Longitudinal Relationship Between Anemia and Statural Growth Impairment in Children and Adolescents With Nonglomerular CKD: Findings From the Chronic Kidney Disease in Children (CKiD) Study

RATIONALE & OBJECTIVE

Anemia and statural growth impairment are both prevalent in children with nonglomerular chronic kidney disease (CKD) and are associated with poor quality of life and increased morbidity and mortality. However, to date no longitudinal studies have demonstrated a relationship between anemia and statural growth in this population.

STUDY DESIGN

The CKD in Children (CKiD) study is a multicenter prospective cohort study with over 15 years of follow-up observation.

SETTING & PARTICIPANTS

CKiD participants younger than 22 years with nonglomerular CKD who had not reached final adult height.

EXPOSURE

Age-, sex-, and race-specific hemoglobin z score.

OUTCOME

Age- and sex-specific height z score.

ANALYTICAL APPROACH

The relationship between hemoglobin and height was quantified using (1) multivariable repeated measures paired person-visit analysis, and (2) multivariable repeated measures linear mixed model analysis. Both models were adjusted for age, sex, body mass index, estimated glomerular filtration rate, acidosis, and medication use.

RESULTS

Overall, 67% of the 510 participants studied had declining hemoglobin z score trajectories over the follow-up period, which included 1,763 person-visits. Compared with average hemoglobin z scores of≥0, average hemoglobin z scores of less than -1.0 were independently associated with significant growth impairment at the subsequent study visit, with height z score decline ranging from 0.24 to 0.35. Importantly, in 50% of cases hemoglobin z scores of less than -1.0 corresponded to hemoglobin values higher than those used as cutoffs defining anemia in the KDIGO clinical practice guideline for anemia in CKD. When stratified by age, the magnitude of the association peaked in participants aged 9 years. In line with paired-visit analyses, our mixed model analysis demonstrated that in participants with baseline hemoglobin z score less than -1.0, a hemoglobin z score decline over the follow-up period was associated with a statistically significant concurrent decrease in height z score.

LIMITATIONS

Limited ability to infer causality.

CONCLUSIONS

Hemoglobin decline is associated with growth impairment over time in children with mild to moderate nonglomerular CKD, even before hemoglobin levels reach the cutoffs that are currently used to define anemia in this population.

The Relationship Between Neighborhood Disadvantage and Kidney Disease Progression in the Chronic Kidney Disease in Children (CKiD) Cohort

RATIONALE & OBJECTIVE

To examine the relationship between neighborhood poverty and deprivation, chronic kidney disease (CKD) comorbidities, and disease progression in children with CKD.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

Children with mild to moderate CKD enrolled in the CKiD (Chronic Kidney Disease in Children) study with available US Census data.

EXPOSURE

Neighborhood poverty and neighborhood disadvantage.

OUTCOME

Binary outcomes of short stature, obesity, hypertension, and health care utilization for cross-sectional analysis; a CKD progression end point (incident kidney replacement therapy [KRT] or 50% loss in estimated glomerular filtration rate), and mode of first KRT for time-to-event analysis.

ANALYTICAL APPROACH

Cross-sectional analysis of health characteristics at time of first Census data collection using logistic regression to estimate odds ratios. Risk for CKD progression was analyzed using a Cox proportional hazard model. Multivariable models were adjusted for race, ethnicity, sex, and family income.

RESULTS

There was strong agreement between family and neighborhood socioeconomic characteristics. Risk for short stature, hospitalization, and emergency department (ED) use were significantly associated with lower neighborhood income. After controlling for race, ethnicity, sex, and family income, the odds of hospitalization (OR, 1.71 [95% CI, 1.08-2.71]) and ED use (OR, 1.56 [95% CI, 1.02-2.40]) remained higher for those with lower neighborhood income. The hazard ratio of reaching the CKD progression outcome for participants living in lower income neighborhoods was significantly increased in the unadjusted model only (1.38 [95% CI, 1.02-1.87]). Likelihood of undergoing a preemptive transplant was decreased with lower neighborhood income (OR, 0.47 [95% CI, 0.24-0.96]) and higher neighborhood deprivation (OR, 0.31 [95% CI, 0.10-0.97]), but these associations did not persist after controlling for participant characteristics.

