Hemoglobin of 12 g/dl and above is not associated with increased cardiovascular morbidity in children on hemodialysis

Response to oral iron therapy in children with anemia of chronic kidney disease

BACKGROUND

Anemia is a common complication of chronic kidney disease (CKD) and oral iron is recommended as initial therapy. However, response to iron therapy in children with non-dialysis CKD has not been formally assessed.

METHODS

We reviewed medical records of pediatric patients with stages II-IV CKD followed in two New York metropolitan area medical centers between 2010 and 2020 and identified subjects who received oral iron therapy. Response to therapy at follow-up visits was assessed by improvement of hemoglobin, resolution of anemia by the 2012 KDIGO definition, and changes in iron status. Potential predictors of response were examined using regression analyses (adjusted for age, sex, eGFR, and center).

RESULTS

Study criteria were met by 65 children (median age 12 years, 35 males) with a median time between visits of 81 days. Median eGFR was 44 mL/min/1.73 m2, and 40.7% had glomerular CKD etiology. Following iron therapy, hemoglobin improved from 10.2 to 10.8 g/dL (p < 0.001), hematocrit from 31.3 to 32.8% (p < 0.001), serum iron from 49 to 66 mcg/dL (p < 0.001), and transferrin saturation from 16 to 21.4% (p < 0.001). There was no significant change in serum ferritin (55.0 to 44.9 ng/mL). Anemia (defined according to KDIGO) resolved in 29.3% of children. No improvement in hemoglobin/hematocrit was seen in 35% of children, and no transferrin saturation improvement in 26.9%. There was no correlation between changes in hemoglobin and changes in transferrin saturation/serum iron, but there was an inverse correlation between changes in hemoglobin and changes in ferritin. The severity of anemia and alkaline phosphatase at baseline inversely correlated with treatment response.

CONCLUSIONS

Anemia was resistant to 3 months of oral iron therapy in ~ 30% of children with CKD. Children with more severe anemia at baseline had better treatment response, calling for additional studies to refine approaches to iron therapy in children with anemia of CKD and to identify additional predictors of treatment response.

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.

A longitudinal analysis of the effect of anemia on executive functions in children with mild to moderate chronic kidney disease

BACKGROUND

Children with chronic kidney disease (CKD) are at risk for cognitive dysfunction. The aim of this study was to investigate associations between executive functions (EF), anemia, and iron deficiency.

METHODS

A total of 688 children > 6 years of age enrolled in the Chronic Kidney Disease in Children (CKiD) study who underwent evaluation for EF were included. Hemoglobin (Hgb) was characterized as low (1st-5th percentile) or very low (< 1st percentile) compared to normative values for age, sex, and race irrespective of erythropoiesis-stimulating agent (ESA) usage. Longitudinal analysis was conducted using consecutive visit pairs, with anemia status defined as new onset, resolved, or persistent. Linear mixed models with random intercept were used and adjusted for key covariates.

RESULTS

Anemia was present in 41% of children, and median Hgb was 11.8 gm/dl. New onset anemia was associated with lower digit span total score (- 0.75, 95% CI - 1.36, - 0.15, p = 0.01). Persistent anemia was associated with lower scores on color-word inhibition/switching (β =  - 0.98; 95% CI - 1.78, - 0.18, p = 0.02). Errors of omission were significantly higher (worse) in those with persistent anemia (β = 2.67, 95% CI 0.18, 5.17, p = 0.04). Very low Hgb levels were significantly associated with lower color-word inhibition/switching scores (β =  - 1.33, 95% CI - 2.16, - 0.51; p = 0.002). Anemia and low GFR were associated with lower category fluency scores compared to non-anemic subjects with higher GFR (β =  - 1.09, 95% CI - 2.09, - 0.10, p = 0.03).

CONCLUSIONS

The presence of anemia, in addition to its severity and duration in children with CKD, is associated with poorer scores on select measures of EF. A higher resolution version of the Graphical abstract is available as Supplementary information.

Subcutaneous C.E.R.A. for the Maintenance Treatment of Anemia in Pediatric Patients With CKD: A Phase 2, Open-Label, Single-Arm, Multicenter Study

RATIONALE & OBJECTIVE

The optimum starting dose of intravenous continuous erythropoietin receptor activator (C.E.R.A.) has been previously determined; this study ascertains the optimum starting dose of subcutaneous C.E.R.A. administration in pediatric patients.

STUDY DESIGN

Phase 2, open-label, single-arm, multicenter study.

SETTING & PARTICIPANTS

Patients aged 3 months to 17 years with renal anemia and chronic kidney disease (CKD; including those treated with maintenance dialysis and those not treated with dialysis) who were receiving maintenance treatment with erythropoiesis-stimulating agents (ESAs).

INTERVENTION

Subcutaneous C.E.R.A. administration every 4 weeks (starting dose was based on defined conversion factors).

