of masked hypertension phenotypes were 8.6, 17.2 and 30.2% for daytime, INH and combined daytime and nocturnal hypertension, respectively. Adjusted risk for combined daytime and nocturnal hypertension increased significantly through office BP categories; conversely, the risk for INH was similar in all nonhypertensive office BP categories.

CONCLUSION

Nocturnal hypertension was the more prevalent phenotype of masked hypertension and more than one-third of the individuals with nocturnal hypertension had INH. The risk for INH was not related to nonhypertensive office BP categories.

Factors influencing blood pressure and microalbuminuria in children with type 1 diabetes mellitus: salt or sugar?

BACKGROUND

The aim of the study is to identify the effect of salt intake and diabetes itself on blood pressure (BP) profile and microalbuminuria in children with type one diabetes mellitus (T1DM). Our hypothesis is that higher amount of salt consumption and/or hyperglycemia may impair blood pressure pattern in children with T1DM.

METHODS

This cross-sectional study included 84 children and adolescents with T1DM (62% females, age 13.9 ± 3.2 years, disease duration 7.3 ± 3.1 years, 43% poorly controlled diabetes) and 54 aged- and sex-matched healthy children with an adequately collected 24-h urine samples. Urine sodium, creatinine, and microalbumin were measured and salt intake was assessed on the basis of sodium excretion in 24-h urine. Blood pressure profile of the children with T1DM was evaluated with 24-h ambulatory blood pressure monitoring.

RESULTS

Compared to the children with well-controlled diabetes, children with poorly controlled diabetes had significantly higher standard deviation scores (SDS) of nighttime systolic BP (0.22 ± 1.28 vs - 0.87 ± 0.76, p = 0.003) and lower dipping in diastole (13.4 ± 5.9 vs 18.4 ± 8.1, p = 0.046). Among T1DM group, children with the highest quartile of salt intake had higher nighttime systolic and diastolic BP-SDS (0.53 ± 1.25 vs - 0.55 ± 0.73, p = 0.002 and 0.89 ± 1.19 vs 0.25 ± 0.63, p = 0.038, respectively) and lower dipping in systole compared to their counterparts (7.7 ± 5.0 vs 11.5 ± 6.1, p = 0.040). High averaged HbA1c was independently associated with higher both daytime and nighttime systolic BP-SDS (p = 0.010, p < 0.001) and nighttime diastolic BP-SDS (p = 0.001), and lower diastolic dipping (p = 0.001). High salt intake was independently associated with higher nighttime systolic BP-SDS (p = 0.002) and lower systolic dipping (p = 0.019). A 24-h MAP-SDS was the only independent risk factor for microalbuminuria (p = 0.035).

CONCLUSION

Beside poor diabetic control, high salt consumption appears to be an important modifiable risk factor for impaired BP pattern, which contributes to the development of diabetic kidney disease in children with T1DM.

Long-term complications of acute kidney injury in children

PURPOSE OF REVIEW

The current review will describe the current evidence and mechanisms of acute kidney injury (AKI) as a risk factor for long-term kidney complications, summarize the rationale for AKI follow-up and present an approach to monitoring children with AKI. Despite emerging evidence linking AKI with risk for long-term kidney and cardiovascular outcomes, many children who develop AKI are not followed for kidney disease development after hospital discharge. Better understanding of long-term complications after AKI and practical algorithms for follow-up will hopefully increase the rate and quality of post-AKI monitoring.

RECENT FINDINGS

Recent evidence shows that pediatric AKI is associated with long-term renal outcomes such as chronic kidney disease (CKD) and hypertension, both known to increase cardiovascular risk. The mechanism of AKI progression to CKD involves maladaptive regeneration of tubular epithelial and endothelial cells, inflammation, fibrosis and glomerulosclerosis. Many AKI survivors are not followed, and no guidelines for pediatric AKI follow-up have been published.

SUMMARY

Children who had AKI are at increased risk of long-term renal complications but many of them are not monitored for these complications. Recognizing long-term outcomes post-AKI and integration of follow-up programs may have a long-lasting positive impact on patient health.