Ambulatory Blood Pressure and Number of Subclinical Target Organ Injury Markers in Youth: The SHIP AHOY Study

Background

Hypertension in adolescence is associated with subclinical target organ injury (TOI). We aimed to determine whether different blood pressure (BP) thresholds were associated with increasing number of TOI markers in healthy adolescents.

Methods

244 participants (mean age 15.5±1.8 years, 60.1% male) were studied. Participants were divided based on both systolic clinic and ambulatory BP (ABP), into low- (<75 th percentile), mid- (75 th -90 th percentile) and high-risk (>90 th percentile) groups. TOI assessments included left ventricular mass, systolic and diastolic function, and vascular stiffness. The number of TOI markers for each participant was calculated. A multivariable general linear model was constructed to evaluate the association of different participant characteristics with higher numbers of TOI markers.

Results

47.5% of participants had at least one TOI marker: 31.2% had one, 11.9% two, 3.7% three, and 0.8% four. The number of TOI markers increased according to the BP risk groups: the percentage of participants with more than one TOI in the low-, mid-, and high groups based on clinic BP was 6.7%, 19.1%, and 21.8% (p=0.02), and based on ABP was 9.6%, 15.8%, and 32.2% (p<0.001). In a multivariable regression analysis, both clinic BP percentile and ambulatory SBP index were independently associated with the number of TOI markers. When both clinic and ABP were included in the model, only the ambulatory SBP index was significantly associated with the number of markers.

Conclusion

High SBP, especially when assessed by ABPM, was associated with an increasing number of subclinical cardiovascular injury markers in adolescents.

Blood Pressure Outcomes in NICU-Admitted Infants with Neonatal Hypertension: A Pediatric Nephrology Research Consortium Study

OBJECTIVE

To describe the blood pressure outcomes of infants admitted to the neonatal intensive care unit (NICU) with idiopathic (nonsecondary) hypertension (HTN) who were discharged on antihypertensive therapy.

STUDY DESIGN

Retrospective, multicenter study of 14 centers within the Pediatric Nephrology Research Consortium. We included all infants with a diagnosis of idiopathic HTN discharged from the NICU on antihypertensive treatment. The primary outcome was time to discontinuation of antihypertensive therapy, grouped into (≤6 months, >6 months to 1 year, and >1 year). Comparisons between groups were made with χ2 tests, Fisher's exact tests, and ANOVA.

RESULTS

Data from 118 infants (66% male) were included. Calcium channel blockers were the most prescribed class of antihypertensives (56%) in the cohort. The percentages remaining on antihypertensives after NICU discharge were 60% at 6 months, 26% at 1 year, and 7% at 2 years. Antenatal steroid treatment was associated with decreased likelihood of antihypertensive therapy >1 year after discharge.

CONCLUSIONS

This multicenter study reports that most infants admitted to the NICU diagnosed with idiopathic HTN will discontinue antihypertensive treatment by 2 years after NICU discharge. These data provide important insights into the outcome of neonatal HTN, but should be confirmed prospectively.

Evidence of increased vascular stiffness and left ventricular hypertrophy in children with cystic kidney disease

BACKGROUND

Cardiovascular disease (CVD) is the most common cause of mortality in chronic kidney disease (CKD). Children with early-onset CKD arguably experience the greatest lifetime CVD burden. We utilized data from the Chronic Kidney Disease in Children Cohort Study (CKiD) to evaluate two pediatric CKD cohorts: congenital anomalies of the kidney and urinary tract (CAKUT) and cystic kidney disease for CVD risks and outcomes.

METHODS

CVD risk factors and outcomes including blood pressures, left ventricular hypertrophy (LVH), left ventricular mass index (LVMI), and ambulatory arterial stiffness index (AASI) scores were evaluated.

RESULTS

Forty-one patients in the cystic kidney disease group were compared to 294 patients in the CAKUT group. Cystic kidney disease patients had higher cystatin-C levels, despite similar iGFR. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) indexes were higher in the CAKUT group, but a significantly higher proportion of cystic kidney disease patients was on anti-hypertensive medications. Cystic kidney disease patients had increased AASI scores and a higher incidence of LVH.

CONCLUSIONS

This study provides a nuanced analysis of CVD risk factors and outcomes including AASI and LVH in two pediatric CKD cohorts. Cystic kidney disease patients had increased AASI scores, higher incidence of LVH, and higher rates of anti-hypertensive medication use which could imply a greater burden of CVD despite similar GFR. Our work suggests that additional mechanisms may contribute to vascular dysfunction in cystic kidney disease, and that these patients may need additional interventions to prevent the development of CVD. A higher resolution version of the Graphical abstract is available as Supplementary information.

The Preserving Kidney Function in Children With CKD (PRESERVE) Study: Rationale, Design, and Methods

Rationale & Objective

PRESERVE seeks to provide new knowledge to inform shared decision-making regarding blood pressure (BP) management for pediatric chronic kidney disease (CKD). PRESERVE will compare the effectiveness of alternative strategies for monitoring and treating hypertension on preserving kidney function; expand the National Patient-Centered Clinical Research Network (PCORnet) common data model by adding pediatric- and kidney-specific variables and linking electronic health record data to other kidney disease databases; and assess the lived experiences of patients related to BP management.

Study Design

Multicenter retrospective cohort study (clinical outcomes) and cross-sectional study (patient-reported outcomes [PROs]).

Setting & Participants

PRESERVE will include approximately 20,000 children between January 2009-December 2022 with mild-moderate CKD from 15 health care institutions that participate in 6 PCORnet Clinical Research Networks (PEDSnet, STAR, GPC, PaTH, CAPRiCORN, and OneFlorida+). The inclusion criteria were ≥1 nephrologist visit and ≥2 estimated glomerular filtration rate (eGFR) values in the range of 30 to <90 mL/min/1.73 m2 separated by ≥90 days without an intervening value ≥90 mL/min/1.73 m2 and no prior dialysis or kidney transplant.

Exposures

BP measurements (clinic-based and 24-hour ambulatory BP); urine protein; and antihypertensive treatment by therapeutic class.

Outcomes

The primary outcome is a composite event of a 50% reduction in eGFR, eGFR of <15 mL/min/1.73 m2, long-term dialysis or kidney transplant. Secondary outcomes include change in eGFR, adverse events, and PROs.

Analytical Approach

Longitudinal models for dichotomous (proportional hazards or accelerated failure time) and continuous (generalized linear mixed models) clinical outcomes; multivariable linear regression for PROs. We will evaluate heterogeneity of treatment effect by CKD etiology and degree of proteinuria and will examine variation in hypertension management and outcomes based on socio-demographics.

Limitations

Causal inference limited by observational analyses.

Conclusions

PRESERVE will leverage the PCORnet infrastructure to conduct large-scale observational studies that address BP management knowledge gaps for pediatric CKD, focusing on outcomes that are meaningful to patients.

Plain-Language Summary

Hypertension is a major modifiable contributor to loss of kidney function in chronic kidney disease (CKD). The purpose of PRESERVE is to provide evidence to inform shared decision-making regarding blood pressure management for children with CKD. PRESERVE is a consortium of 16 health care institutions in PCORnet, the National Patient-Centered Clinical Research Network, and includes electronic health record data for >19,000 children with CKD. PRESERVE will (1) expand the PCORnet infrastructure for research in pediatric CKD by adding kidney-specific variables and linking electronic health record data to other kidney disease databases; (2) compare the effectiveness of alternative strategies for monitoring and treating hypertension on preserving kidney function; and (3) assess the lived experiences of patients and caregivers related to blood pressure management.

Clinical course and management of children with IgA vasculitis with nephritis

BACKGROUND

IgA vasculitis is the most common vasculitis in children and is often complicated by acute nephritis (IgAVN). Risk of chronic kidney disease (CKD) among children with IgAVN remains unknown. This study aimed to describe the clinical management and kidney outcomes in a large cohort of children with IgAVN.

METHODS

This observational cohort study used the PEDSnet database to identify children diagnosed with IgAV between January 1, 2009, and February 29, 2020. Demographic and clinical characteristics were compared among children with and without kidney involvement. For children followed by nephrology, clinical course, and management patterns were described. Patients were divided into four categories based on treatment: observation, renin-angiotensin-aldosterone system (RAAS) blockade, corticosteroids, and other immunosuppression, and outcomes were compared among these groups.

RESULTS

A total of 6802 children had a diagnosis of IgAV, of whom 1139 (16.7%) were followed by nephrology for at least 2 visits over a median follow-up period of 1.7 years [0.4,4.2]. Conservative management was the most predominant practice pattern, consisting of observation in 57% and RAAS blockade in 6%. Steroid monotherapy was used in 29% and other immunosuppression regimens in 8%. Children receiving immunosuppression had higher rates of proteinuria and hypertension compared to those managed with observation (p < 0.001). At the end of follow-up, 2.6 and 0.5% developed CKD and kidney failure, respectively.