LIMITATIONS

Limited generalizability, as only those with consistent longitudinal nephrology care were studied.

CONCLUSIONS

Neighborhood-level socioeconomic status (SES) was associated with poorer health characteristics and CKD progression in univariable analysis. However, the relationships were attenuated after accounting for participant-level factors including race. A persistent association of neighborhood poverty with hospitalizations and ED suggests an independent effect of SES on health care utilization, the causes for which deserve additional study.

"Save the Vein" Initiative in Children With CKD: A Quality Improvement Study

RATIONALE & OBJECTIVE

The preferred vascular access for hemodialysis recipients is an arteriovenous fistula in the nondominant arm. Prior placement of a peripheral intravenous (PIV) catheter can lead to vascular injury and limit options for arteriovenous fistula creation, a particular problem for children, who may need hemodialysis for their entire lifetime. We instituted an initiative to increase the frequency of PIV catheter placement in the dominant arm for hospitalized pediatric patients with advanced chronic kidney disease (CKD).

STUDY DESIGN

Quality improvement initiative.

SETTING & PARTICIPANTS

Children with CKD stage 3-5, receiving dialysis, and/or following kidney transplantation who were hospitalized at one children's hospital between September 2018 and August 2020.

QUALITY IMPROVEMENT ACTIVITIES

Retrospective data on PIV catheter location for patients from January 1 to June 30, 2017, served as baseline data. Quality improvement activities consisted of: 1) education of the multidisciplinary treatment team, patients, and parents regarding importance of vein preservation; 2) placement of individualized notes in the electronic medical record identifying the preferred arm for PIV catheter placement; 3) use of "restricted extremity" arm bands; and 4) vascular access team participation to minimize attempts for PIV catheter placement.

OUTCOME

Monthly compliance with placement of PIV catheters in dominant arms.

ANALYTICAL APPROACH

Location of PIV catheter placements were determined monthly and used to create run charts describing compliance.

RESULTS

At baseline and before institution of this initiative, 34 of 72 (47%) PIV catheters were placed in patients' dominant arms, with only 2 of 8 (25%) PIV catheters placed in the dominant arm for children aged<5 years. After instituting the initiative, 345 of 371 (93%) PIV catheters were placed in the dominant arm of 93 children; in children aged<5 years, 58 of 62 (94%) PIV catheters were placed in the dominant arm. Only 38 of 371 (10%) PIV catheters were placed in the antecubital vein.

LIMITATIONS

Single-center study.

CONCLUSIONS

Education regarding the importance of vein preservation, along with implementation of a standardized process for identifying children for whom vein preservation is important, can help direct PIV catheter placement and potentially preserve vasculature in pediatric patients with CKD.

Heterogeneous Recommendations for School Attendance in Children With Chronic Kidney Diseases During the COVID-19 Pandemic in Europe

Introduction: After worldwide closures due to the COVID-19 pandemic, schools have reopened in most European countries in late 2020. Consequently, for children with chronic diseases the risks of COVID-19 have to be weighed against the long-time risks of missing school. Methods: To evaluate the impact of chronic diseases on school attendance for children in Europe during the COVID-19 pandemic we conducted a survey among members of the European Society for Pediatric Nephrology (ESPN) between September and November 2020. We asked for current forms of schooling, the existence of national guidelines, parental concerns, and the pediatric nephrologists recommendations for school attendance for specific virtual patients with chronic kidney disease (CKD). Results: Recommendations varied widely among pediatric nephrologists. A minority stated that specific recommendations for COVID-19 risk in children with kidney diseases existed in their country from local health authorities (9 of 29 countries; 31%) and/or national pediatric nephrology societies (9 of 29 countries; 31%). Over 90% of physicians have experienced parents keeping their children out of school against medical advice of their health providers and about 50% have experienced their patients being refused by school authorities. Consequently, 25% of all pediatric nephrologists estimated that more than 10% of their patients will not attend school regularly. Conclusion: COVID-19 causes educational deficits in the already vulnerable population of children with CKD. As the evidence for the course of COVID-19 in children with chronic diseases grows, rapidly adapted recommendations from pediatric societies could help reduce uncertainty among doctors, patients, and parents.

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.