OUTCOME

The primary outcome was the change in hemoglobin concentration between the baseline and evaluation period for each patient. Secondary efficacy measures and safety were also evaluated.

RESULTS

Forty patients aged 0.4-17.7 years were enrolled. The study achieved its primary outcome: the mean change in hemoglobin concentration was an increase of 0.48g/dL; the 95% confidence interval (0.15-0.82) and standard deviation (±1.03) were within the prespecified boundaries (-1 to 1g/dL and<1.5g/dL, respectively). Mean hemoglobin concentrations were maintained within the target 10-12g/dL range in 24 of 38 patients and within±1g/dL of the baseline in 19 of 38 patients, and the median C.E.R.A. subcutaneous dose decreased over time. Efficacy in key subgroups (age group, dialysis type, prior ESA treatment) was consistent with the primary outcome. Thirty-eight patients completed the core period; 25 chose to enter the safety extension period. Safety was consistent with prior studies, with no new signals.

LIMITATIONS

Single-arm and open-label study; small sample size.

CONCLUSIONS

Pediatric patients with anemia secondary to CKD who were on, or not on, dialysis could be safely and effectively switched from maintenance ESAs to subcutaneous C.E.R.A. administered every 4 weeks, using defined dose-conversion factors to determine the optimum starting dose.

FUNDING

F. Hoffmann-La Roche Ltd.

TRIAL REGISTRATION

The SKIPPER trial registered at ClinicalTrials.gov with study number NCT03552393.

Epidemiology of pediatric chronic kidney disease/kidney failure: learning from registries and cohort studies

Although the concept of chronic kidney disease (CKD) in children is similar to that in adults, pediatric CKD has some peculiarities, and there is less evidence and many factors that are not clearly understood. The past decade has witnessed several additional registry and cohort studies of pediatric CKD and kidney failure. The most common underlying disease in pediatric CKD and kidney failure is congenital anomalies of the kidney and urinary tract (CAKUT), which is one of the major characteristics of CKD in children. The incidence/prevalence of CKD in children varies worldwide. Hypertension and proteinuria are independent risk factors for CKD progression; other factors that may affect CKD progression are primary disease, age, sex, racial/genetic factors, urological problems, low birth weight, and social background. Many studies based on registry data revealed that the risk factors for mortality among children with kidney failure who are receiving kidney replacement therapy are younger age, female sex, non-White race, non-CAKUT etiologies, anemia, hypoalbuminemia, and high estimated glomerular filtration rate at dialysis initiation. The evidence has contributed to clinical practice. The results of these registry-based studies are expected to lead to new improvements in pediatric CKD care.

CARDIOVASCULAR CHANGE IN ATHLETES AT DIFFERENT TRAINING STATUS LEVELS

ABSTRACT Introduction: Heart rate and blood pressure are important physiological indicators that reflect cardiovascular function, and they are widely used because they are convenient and practical to measure. Objective: To study the characteristics of cardiovascular changes in athletes under different training conditions. Methods: Thirty-four male students majoring in physical education in universities (group A) and 22 male non-sports majors (group B) with no formal training history were randomly selected. Heart rate before and after exercise and heart rate recovery rate at different stages of the recovery period were compared. Results: As regards heart rate changes in the recovery phase after loading, both groups showed a continuous decline, although the drop in heart rate of group A was slightly lower than that of group B (153.03± 15.88 beats/min, dropped to 110.69± 15.78 beats/minute, 171.00± 14.67 beats/minute dropped to 122. 82± 13.77 beats/min, respectively). However, the heart rate recovery rate of group A (59.40%) was significantly higher than that of group B (49.42%) (P<0.05). Conclusions: Physical exercise plays a significant role in promoting physical fitness and its effect on improving cardiovascular function is especially evident. Level of evidence II; Therapeutic studies - investigation of treatment results.

Use of erythropoiesis-stimulating agents in children with chronic kidney disease: a systematic review

Background

Erythropoiesis-stimulating agents (ESAs) revolutionized the management of anaemia in chronic kidney disease (CKD) when introduced in the late 1980s. A range of ESA types, preparations and administration modalities now exist, with newer agents requiring less frequent administration. Although systematic reviews and meta-analyses have been published in adults, no systematic review has been conducted investigating ESAs in children.

Methods

The Preferred Reporting Items for Systematic Reviews and Meta-analyses statement for the conduct of systematic reviews was used. All available literature on outcomes relating to ESAs in children with CKD was sought. A search of the MEDLINE, CINAHL and Embase databases was conducted by two independent reviewers. Inclusion criteria were published trials in English, children with chronic and end-stage kidney disease and use of any ESA studied against any outcome measure. An assessment of risk of bias was carried out in all included randomized trials using the criteria from the Cochrane Handbook for Systematic Reviews of Interventions. Two tables were used for data extraction for randomized and observational studies. Study type, participants, inclusion criteria, case characteristics, follow-up duration, ESA type and dosage, interventions and outcomes were extracted by one author.