CONCLUSIONS

Kidney outcomes over a limited follow-up period were favorable in a large cohort of children with IgAV. Immunosuppressive medications were used in those with more severe presentations and may have contributed to improved outcomes. A higher resolution version of the Graphical abstract is available as Supplementary information.

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.

Risk of Target Organ Damage in Children With Primary Ambulatory Hypertension: A Systematic Review and Meta-Analysis

BACKGROUND

Target organ damage (TOD) such as left ventricular hypertrophy (LVH), abnormal pulse wave velocity, and elevated carotid intima-media thickness are common among adults with hypertension and are associated with overt cardiovascular events. The risk of TOD among children and adolescents with hypertension confirmed by ambulatory blood pressure monitoring is poorly understood. In this systematic review, we compare the risks of TOD among children and adolescents with ambulatory hypertension to normotensive individuals.

METHODS

A literature search was conducted to include all relevant English-language publications from January 1974 to March 2021. Studies were included if patients underwent 24-hour ambulatory blood pressure monitoring and ≥1 TOD was reported. Ambulatory hypertension was defined by society guidelines. Primary outcome was the risk of TOD, including LVH, left ventricular mass index, pulse wave velocity, and carotid intima-media thickness among children with ambulatory hypertension compared with those with ambulatory normotension. Meta-regression calculated the effect of body mass index on TOD.

RESULTS

Of 12 252 studies, 38 (n=3609 individuals) were included for analysis. Children with ambulatory hypertension had an increased risk of LVH (odds ratio, 4.69 [95% CI, 2.69-8.19]), elevated left ventricular mass index (pooled difference, 5.13 g/m^2.7; [95% CI, 3.78-6.49]), elevated pulse wave velocity (pooled difference, 0.39 m/s [95% CI, 0.20-0.58]), and elevated carotid intima-media thickness (pooled difference, 0.04 mm [95% CI, 0.02-0.05]), compared with normotensive children. Meta-regression showed a significant positive effect of body mass index on left ventricular mass index and carotid intima-media thickness.

CONCLUSIONS

Children with ambulatory hypertension have adverse TOD profiles, which may increase their risk for future cardiovascular disease. This review highlights the importance of optimizing blood pressure control and screening for TOD in children with ambulatory hypertension.

REGISTRATION

URL: https://www.crd.york.ac.uk/PROSPERO/; Unique identifier: CRD42020189359.

Evaluating Kidney Function Decline in Children with Chronic Kidney Disease Using a Multi-Institutional Electronic Health Record Database

BACKGROUND

The objectives of this study were to use electronic health record data from a US national multicenter pediatric network to identify a large cohort of children with CKD, evaluate CKD progression, and examine clinical risk factors for kidney function decline.

METHODS

This retrospective cohort study identified children seen between January 1, 2009, to February 28, 2022. Data were from six pediatric health systems in PEDSnet. We identified children aged 18 months to 18 years who met criteria for CKD: two eGFR values <90 and ≥15 ml/min per 1.73 m2 separated by ≥90 days without an intervening value ≥90. CKD progression was defined as a composite outcome: eGFR <15 ml/min per 1.73 m2, ≥50% eGFR decline, long-term dialysis, or kidney transplant. Subcohorts were defined based on CKD etiology: glomerular, nonglomerular, or malignancy. We assessed the association of hypertension (≥2 visits with hypertension diagnosis code) and proteinuria (≥1 urinalysis with ≥1+ protein) within 2 years of cohort entrance on the composite outcome.

RESULTS

Among 7,148,875 children, we identified 11,240 (15.7 per 10,000) with CKD (median age 11 years, 50% female). The median follow-up was 5.1 (interquartile range 2.8-8.3) years, the median initial eGFR was 75.3 (interquartile range 61-83) ml/min per 1.73 m2, 37% had proteinuria, and 35% had hypertension. The following were associated with CKD progression: lower eGFR category (adjusted hazard ratio [aHR] 1.44 [95% confidence interval (95% CI), 1.23 to 1.69], aHR 2.38 [95% CI, 2.02 to 2.79], aHR 5.75 [95% CI, 5.05 to 6.55] for eGFR 45-59 ml/min per 1.73 m2, 30-44 ml/min per 1.73 m2, 15-29 ml/min per 1.73 m2 at cohort entrance, respectively, when compared with eGFR 60-89 ml/min per 1.73 m2), glomerular disease (aHR 2.01 [95% CI, 1.78 to 2.28]), malignancy (aHR 1.79 [95% CI, 1.52 to 2.11]), proteinuria (aHR 2.23 [95% CI, 1.89 to 2.62]), hypertension (aHR 1.49 [95% CI, 1.22 to 1.82]), proteinuria and hypertension together (aHR 3.98 [95% CI, 3.40 to 4.68]), count of complex chronic comorbidities (aHR 1.07 [95% CI, 1.05 to 1.10] per additional comorbid body system), male sex (aHR 1.16 [95% CI, 1.05 to 1.28]), and younger age at cohort entrance (aHR 0.95 [95% CI, 0.94 to 0.96] per year older).

CONCLUSIONS

In large-scale real-world data for children with CKD, disease etiology, albuminuria, hypertension, age, male sex, lower eGFR, and greater medical complexity at start of follow-up were associated with more rapid decline in kidney function.

Skeletal Outcomes in Children and Young Adults with Glomerular Disease

BACKGROUND

Children with glomerular disease have unique risk factors for compromised bone health. Studies addressing skeletal complications in this population are lacking.

METHODS

This retrospective cohort study utilized data from PEDSnet, a national network of pediatric health systems with standardized electronic health record data for more than 6.5 million patients from 2009 to 2021. Incidence rates (per 10,000 person-years) of fracture, slipped capital femoral epiphysis (SCFE), and avascular necrosis/osteonecrosis (AVN) in 4598 children and young adults with glomerular disease were compared with those among 553,624 general pediatric patients using Poisson regression analysis. The glomerular disease cohort was identified using a published computable phenotype. Inclusion criteria for the general pediatric cohort were two or more primary care visits 1 year or more apart between 1 and 21 years of age, one visit or more every 18 months if followed >3 years, and no chronic progressive conditions defined by the Pediatric Medical Complexity Algorithm. Fracture, SCFE, and AVN were identified using SNOMED-CT diagnosis codes; fracture required an associated x-ray or splinting/casting procedure within 48 hours.

RESULTS

We found a higher risk of fracture for the glomerular disease cohort compared with the general pediatric cohort in girls only (incidence rate ratio [IRR], 1.6; 95% CI, 1.3 to 1.9). Hip/femur and vertebral fracture risk were increased in the glomerular disease cohort: adjusted IRR was 2.2 (95% CI, 1.3 to 3.7) and 5 (95% CI, 3.2 to 7.6), respectively. For SCFE, the adjusted IRR was 3.4 (95% CI, 1.9 to 5.9). For AVN, the adjusted IRR was 56.2 (95% CI, 40.7 to 77.5).

CONCLUSIONS

Children and young adults with glomerular disease have significantly higher burden of skeletal complications than the general pediatric population.

Association of Blood Pressure-Related Increase in Vascular Stiffness on Other Measures of Target Organ Damage in Youth

BACKGROUND

Hypertension-related increased arterial stiffness predicts development of target organ damage (TOD) and cardiovascular disease. We hypothesized that blood pressure (BP)-related increased arterial stiffness is present in youth with elevated BP and is associated with TOD.

METHODS

Participants were stratified by systolic BP into low- (systolic BP <75th percentile, n=155), mid- (systolic BP ≥80th and <90th percentile, n=88), and high-risk BP categories (≥90th percentile, n=139), based on age-, sex- and height-specific pediatric BP cut points. Clinic BP, 24-hour ambulatory BP monitoring, anthropometrics, and laboratory data were obtained. Arterial stiffness measures included carotid-femoral pulse wave velocity and aortic stiffness. Left ventricular mass index, left ventricular systolic and diastolic function, and urine albumin/creatinine were collected. ANOVA with Bonferroni correction was used to evaluate differences in cardiovascular risk factors, pulse wave velocity, and cardiac function across groups. General linear models were used to examine factors associated with arterial stiffness and to determine whether arterial stiffness is associated with TOD after accounting for BP.

RESULTS

Pulse wave velocity increased across groups. Aortic distensibility, distensibility coefficient, and compliance were greater in low than in the mid or high group. Significant determinants of arterial stiffness were sex, age, adiposity, BP, and LDL (low-density lipoprotein) cholesterol. Pulse wave velocity and aortic compliance were significantly associated with TOD (systolic and diastolic cardiac function and urine albumin/creatinine ratio) after controlling for BP.

CONCLUSIONS

Higher arterial stiffness is associated with elevated BP and TOD in youth emphasizing the need for primary prevention of cardiovascular disease.

Cardiovascular Risk Factors and Target Organ Damage in Adolescents: The SHIP AHOY Study

BACKGROUND

Development of cardiovascular disease in adults has been directly linked to an adverse metabolic phenotype. While there is evidence that development of these risk factors in childhood persists into adulthood and the development of cardiovascular disease, less is known about whether these risk factors are associated with target organ damage during adolescence.

METHODS

We collected data from 379 adolescents (mean age 15.5, 60% male) with blood pressure between the 75th and 95th percentile to determine if there is a metabolic phenotype that predicts cardiovascular changes (left ventricular mass, systolic and diastolic function, pulse wave velocity, and renal function). We determined the number of risk factors for cardiovascular disease (hypertension, dyslipidemia, obesity, and insulin resistance) present in each participant. Generalized linear models were constructed to determine if the number of cardiovascular risk factors (CVRFs) were associated with measures of target organ damage.

RESULTS

The number of CVRFs present were associated with statistically significant differences in increased left ventricular mass index, increased pulse wave velocity, decreased peak longitudinal strain, urine albumin to creatine ratio and echocardiographic parameters of diastolic dysfunction. Generalized linear models showed that dyslipidemia and insulin resistance were independently associated with markers of diastolic dysfunction (P ≤ .05) while increased blood pressure was associated with all makers of target organ damage (P ≤ .03).

CONCLUSIONS

These data suggest the of the number of CVRFs present is independently associated with early changes in markers of target organ damage during adolescence.

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.

Using a Multi-Institutional Pediatric Learning Health System to Identify Systemic Lupus Erythematosus and Lupus Nephritis: Development and Validation of Computable Phenotypes

BACKGROUND AND OBJECTIVES

Performing adequately powered clinical trials in pediatric diseases, such as SLE, is challenging. Improved recruitment strategies are needed for identifying patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Electronic health record algorithms were developed and tested to identify children with SLE both with and without lupus nephritis. We used single-center electronic health record data to develop computable phenotypes composed of diagnosis, medication, procedure, and utilization codes. These were evaluated iteratively against a manually assembled database of patients with SLE. The highest-performing phenotypes were then evaluated across institutions in PEDSnet, a national health care systems network of >6.7 million children. Reviewers blinded to case status used standardized forms to review random samples of cases (n=350) and noncases (n=350).

RESULTS

Final algorithms consisted of both utilization and diagnostic criteria. For both, utilization criteria included two or more in-person visits with nephrology or rheumatology and ≥60 days follow-up. SLE diagnostic criteria included absence of neonatal lupus, one or more hydroxychloroquine exposures, and either three or more qualifying diagnosis codes separated by ≥30 days or one or more diagnosis codes and one or more kidney biopsy procedure codes. Sensitivity was 100% (95% confidence interval [95% CI], 99 to 100), specificity was 92% (95% CI, 88 to 94), positive predictive value was 91% (95% CI, 87 to 94), and negative predictive value was 100% (95% CI, 99 to 100). Lupus nephritis diagnostic criteria included either three or more qualifying lupus nephritis diagnosis codes (or SLE codes on the same day as glomerular/kidney codes) separated by ≥30 days or one or more SLE diagnosis codes and one or more kidney biopsy procedure codes. Sensitivity was 90% (95% CI, 85 to 94), specificity was 93% (95% CI, 89 to 97), positive predictive value was 94% (95% CI, 89 to 97), and negative predictive value was 90% (95% CI, 84 to 94). Algorithms identified 1508 children with SLE at PEDSnet institutions (537 with lupus nephritis), 809 of whom were seen in the past 12 months.

CONCLUSIONS

Electronic health record-based algorithms for SLE and lupus nephritis demonstrated excellent classification accuracy across PEDSnet institutions.

Pediatric Ambulatory Blood Pressure Classification: The Case for a Change

In 1997, Soergel et al¹ published the first set of normative values for ambulatory blood pressure monitoring (ABPM) in children. Since then, the clinical utility of ABPM has increased dramatically, and now, ABPM is accepted as the standard method to confirm the diagnosis of hypertension in children. Despite significant progress in the field of pediatric ABPM, many important questions remain unanswered. One of the most controversial issues is how to define ambulatory hypertension in children. The purpose of this review is to discuss the limitations of the current pediatric ABPM classification scheme and to provide the justification and rationale for a new classification.

Recovery of kidney function after dialysis initiation in children and adults in the US: A retrospective study of United States Renal Data System data

BACKGROUND

Little is known about factors associated with recovery of kidney function-and return to dialysis independence-or temporal trends in recovery after starting outpatient dialysis in the United States. Understanding the characteristics of individuals who may have the potential to recover kidney function may promote better recognition of such events. The goal of this study was to determine factors associated with recovery of kidney function in children compared with adults starting dialysis in the US.

METHODS AND FINDINGS

We determined factors associated with recovery of kidney function-defined as survival and discontinuation of dialysis for ≥90-day period-in children versus adults who started maintenance dialysis between 1996 and 2015 according to the United States Renal Data System (USRDS) followed through 2016 in a retrospective cohort study. We also examined temporal trends in recovery rates over the last 2 decades in this cohort. Among 1,968,253 individuals included for study, the mean age was 62.6 ± 15.8 years, and 44% were female. Overall, 4% of adults (83,302/1,953,881) and 4% of children (547/14,372) starting dialysis in the outpatient setting recovered kidney function within 1 year. Among those who recovered, the median time to recovery was 73 days (interquartile range [IQR] 43-131) in adults and 100 days (IQR 56-189) in children. Accounting for the competing risk of death, children were less likely to recover kidney function compared with adults (sub-hazard ratio [sub-HR] 0.81; 95% CI 0.74-0.89, p-value <0.001; point estimates <1 indicating increased risk for a negative outcome). Non-Hispanic black (NHB) adults were less likely to recover compared with non-Hispanic white (NHW) adults, but these racial differences were not observed in children. Of note, a steady increase in the incidence of recovery of kidney function was noted initially in adults and children between 1996 and 2010, but this trend declined thereafter. The diagnoses associated with the highest recovery rates of recovery were acute tubular necrosis (ATN) and acute interstitial nephritis (AIN) in both adults and children, where 25%-40% of patients recovered kidney function depending on the calendar year of dialysis initiation. Limitations to our study include the potential for residual confounding to be present given the observational nature of our data.

CONCLUSIONS

In this study, we observed that discontinuation of outpatient dialysis due to recovery occurred in 4% of patients with end-stage kidney disease (ESKD) and was more common among those with ATN or AIN as the cause of their kidney disease. While recovery rates rose initially, they declined starting in 2010. Additional studies are needed to understand how to best recognize and promote recovery in patients whose potential to discontinue dialysis is high in the outpatient setting.

Social Determinants of Cardiovascular Health in African American Children With CKD: An Analysis of the Chronic Kidney Disease in Children (CKiD) Study

RATIONALE & OBJECTIVE

To identify differences in socioeconomic factors (SES) and subclinical cardiovascular disease (CVD) markers by race among Chronic Kidney Disease in Children (CKiD) participants and determine whether differences in CVD markers persist after adjusting for SES.

STUDY DESIGN

Analysis of 3,103 visits with repeated measures from 628 children (497 White participants; 131 African American participants) enrolled in the CKiD study.

SETTING & PARTICIPANTS

Children with mild-moderate CKD with at least 1 cardiovascular (CV) parameter (ambulatory blood pressure, left ventricular mass index [LVMI], or lipid profile) measured.

EXPOSURE

African American race.

OUTCOMES

Ambulatory hypertension, LVMI, triglycerides, high-density lipoprotein cholesterol.

ANALYTICAL APPROACH

Due to increased CV risks of glomerular disease, the analysis was stratified by CKD cause. Inverse probability weighting was used to adjust for SES (health insurance, household income, maternal education, food insecurity, abnormal birth history). Linear and logistic regression were used to evaluate association of race with CV markers.

RESULTS

African American children were disproportionately affected by adverse SES. African Americans with nonglomerular CKD had more instances of ambulatory hypertension and higher LVMI but more favorable lipid profiles. After adjustment for SES, age, and sex, the magnitude of differences in these CV markers was attenuated but remained statistically significant. Only LVMI differed by race in the glomerular CKD group, despite adjustment for SES.

LIMITATIONS

Study design limits causal inference.

CONCLUSION

African American children with CKD are disproportionately affected by socioeconomic disadvantages compared with White children. The degree to which CV markers differ by race is influenced by disease etiology. African Americans with nonglomerular CKD have increased LVMI, more ambulatory hypertension, and favorable lipid profile, but attenuation in magnitude after adjustment for SES was observed. African Americans with glomerular CKD had increased LVMI, which persisted after SES adjustment. As many social determinants of health were not captured, future research should examine effects of systemic racism on CV health in this population.

Correction to: Aortic dilatation in children with mild to moderate chronic kidney disease

The original version of this article unfortunately contained a mistake.

Abstract 6: Comparison Between Ambulatory BP Percentile And Load As Predictors Of Target Organ Damage In Youth

Ambulatory BP (ABP) is increasingly used to confirm the diagnosis of hypertension. Pediatric but not adult guidelines consider BP load (% readings above 95 th %ile) in risk-stratification of the ABP phenotype. We compared ABP sex- and height- specific percentile and BP load as predictors of left ventricular hypertrophy (LVH) in youth. We measured casual BP, ABP, anthropometrics, and calculated LV mass by echo as (g)/height (m) 2.7 (LVMI) in 357 adolescents (mean age 15.5 + 1.7 years, 63% white, 59% male). ABPM was performed with the Ontrak device (Spacelabs Inc., Snoqualmie, WA). ABP index was defined as mean ABP/sex- and height-specific 95 th %ile. LVH was defined as LVMI ≥38.6 (pediatric cut-point). Logistic regression was used to assess different ABP measures as predictors of LVH. Sensitivity and specificity of different ABP cut points as predictors of LVH were calculated. Seventy (19.6%) participants had LVH. Systolic 24-hour, wake and sleep ABP indices as well as 24-hour SBP load were all significantly associated with LVH, while wake and sleep SBP load were not. When adjusted for BMI percentile and sex, only the associations between ABP indices and LVH remained statistically significant (table). SBP percentiles also had better balanced sensitivities and specificities in predicting LVH (24-hour 65 th percentile: 63% and 59%; wake 70 th percentile: 54% and 62%; sleep 75 th percentile: 60% and 61%). There was no significant association between diastolic BP measures and LVH. We conclude that there is no significant contribution of BP load in predicting LVH in youth. Systolic ABP percentiles lower than the commonly used 95 th percentile are the best predictors of LVH in this population.

Adiposity, Sex, and Cardiovascular Disease Risk in Children With CKD: A Longitudinal Study of Youth Enrolled in the Chronic Kidney Disease in Children (CKiD) Study

RATIONALE & OBJECTIVE

Traditional and nontraditional cardiovascular disease risk factors are highly prevalent in children with chronic kidney disease (CKD). We examined the longitudinal association of adiposity with cardiac damage among children with CKD and explored whether this association was modified by sex.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Children with mild-to-moderate CKD enrolled in the Chronic Kidney Disease in Children (CKiD) Study at 49 pediatric nephrology centers across North America.

EXPOSURE

Age- and sex-specific body mass index (BMI) z score.

OUTCOME

Age- and sex-specific left ventricular mass index (LVMI) z score and left ventricular hypertrophy (LVH).

ANALYTICAL APPROACH

Longitudinal analyses using mixed-effects models to estimate sex-specific associations of BMI z scores with LVMI z score and with LVH, accounting for repeated measurements over time.

RESULTS

Among 725 children with 2,829 person-years of follow-up, median age was 11.0 years and median estimated glomerular filtration rate was 52.6mL/min/1.73m2. Nearly one-third of both boys and girls were overweight or obese, median LVMI z score was 0.18 (IQR: -0.67, 1.08), and 11% had LVH. Greater BMI z scores were independently associated with greater LVMI z scores and greater odds of LVH. For each 1-unit higher BMI z score, LVMI z score was 0.24 (95% CI, 0.17-0.31) higher in boys and 0.38 (95% CI, 0.29-0.47) higher in girls (Pinteraction = 0.01). For each 1-unit higher BMI z score, the odds of LVH was 1.5-fold (95% CI, 1.1-2.1) higher in boys and 3.1-fold (95% CI, 1.8-4.4) higher in girls (Pinteraction = 0.005).

LIMITATIONS

Not all children had repeated measurements. LVH is a surrogate and not a hard cardiac outcome. The observational design limits causal inference.

CONCLUSIONS

In children, adiposity is independently associated with the markers of cardiac damage, LVMI z score and LVH. This association is stronger among girls than boys. Pediatric overweight and obesity may therefore have a substantial impact on cardiovascular risk among children with CKD.

Subclinical Systolic and Diastolic Dysfunction Is Evident in Youth With Elevated Blood Pressure

Hypertension is associated with cardiovascular events in adults. Subclinical changes to left ventricular strain and diastolic function have been found before development of decreased left ventricular ejection fraction and cardiovascular events. Our objective was to study effects of blood pressure (BP) on ventricular function in youth across the BP spectrum. Vital signs and labs were obtained in 346 participants aged 11 to 19 years who had BP categorized as low-risk (N=144; systolic BP <75th percentile), mid-risk (N=83; systolic BP ≥80th and <90th percentile), and high-risk (N=119; systolic BP ≥90th percentile). Echocardiography was performed to assess left ventricular strain and diastolic function. Differences between groups were analyzed by ANOVA. General linear models were constructed to determine independent predictors of systolic and diastolic function. Mid-risk and high-risk participants had greater adiposity and more adverse metabolic labs (lower HDL [high-density lipoprotein], higher glucose, and higher insulin) than the low-risk group. Mid-risk and high-risk participants had significantly lower left ventricular ejection fraction and peak global longitudinal strain than the low-risk group (both P≤0.05). The E/e' ratio was higher in the high-risk group versus the low-risk and mid-risk groups, and the e'/a' ratio was lower in the high-risk versus the low-risk group (both P≤0.05). BP and adiposity were statistically significant determinants of left ventricular systolic and diastolic function. Subclinical changes in left ventricular systolic and diastolic function can be detected even at BP levels below the hypertensive range as currently defined.

Effect of Surgical Versus Medical Therapy on Diabetic Kidney Disease Over 5 Years in Severely Obese Adolescents With Type 2 Diabetes

OBJECTIVE

To compare diabetic kidney disease (DKD) rates over 5 years of follow-up in two cohorts of severely obese adolescents with type 2 diabetes (T2D) undergoing medical or surgical treatment for T2D.

RESEARCH DESIGN AND METHODS

A secondary analysis was performed of data collected from obese participants of similar age and racial distribution enrolled in the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) and the Treatment Options of Type 2 Diabetes in Adolescents and Youth (TODAY) studies. Teen-LABS participants underwent metabolic bariatric surgery (MBS). TODAY participants were randomized to metformin alone or in combination with rosiglitazone or intensive lifestyle intervention, with insulin therapy given for glycemic progression. Glycemic control, BMI, estimated glomerular filtration rate (eGFR), urinary albumin excretion (UAE), and prevalence of hyperfiltration (eGFR ≥135 mL/min/1.73 m²) and elevated UAE (≥30 mg/g) were assessed annually.

RESULTS

Participants with T2D from Teen-LABS (n = 30, mean ± SD age, 16.9 ± 1.3 years; 70% female; 60% white; BMI 54.4 ± 9.5 kg/m²) and TODAY (n = 63, age 15.3 ± 1.3 years; 56% female; 71% white; BMI 40.5 ± 4.9 kg/m²) were compared. During 5 years of follow-up, hyperfiltration decreased from 21% to 18% in Teen-LABS and increased from 7% to 48% in TODAY. Elevated UAE decreased from 27% to 5% in Teen-LABS and increased from 21% to 43% in TODAY. Adjusting for baseline age, sex, BMI, and HbA_1c, TODAY participants had a greater odds of hyperfiltration (odds ratio 15.7 [95% CI 2.6, 94.3]) and elevated UAE (27.3 [4.9, 149.9]) at 5 years of follow-up.

CONCLUSIONS

Compared with MBS, medical treatment of obese youth with T2D was associated with a higher odds of DKD over 5 years.

Hypertensive crisis in children and adolescents

Hypertensive crisis is a relatively rare condition in children. However, if not treated, it might be life-threatening and lead to irreversible damage of vital organs. Clinical presentation of patients with hypertensive crisis can vary from very mild (hypertensive urgency) to severe symptoms (hypertensive emergency) despite similarly high blood pressure (BP). Individualized assessment of patients presenting with high BP with emphasis on the evaluation of end-organ damage rather than on the specific BP number is a key in guiding physician's initial management of a hypertensive crisis. The main aim of the treatment of hypertensive crisis is the prevention or treatment of life-threatening complications of hypertension-induced organ dysfunction, including neurologic, ophthalmologic, renal, and cardiac complications. While the treatment strategy must be directed toward the immediate reduction of BP to reduce the hypertensive damage to these organs, it should not be at a too fast rate to cause hypoperfusion of vital organs by an excessively rapid reduction of BP. Thus, intravenous continuous infusions rather than intravenous boluses of antihypertensive medications should be the preferable mode of initial treatment of children with hypertensive emergency.

Association of Blood Pressure Level With Left Ventricular Mass in Adolescents

Hypertension is associated with left ventricular hypertrophy (LVH), a risk factor for cardiovascular events. Since cardiovascular events in youth are rare, hypertension has historically been defined by the 95th percentile of the normal blood pressure (BP) distribution in healthy children. The optimal BP percentile associated with LVH in youth is unknown. We aimed to determine the association of systolic BP (SBP) percentile, independent of obesity, on left ventricular mass index (LVMI), and to estimate which SBP percentile best predicts LVH in youth. We evaluated SBP, anthropometrics, and echocardiogram in 303 adolescents (mean age 15.6 years, 63% white, 55% male) classified by SBP as low-risk (L=141, <80th percentile), mid-risk (M=71, 80-<90th percentile), or high-risk (H=91, ≥90th percentile) using the mean of 6 measurements at 2 visits according to the 2017 guidelines. Logistic regression was used to determine the sensitivity and specificity of various SBP percentiles associated with LVH. Results: BP groups did not differ by age or demographics but differed slightly by body mass index. Mean BP, LVMI, and prevalence of LVH increased across groups (BP: L=111/75, M=125/82, and H=133/92 mm Hg; LVMI: L=31.2, M=34.2, and H=34.9 g/m^2.7; LVH: L=13%, M=21%, H=27%, all P<0.03). SBP percentile remained a significant determinant of LVMI after adjusting for covariates. The 90th percentile for SBP resulted in the best balance between sensitivity and specificity for predicting LVH (LVMI≥38.6 g/m^2.7). Abnormalities in cardiac structure in youth can be found at BP levels below those used to define hypertension.

Cardiovascular Disease in Children and Adolescents With Chronic Kidney Disease

The lifespan of children with advanced chronic kidney disease (CKD), although improved over the past 2 decades, remains low compared with the general pediatric population. Similar to adults with CKD, cardiovascular disease accounts for a majority of deaths in children with CKD because these patients have a high prevalence of traditional and uremia-related risk factors for cardiovascular disease. The cardiovascular alterations that cause these terminal events begin early in pediatric CKD. Initially, these act to maintain hemodynamic homeostasis. However, as the disease progresses, these modifications are unable to sustain cardiovascular function in the long term, leading to left ventricular failure, depressed cardiorespiratory fitness, and sudden death. In this review, we discuss the prevalence of the risk factors associated with cardiovascular disease in pediatric patients with CKD, the pathophysiology that stimulates these changes, the cardiac and vascular adaptations that occur in these patients, and management of the cardiovascular risk in these patients.

Prediction of Ambulatory Hypertension Based on Clinic Blood Pressure Percentile in Adolescents

Ambulatory blood pressure (BP) monitoring provides a more precise measure of BP status than clinic BP and is currently recommended in the evaluation of high BP in children and adolescents. However, ambulatory BP monitoring may not always be available. Our aim was to determine the clinic BP percentile most likely to predict ambulatory hypertension. We evaluated clinic and ambulatory BP in 247 adolescents (median age, 15.7 years; 63% white; 54% male). Clinic BP percentile (based on the fourth report and the 2017 American Academy of Pediatrics clinical practice guidelines) and ambulatory BP status (normal versus hypertension) were determined by age-, sex-, and height-specific cut points. Sensitivity and specificity of different clinic BP percentiles and cutoffs to predict ambulatory hypertension were calculated. Forty (16%) and 67 (27%) patients had systolic hypertension based on the fourth report and the 2017 guidelines, respectively, whereas 38 (15%) had wake ambulatory systolic hypertension. The prevalence of ambulatory wake systolic hypertension increased across clinic systolic BP percentiles, from 3% when clinic systolic BP was <50th percentile to 41% when ≥95th percentile. The 2017 guidelines' 85th systolic percentile had similar sensitivity (86.8%) and better specificity (57.4% versus 48.1%) than elevated BP (≥90th percentile or ≥120 mm Hg) to diagnose ambulatory hypertension. When evaluating adolescents for hypertension, 2017 guidelines' clinic systolic 85th percentile may be the optimal threshold at which to perform ambulatory BP monitoring.

SHIP-AHOY (Study of High Blood Pressure in Pediatrics: Adult Hypertension Onset in Youth)

Although hypertension is identifiable in children and adolescents, there are many knowledge gaps on how to best define and manage high blood pressure in the young. SHIP-AHOY (Study of High Blood Pressure in Pediatrics: Adult Hypertension Onset in Youth) is being conducted to address these knowledge gaps. Five hundred adolescents will be recruited and will undergo ambulatory blood pressure monitoring, echocardiographic, vascular, and cognitive assessments, as well as epigenetic studies to identify mechanisms that underlie the development of hypertensive target organ damage. Details of the design and methods that will be utilized in SHIP-AHOY are presented here, as well as baseline characteristics of the first 264 study participants. The primary aim of the study is to develop a risk-based definition of hypertension in the young that will result in better understanding of the transition from blood pressure in youth to adult cardiovascular disease.

Childhood Obesity and the Metabolic Syndrome

Obesity is a leading cause of chronic kidney disease. Children with severe obesity have an increased prevalence of early kidney abnormalities and are at high risk to develop kidney failure in adulthood. The pathophysiology of obesity-related kidney disease is incompletely understood, although the postulated mechanisms of kidney injury include hyperfiltration, adipokine dysregulation, and lipotoxic injury. An improved understanding of the long-term effects of obesity on kidney health is essential treat the growing epidemic of obesity-related kidney disease. The purpose of this article is to review the epidemiology, pathophysiology, clinical features, and management of obesity-related kidney disease in children and adolescents.

Abstract P393: Sex Modifies the Longitudinal Association of Adiposity With Left Ventricular Hypertrophy Among Children With Chronic Kidney Disease

Objective: Adiposity, not blood pressure (BP), is associated with left ventricular hypertrophy (LVH) among hypertensive children without chronic kidney disease (CKD). We aimed to determine the longitudinal association of BMI z-score with LVH and left ventricular mass index (LVMI) among children with CKD.

Methods: 696 participants of the Chronic Kidney Disease in Children study with echocardiography results who contributed a total of 1,300 visits were included. Mixed models, adjusting for repeated visits with a random subject effect, were used to determine the longitudinal association of body mass index (BMI) z-score with LVMI and LVH (LVMI> age-sex specific 95 th %ile). Models were adjusted for age, sex, race, systolic and diastolic BP z-score, glomerular diagnosis, time with CKD, glomerular filtration rate and calcium*phosphorus product and accounted for informative censoring.

Results: Baseline characteristics are in the table. Among females, a 1 unit increase in BMI z-score was associated with an 8.5% increase in LVMI and 3.4 greater odds of LVH, whereas with boys, a 1 unit increase in BMI z-score was associated with a 5.2% increase in LVMI and a 1.4 greater odds of LVH (p<0.05 for all).

Conclusions: Among children with mild-moderate CKD, adiposity is independently associated with LVMI and LVH over time. This association is greater among females, a finding that may have future clinical and research implications.

Waist-to-height ratio, body mass index, and cardiovascular risk profile in children with chronic kidney disease

BACKGROUND

Cardiovascular (CV) risk is high in children with chronic kidney disease (CKD), and further compounded in those who are overweight. Children with CKD have a unique body habitus not accurately assessed by body mass index (BMI). Waist-to-height ratio (WHr), a better predictor of CV risk in populations with short stature, has not been investigated in children with CKD.

METHODS

Analysis of 1723 visits of 593 participants enrolled in the Chronic Kidney Disease in Children (CKiD) study was conducted. CKiD participants had BMI and WHr measured and classified as follows: (1) lean (WHr ≤ 0.49, BMI < 85th percentile); (2) WHr-overweight (WHr > 0.49, BMI < 85th percentile); (3) BMI-overweight (WHr ≤ 0.49, BMI ≥ 85th percentile); or (4) overweight by both BMI and WHr. Left ventricular mass index (LVMI), fasting lipids, fibroblast growth factor 23 (FGF23), blood pressure, and glucose were measured as markers of CV risk. Linear mixed-effects regression was used to evaluate differences in CV markers between overweight and lean groups.

RESULTS

Participants were 12.2 years old, 60% male, and 17% African-American. Approximately 15% were overweight by WHr but not by BMI. Overweight status by WHr-only or both WHr and BMI was associated with lower high-density lipoprotein (HDL) and higher LVMI, triglycerides, and non-HDL cholesterol compared to lean. CV markers of participants overweight by BMI-only were similar to those of lean children.

CONCLUSIONS

WHr-adiposity is associated with an adverse CV risk profile in children with CKD. A significant proportion of children with central adiposity are missed by BMI. WHr should be utilized as a screening tool for CV risk in this population.

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

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

Effect of bariatric surgery on urinary sphingolipids in adolescents with severe obesity

BACKGROUND

Untreated severe obesity of adolescents is associated with abnormal kidney function and development of chronic kidney disease. Lipotoxicity due to lipid accumulation in glomeruli might be an important mechanism in the progression of kidney disease in obesity.

OBJECTIVE

To assess subclinical glomerular injury by measuring urinary sphingolipids in adolescents with severe obesity before and after weight loss surgery. We hypothesized that the levels of urinary sphingolipids would be elevated at baseline and improve after weight reduction.

SETTING

Cincinnati Children's Hospital Medical Center, University of Cincinnati.

METHODS

Ten adolescents undergoing bariatric surgery with no microalbuminuria and normal kidney function were selected. Urinary sphingolipids (ceramides, glycosphingolipids, and sphingomyelins) were quantified using ultra performance liquid chromatography electrospray ionization tandem mass spectrometry at baseline and 1 year postoperatively. The levels of sphingolipids were compared with lean and moderately obese controls.

RESULTS

Participants with severe obesity had a mean baseline body mass index of 50 kg/m² that decreased to 36 kg/m² at 1 year postsurgery (28% reduction). Almost all urinary ceramides, glycosphingolipids, and sphingomyelin species were significantly elevated in participants with severe obesity compared with controls at baseline (P<.01). One year after weight loss surgery, levels of urinary sphingolipids improved but were still significantly elevated compared with controls.

CONCLUSIONS

Our study indicates that severe obesity is associated with increased urinary excretion of sphingolipids despite the absence of microalbuminuria or decreased kidney function. Urinary sphingolipids may therefore represent a marker of early (subclinical) glomerular injury in adolescents with severe obesity.

Associations Between Weight Loss, Kidney Function Decline, and Risk of ESRD in the Chronic Kidney Disease in Children (CKiD) Cohort Study

BACKGROUND

Anorexia and malnutrition are associated with poor outcomes in children with chronic kidney disease (CKD).

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

We assessed changes in body mass index (BMI) as kidney function declines and its association with risk for end-stage renal disease (ESRD) among 854 participants followed between 2005 to 2013 in the CKD in Children (CKiD) Study.

PREDICTORS

Repeated measurements of estimated glomerular filtration rate (eGFR) by serum creatinine concentration in our trajectory analysis using mixed models; change in BMI z score (per year) after eGFR decreased to <35mL/min/1.73m² in logistic regression models.

OUTCOMES

Repeated measurements of BMI z score (as a reflection of weight status) in our trajectory analysis; ESRD in logistic regression models.

RESULTS

During a mean longitudinal follow-up of 3.4 years, BMI z scores remained stable until eGFR decreased to <35mL/min/1.73m². When eGFR decreased to <35mL/min/1.73m², a mean decline in BMI z score of 0.13 (95% CI, 0.09-0.17) was noted with each 10-mL/min/1.73m² further decline in eGFR. This was statistically significantly different from the weight trajectory when eGFR was ≥35mL/min/1.73 m² (P<0.001). Among children and adolescents with significant weight loss (defined as decline in BMI z score > 0.2 per year) after eGFR decreased to <35mL/min/1.73m², the odds of ESRD was 3.28 (95% CI, 1.53-7.05) times greater compared with participants with stable BMI z scores (BMI z score change per year of 0-0.1).

LIMITATIONS

Observational nature of our study, lack of longitudinal assessments of inflammatory markers.

CONCLUSIONS

In children and adolescents with CKD, weight loss mostly occurs when eGFR decreases to <35mL/min/1.73m², and this weight loss was associated with higher risk for ESRD. Further studies are needed to define the reasons for the association between weight loss and more rapid progression to ESRD in children and adolescents.

Short, frequent, 5-days-per-week, in-center hemodialysis versus 3-days-per week treatment: a randomized crossover pilot trial through the Midwest Pediatric Nephrology Consortium

BACKGROUND

No controlled trials in children with end-stage kidney disease have assessed the benefits of more frequently administered hemodialysis (HD).

METHODS

We conducted a multicenter, crossover pilot trial to determine if short, more frequent (5 days per week) in-center HD was feasible and associated with improvements in blood pressure compared with three conventional HD treatments per week. Because adult studies have not controlled for the weekly duration of dialysis, we fixed the total treatment time at 12 h a week of dialysis during two 3-month study periods; only frequency varied from 5 to 3 days per week between study periods.

RESULTS

Eight children (median age 16.7 years) consented at three children's hospitals. The prespecified primary composite outcome was a sustained 10% decrease in systolic blood pressure and/or a decrease in antihypertensive medications relative to each study period's baseline. Among the six patients completing both study periods, five (83.3%) experienced the primary outcome during HD performed 5 days per week but not 3 days per week; one of the six (16.7%) achieved that outcome during 3-day but not 5-day (p = 0.22) per week HD. During 5-day HD, all patients had significantly more treatments during which their pre-HD systolic (p = 0.01) or diastolic (p = 0.01) blood pressure was 10% lower than baseline.

CONCLUSIONS

We observed that more frequent HD sessions per week was feasible and associated with improved blood pressure control, but barriers to changing thrice-weekly standard of care include financial reimbursement and the time demands associated with more frequent treatments.

Vascular Stiffness in Children With Chronic Kidney Disease

Carotid-femoral pulse wave velocity (cfPWV) is a measure of arterial stiffness associated with cardiovascular events in the general population and in adults with chronic kidney disease. However, few data exist regarding cfPWV in children with chronic kidney disease. We compared observed cfPWV assessed via applanation tonometry in children enrolled in the CKiD cohort study (Chronic Kidney Disease in Children) to normative data in healthy children and examined risk factors associated with elevated cfPWV. cfPWV Z score for height/gender and age/gender was calculated from and compared with published pediatric norms. Multivariable linear regression was used to assess the relationship between cfPWV and age, gender, race, body mass index, diagnosis, urine protein-creatinine ratio, mean arterial pressure, heart rate, number of antihypertensive medications, uric acid, and serum low-density lipoprotein. Of the 95 participants with measured cfPWV, 60% were male, 19% were black, 46% had glomerular cause of chronic kidney disease, 22% had urine protein-creatinine ratio 0.5 to 2.0 mg/mg and 9% had >2.0 mg/mg, mean age was 15.1 years, average mean arterial pressure was 80 mm Hg, and median glomerular filtration rate was 63 mL/min per 1.73 m² Mean cfPWV was 5.0 m/s (SD, 0.8 m/s); mean cfPWV Z score by height/gender norms was -0.1 (SD, 1.1). cfPWV increased significantly with age, mean arterial pressure, and black race in multivariable analysis; no other variables, including glomerular filtration rate, were independently associated with cfPWV. In this pediatric cohort with mild kidney dysfunction, arterial stiffness was comparable to that of normal children. Future research is needed to examine the impact of chronic kidney disease progression on arterial stiffness and associated cardiovascular parameters in children.

Cystatin C and Cardiac Measures in Children and Adolescents With CKD

BACKGROUND

Cardiovascular disease (CVD) is highly prevalent among children with chronic kidney disease (CKD). Cystatin C is an established marker of kidney function and an emerging biomarker for CVD events. We quantified the relationship between cystatin C level and cardiac structure and function over time among children with CKD and assessed whether cystatin C level and diastolic function retained an association after accounting for kidney function.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

678 children and adolescents with mild to moderate CKD enrolled in the CKD in Children (CKiD) Study with 1,228 echocardiographically obtained cardiac structure and function measurements.

PREDICTOR

Serum cystatin C (mg/L) measured annually.

OUTCOMES

Cardiac structure (left ventricular mass index [g/m^2.7]) and cardiac function (shortening fraction; E/A, E'/A', E/E' ratios) measured every other year.

MEASUREMENTS

Demographics and anthropometrics, measured glomerular filtration rate (mGFR), heart rate, blood pressure, hemoglobin z score, serum albumin level, and calcium-phosphorus product.

RESULTS

Independent of time, each 1-mg/L increase in cystatin C level was independently associated with a concurrent 7.7% (95% CI, 5.3%-10.0%) increase in left ventricular mass index, a -4.7% (95% CI, -7.0% to -2.4%) change in E/A ratio, a -6.6% (95% CI, -9.0% to -4.2%) change in E'/A' ratio, and a 2.5% (95% CI, 0.3%-4.7%) increase in E/E' ratio. mGFR was also independently associated with E'/A' ratio. When cystatin C level and mGFR were included in the same model, cystatin C level remained independently associated with E'/A' ratio, whereas mGFR was not.

LIMITATIONS

24% of the cohort was missing data for outcomes of interest or measurements; study population includes only children and adolescents with mild to moderate CKD.

CONCLUSIONS

In this study of children and adolescents with mild to moderate CKD, cystatin C level was independently associated with cardiac structure and diastolic function. Cystatin C level remained able to predict diastolic function decline via E'/A' ratio even after adjusting for mGFR, suggesting that cystatin C level may have an independent role in CVD risk stratification among children and adolescents with CKD.

Cardiovascular Disease Risk Factors and Left Ventricular Hypertrophy in Girls and Boys With CKD

BACKGROUND AND OBJECTIVES

Prior studies suggested that women with CKD have higher risk for cardiovascular disease (CVD) and mortality than men, although putative mechanisms for this higher risk have not been identified. We assessed sex differences in (1) CVD risk factors and left ventricular hypertrophy (LVH), and (2) the relationship of left ventricular mass (LVM) with different measures of body size in children with CKD.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

The study population comprised 681 children with CKD from the Chronic Kidney Disease in Children cohort, contributing 1330 visits. CVD risk factors were compared cross-sectionally by sex. LVH was defined as LVM/height2.7 >95th percentile and LVM relative to estimated lean body mass (eLBM) >95th percentile for age and sex. Differences in LVM by sex were assessed by adjusting for age, weight, height, and eLBM using bivariate and multivariate regression models.

RESULTS

Girls were less likely to have uncontrolled hypertension (26% versus 38%, P=0.001), had lower diastolic BP z-scores (+0.3 versus +0.6, P=0.001), and had lower prevalence of high triglycerides (38% versus 47%, P=0.03) compared with boys. When LVH was defined by LVM indexed to height, girls had higher prevalence of LVH (16% versus 9%, P=0.01); when LVH was defined by LVM relative to eLBM, prevalence of LVH was similar between girls and boys (18% versus 17%, P=0.92). In regression models adjusting for eLBM, no sex differences in LVM were observed.

CONCLUSIONS

Despite lack of increased prevalence of CVD risk factors, indexing LVM to height showed a higher proportion of LVH among girls, while estimates of LVH based on eLBM showed no sex differences. Indexing LVM to eLBM may be an alternative to height indexing in children with CKD.

New Reference Centiles for Left Ventricular Mass Relative to Lean Body Mass in Children

BACKGROUND

Echocardiographic measurement of left ventricular (LV) mass is routinely performed in pediatric patients with elevated cardiovascular risk. The complex relationship between heart growth and body growth in children requires normalization of LV mass to determine its appropriateness relative to body size. LV mass is strongly determined by lean body mass (LBM). Using new LBM predictive equations, the investigators generated sex-specific LV mass-for-LBM centile curves for children 5 to 18 years of age.

METHODS

This retrospective study used M-mode echocardiographic data collected from 1995 through 2003 from 939 boys and 771 girls between 5 and 18 years of age (body mass index < 85th percentile for sex and age) to create smoothed sex-specific LV mass-for-LBM reference centile curves using the Lamda Mu Sigma method. The newly developed reference centiles were applied to children with essential hypertension and with chronic kidney disease, groups known to be at high risk for LV hypertrophy (LVH). The identification of LVH using two different normalization approaches was compared: LV mass-for-LBM and LV mass index-for-age percentiles.

RESULTS

Among 231 children at risk for LVH, on average, relative LV mass was higher using the LV mass index-for-age percentile method than the LV mass-for-LBM percentile method. LVH was more likely to be diagnosed among overweight children and less likely among thin children.

CONCLUSIONS

This study provides new LV mass reference centiles expressing LV mass relative to LBM, the strongest determinant of LV mass. These reference centiles may allow more accurate stratification of cardiovascular risk in children.

Renal and Cardiovascular Morbidities Associated with APOL1 Status among African-American and Non-African-American Children with Focal Segmental Glomerulosclerosis

BACKGROUND AND OBJECTIVES

African-American (AA) children with focal segmental glomerulosclerosis (FSGS) have later onset disease that progresses more rapidly than in non-AA children. It is unclear how APOL1 genotypes contribute to kidney disease risk, progression, and cardiovascular morbidity in children.

DESIGN SETTING PARTICIPANTS AND MEASUREMENTS

We examined the prevalence of APOL1 genotypes and associated cardiovascular phenotypes among children with FSGS in the Chronic Kidney Disease in Children (CKiD) study; an ongoing multicenter prospective cohort study of children aged 1-16 years with mild to moderate kidney disease.

RESULTS

A total of 140 AA children in the CKiD study were genotyped. High risk (HR) APOL1 genotypes were present in 24% of AA children (33/140) and were associated with FSGS, p < 0.001. FSGS was the most common cause of glomerular disease in children with HR APOL1 (89%; 25/28). Of 32 AA children with FSGS, 25 (78%) had HR APOL1. Compared to children with low risk APOL1 and FSGS (comprising 36 non-AA and 7 AA), children with HR APOL1 developed FSGS at a later age, 12.0 (IQR: 9.5, 12.5) vs. 5.5 (2.5, 11.5) years, p = 0.004, had a higher prevalence of uncontrolled hypertension (52 vs. 33%, p = 0.13), left ventricular hypertrophy (LVH) (53 vs. 12%, p < 0.01), C-reactive protein > 3 mg/l (33 vs. 15%, p = 0.12), and obesity (48 vs. 19%, p = 0.01). There were no differences in glomerular filtration rate, hemoglobin, iPTH, or calcium-phosphate product.

CONCLUSION

AA children with HR APOL1 genotype and FSGS have increase prevalence of obesity and LVH despite a later age of FSGS onset, while adjusting for socioeconomic status. Treatment of obesity may be an important component of chronic kidney disease and LVH management in this population.

Predictors of Rapid Progression of Glomerular and Nonglomerular Kidney Disease in Children and Adolescents: The Chronic Kidney Disease in Children (CKiD) Cohort

BACKGROUND

Few studies have prospectively evaluated the progression of chronic kidney disease (CKD) in children and adolescents, as well as factors associated with progression.

STUDY DESIGN

Prospective multicenter observational cohort study.

SETTING & PARTICIPANTS

496 children and adolescents with CKD enrolled in the Chronic Kidney Disease in Children (CKiD) Study.

PREDICTORS

Proteinuria, hypoalbuminemia, blood pressure, dyslipidemia, and anemia.

OUTCOMES

Parametric failure-time models were used to characterize adjusted associations between baseline levels and changes in predictors and time to a composite event of renal replacement therapy or 50% decline in glomerular filtration rate (GFR).

RESULTS

398 patients had nonglomerular disease and 98 had glomerular disease; of these, 29% and 41%, respectively, progressed to the composite event after median follow-ups of 5.2 and 3.7 years, respectively. Demographic and clinical characteristics and outcomes differed substantially according to the underlying diagnosis; hence, risk factors for progression were assessed in stratified analyses, and formal interactions by diagnosis were performed. Among patients with nonglomerular disease and after adjusting for baseline GFR, times to the composite event were significantly shorter with urinary protein-creatinine ratio > 2mg/mg, hypoalbuminemia, elevated blood pressure, dyslipidemia, male sex, and anemia, by 79%, 69%, 38%, 40%, 38%, and 45%, respectively. Among patients with glomerular disease, urinary protein-creatinine ratio >2mg/mg, hypoalbuminemia, and elevated blood pressure were associated with significantly reduced times to the composite event by 94%, 71%, and 67%, respectively. Variables expressing change in patient clinical status over the initial year of the study contributed significantly to the model, which was cross-validated internally.

LIMITATIONS

Small number of events in glomerular patients and use of internal cross-validation.

CONCLUSIONS

Characterization and modeling of risk factors for CKD progression can be used to predict the extent to which these factors, either alone or in combination, would shorten the time to renal replacement therapy or 50% decline in GFR in children with CKD.

Correlates of leptin in children with chronic kidney disease

OBJECTIVE

To investigate the relative associations of renal function, obesity, and inflammation with serum leptin levels in children with chronic kidney disease (CKD).

STUDY DESIGN

This was a cross-sectional analysis of 317 children from the Chronic Kidney Disease in Children study, a large cohort of pediatric patients with stage II-IV CKD. Linear regression modeling was used to evaluate the association of serum leptin level with glomerular filtration rate calculated using the plasma iohexol disappearance curve, demographics, body mass index (BMI), and cardiovascular risk factors, including inflammatory cytokines, insulin resistance, and serum lipid levels.

RESULTS

In univariate analyses, elevated serum leptin level was significantly associated with increased BMI, older age, and female sex (P < .001 for all). Leptin level also correlated positively with serum triglycerides and insulin resistance (P < .001) and negatively with serum high-density lipoprotein cholesterol (P = .002). Leptin level was not associated with glomerular filtration rate calculated using the plasma iohexol disappearance curve or inflammatory cytokines. In multivariate analysis, BMI, age, female sex, and serum triglyceride levels were significantly associated with serum leptin level.

CONCLUSION

Increased leptin production was associated with female sex, older age, and adiposity in children with mild to moderate CKD. Renal function was not associated with serum leptin level, indicating that decreased clearance does not contribute to elevated leptin levels.

Heart rate and blood pressure variability in children with chronic kidney disease: a report from the CKiD study

BACKGROUND

Autonomic nervous system dysfunction and sympathetic nervous system over-activity play important roles in the development of hypertension associated with chronic kidney disease (CKD). In adults, increased blood pressure variability (BPV) appears to be directly related to sympathetic over-activity with increased risk of end-organ damage and cardiovascular events. Decreased heart rate variability (HRV) has been observed in adults with CKD, and is an independent predictor of mortality.

METHODS

The purpose of this study was to evaluate BPV and HRV in pediatric patients enrolled in the Chronic Kidney Disease in Children Study. Ambulatory blood pressure monitoring data were available for analysis of 215 person-visits from 144 children that were not receiving antihypertensive medications.

RESULTS

BPV and HRV were determined by standard deviation and coefficient of variation for heart rate and systolic and diastolic blood pressure for each patient averaged for wake/sleep periods during 24-h monitoring. Uniformly lower values were displayed during sleep versus wake periods: BPV was 20 % lower during sleep (p < 0.001) and HRV was 30 % lower during sleep (p < 0.001). A significant increase in systolic BPV was observed in hypertensive children compared to children with normal blood pressure (6.9 %, p = 0.009). Increased diastolic BPV was detected among hypertensive children during sleep period compared to children with normal blood pressure (11.5 %, p = 0.008). There was a significant decrease in HRV in hypertensive compared to normotensive children (-8.2 %, p = 0.006).

CONCLUSIONS

These findings are similar to those in adult patients and may underscore childhood origin and natural progression of adverse cardiovascular outcomes in adults with CKD.

Ceramides and cardiac function in children with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is associated with increased incidence of cardiac dysfunction. Recent animal studies have demonstrated that elevated levels of ceramides cause dilated lipotoxic cardiomyopathy. We hypothesized ceramides are increased in children with CKD and associated with abnormal cardiac structure and function.

METHODS

Ceramide levels were determined in 93 children aged 1-16 years enrolled in the Chronic Kidney Disease in Children (CKiD) study and compared to levels from 24 healthy controls. Complete demographic, clinical, and laboratory information, and ceramide measurements were analyzed cross-sectionally. Echocardiography was performed to determine cardiac structure and function.

RESULTS

Very long-chain C24:0 ceramides were the most abundant species in both control (56 %) and CKD subjects (55 %), followed by C24:1 (controls 19 %, CKD 23 %) and C22:0 (controls 19 %, CKD 13 %). Total serum ceramide levels were significantly higher in CKD children versus controls (p < 0.001). Ceramide metabolites lactosylceramide, C24:0L, and C16:0L were significantly higher in CKD subjects than controls (p < 0.001). The proportion of C24:0L was dramatically higher in CKD (59 %) versus control (17 %) subjects (p < 0.001). In adjusted multivariate analyses, higher log10C24:0L and log10C16:0L were significant predictors of lower shortening fraction and mid-wall shortening.

CONCLUSIONS

Ceramide levels are increased in children with CKD. Our study identified lactosylceramides as an independent predictor of lower systolic function in these children.

Perioperative outcomes of adolescents undergoing bariatric surgery: the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) study

IMPORTANCE

Severe obesity in childhood is a major health problem with few effective treatments. Weight-loss surgery (WLS) is being used to treat severely obese adolescents, although with very limited data regarding surgical safety for currently used, minimally invasive procedures.

OBJECTIVE

To assess the preoperative clinical characteristics and perioperative safety outcomes of severely obese adolescents undergoing WLS.

DESIGN, SETTING, AND PARTICIPANTS

This prospective, multisite observational study enrolled patients from February 28, 2007, through December 30, 2011. Consecutive patients aged 19 years or younger who were approved to undergo WLS (n = 277) were offered enrollment into the study at 5 academic referral centers in the United States; 13 declined participation and 22 did not undergo surgery after enrollment, thus the final analysis cohort consisted of 242 individuals. There were no withdrawals.

MAIN OUTCOMES AND MEASURES

This analysis examined preoperative anthropometrics, comorbid conditions, and major and minor complications occurring within 30 days of operation. All data were collected in a standardized fashion. Reoperations and hospital readmissions were adjudicated by independent reviewers to assess relatedness to the WLS procedure.

RESULTS

The mean (SD) age of participants was 17.1 (1.6) years and the median body mass index (calculated as weight in kilograms divided by height in meters squared) was 50.5. Fifty-one percent demonstrated 4 or more major comorbid conditions. Laparoscopic Roux-en-Y gastric bypass, vertical sleeve gastrectomy, and adjustable gastric banding were performed in 66%, 28%, and 6% of patients, respectively. There were no deaths during the initial hospitalization or within 30 days of operation; major complications (eg, reoperation) were seen in 19 patients (8%). Minor complications (eg, readmission for dehydration) were noted in 36 patients (15%). All reoperations and 85% of readmissions were related to WLS.

CONCLUSIONS AND RELEVANCE

In this series, adolescents with severe obesity presented with abundant comorbid conditions. We observed a favorable short-term complication profile, supporting the early postoperative safety of WLS in select adolescents. Further longitudinal study of this cohort will permit accurate assessment of long-term outcomes for adolescents undergoing bariatric surgery.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00474318.

The effect of obesity in adolescence on adult health status

OBJECTIVE

To test the hypothesis that adolescent obesity would be associated with greater risks of adverse health in severely obese adults.

METHODS

Before weight loss surgery, adult participants in the Longitudinal Assessment of Bariatric Surgery-2 underwent detailed anthropometric and comorbidity assessment. Weight status at age 18 was retrospectively determined. Participants who were ≥80% certain of recalled height and weight at age 18 (1502 of 2308) were included. Log binomial regression was used to evaluate whether weight status at age 18 was independently associated with risk of comorbid conditions at time of surgery controlling for potential confounders.

RESULTS

Median age and adult body mass index (BMI) were 47 years and 46, respectively. At age 18, 42% of subjects were healthy weight, 29% overweight, 16% class 1 obese, and 13% class ≥2 obese. Compared with healthy weight at age 18, class ≥2 obesity at age 18 independently increased the risk of lower-extremity venous edema with skin manifestations by 435% (P < .0001), severe walking limitation by 321% (P < .0001), abnormal kidney function by 302% (P < .0001), polycystic ovary syndrome by 74% (P = .03), asthma by 48% (P = .01), diabetes by 42% (P < .01), obstructive sleep apnea by 25% (P < .01), and hypertension (by varying degrees based on age and gender). Conversely, the associated risk of hyperlipidemia was reduced by 61% (P < .01).

CONCLUSIONS

Severe obesity at age 18 was independently associated with increased risk of several comorbid conditions in adults undergoing bariatric surgery.

BP control and left ventricular hypertrophy regression in children with CKD

In adult patients with CKD, hypertension is linked to the development of left ventricular hypertrophy, but whether this association exists in children with CKD has not been determined conclusively. To assess the relationship between BP and left ventricular hypertrophy, we prospectively analyzed data from the Chronic Kidney Disease in Children cohort. In total, 478 subjects were enrolled, and 435, 321, and 142 subjects remained enrolled at years 1, 3, and 5, respectively. Echocardiograms were obtained 1 year after study entry and then every 2 years; BP was measured annually. A linear mixed model was used to assess the effect of BP on left ventricular mass index, which was measured at three different visits, and a mixed logistic model was used to assess left ventricular hypertrophy. These models were part of a joint longitudinal and survival model to adjust for informative dropout. Predictors of left ventricular mass index included systolic BP, anemia, and use of antihypertensive medications other than angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. Predictors of left ventricular hypertrophy included systolic BP, female sex, anemia, and use of other antihypertensive medications. Over 4 years, the adjusted prevalence of left ventricular hypertrophy decreased from 15.3% to 12.6% in a systolic BP model and from 15.1% to 12.6% in a diastolic BP model. These results indicate that a decline in BP may predict a decline in left ventricular hypertrophy in children with CKD and suggest additional factors that warrant additional investigation as predictors of left ventricular hypertrophy in these patients.

Secondhand smoke exposure is associated with proteinuria in children with chronic kidney disease

BACKGROUND

In adults with chronic kidney disease (CKD), cigarette smoking is associated with an increased risk for CKD progression and transplant failure. In children, secondhand smoke (SHS) exposure has been associated with elevated blood pressure. There are no studies on the prevalence and effect of SHS exposure in CKD.

METHODS

Subjects were enrolled in the Chronic Kidney Disease in Children (CKiD) Study, an observational cohort of 366 children aged 1 to 16 years with CKD. Secondhand smoke exposure was obtained via questionnaire. SHS exposure was also determined based on urine cotinine (Ucot) measurements (1 ng/mL ≤ Ucot < 75 ng/mL). The cross-sectional association of SHS exposure with proteinuria was assessed.

RESULTS

Using Ucot, 22 % of subjects were exposed to SHS. SHS exposure was significantly associated with lower maternal education and African American race, and a greater prevalence of nephrotic range proteinuria and left ventricular hypertrophy. In a multivariate model (including sex, age, race, maternal education, income level, private insurance status, abnormal birth history and CKD diagnosis), the prevalence odds of nephrotic range proteinuria was 2.64, (95 % confidence interval 1.08, 6.42) higher in children exposed to SHS compared to those unexposed.

CONCLUSIONS

In our cohort of children with CKD, SHS exposure was common (22 %) and independently associated with nephrotic range proteinuria. Exposure to SHS may be an important factor to consider in CKD progression.