Results

Of 965 identified articles, 58 were included covering 54 cohorts. Six were randomized trials and 48 were observational studies. A total of 38 studies assessed the efficacy of recombinant human erythropoietin (rHuEPO), 11 of darbepoetin alpha (DA) and 3 of continuous erythropoietin receptor activator (CERA), with 6 studies appraising secondary outcome measures exclusively. Recruitment to studies was a consistent challenge. The most common adverse effect was hypertension, although confounding effects often limited direct correlation. Two large cohort studies demonstrated a greater hazard of death independently associated with high ESA dose. Secondary outcome measures included quality of life measures, growth and nutrition, exercise capacity, injection site pain, cardiovascular function, intelligent quotient, evoked potentials and platelet function.

Conclusions

All ESA preparations and modes of administration were efficacious, with evidence of harm at higher doses. Evidence supports individualizing treatments, with strong consideration given to alternate treatments in patients who appear resistant to ESA therapy. Further research should focus on randomized trials comparing the efficacy of different preparations, treatment options in apparently ESA-resistant cohorts and clarification of meaningful secondary outcomes to consolidate patient-relevant indices.

Targeting optimal PD management in children: what have we learned from the IPPN registry?

National and international registries have great potential for providing data that describe disease burden, treatments, and outcomes especially in rare diseases. In the setting of pediatric end-stage renal disease (ESRD), the available data are limited to highly developed countries, whereas the lack of data from emerging economies blurs the global perspective. In order to improve the pediatric dialysis care worldwide, provide global benchmarking of pediatric dialysis outcome, and assign useful tools and management algorithms based on evidence-based medicine, the International Pediatric Peritoneal Dialysis Network (IPPN) was established in 2007. In recent years, the Registry has provided comprehensive data on relevant clinical issues in pediatric peritoneal dialysis patients including nutritional status, growth, cardiovascular disease, anemia management, mineral and bone disorders, preservation of residual kidney function, access-related complications, and impact of associated comorbidities. A unique feature of the registry is the ability to compare practices and outcomes between countries and world regions. In the current review, we describe study design and collection methods, summarize the core IPPN findings based on its 12-year experience and 13 publications, and discuss the future perspective.

Cardiovascular disease in children with chronic kidney disease

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Impact of immediate post-transplant parenteral iron therapy on the prevalence of anemia and short-term allograft function in a cohort of pediatric and adolescent renal transplant recipients

Anemia is common but under-diagnosed and often inadequately treated in KTX recipients. ID is the major cause of early-onset anemia. We introduced routine use of parenteral (IV) iron in patients (2-18 years) who had KTX between January 2011 and December 2015. We explored the clinical benefits of this practice by comparing the iron-treated subjects [TX] with historical controls who had KTX between 2005 and 2010. The prevalence of anemia at 6 months (early-onset) for the cohort (both the study group and controls) was 55% and for anemia at 12 months (late-onset) was 60%. Although cause-effect relationship may not be proven in a retrospective study design, there was a significant greater frequency of ID and anemia at 3 (P < .02) and 6 months (P < .04), and a reduced allograft function (eGFR < 60 mL/min/1.73 m² ) at 12 (P = .03) and 24 months (P = .04) of KTX in the control arm. Furthermore, a greater proportion of the control arm required either ESA (P = .03) or blood transfusion (P = .04) as a rescue treatment for moderate-to-severe anemia. In conclusion, routine parenteral iron treatment was associated with a lower prevalence of early- and late-onset anemia, and a lower requirement for either ESA rescue or blood transfusion.

The differential effects of anemia on mortality in young and elderly end-stage renal disease patients

Background

The aim of this study was to compare the effect of anemia on clinical outcomes according to age in patients with end-stage renal disease (ESRD).

Methods

A total of 3,409 patients from the Clinical Research Center for ESRD were included and divided into three groups by age: age < 40 (n = 488), 40 ≤ age < 60 (n = 1,650), and age ≥ 60 (n = 1,271). We compared overall and cardiovascular mortality, and all-cause and cardiovascular hospitalization according to mean hemoglobin (Hb) concentration.

Results

Among participants ≥ 60 years of age, the Hb < 10 g/dL group had greater all-cause mortality (adjusted hazard ratio [HR], 2.098; 95% confidence interval [CI], 1.567-2.808; P < 0.001) than the 10 ≤ Hb < 12 g/dL group, whereas among participants < 40 years of age, the Hb ≥ 12 g/dL group had greater mortality than the 10 ≤ Hb < 12 g/dL group. Moreover, in participants ≥ 60 years of age, the HR for all-cause hospitalization for the Hb < 10 g/dL group was significantly greater than that of the 10 ≤ Hb < 12 g/dL group (HR, 1.472; 95% CI, 1.057-2.051; P = 0.022), whereas it was significantly lower in the Hb ≥ 12 g/dL group (HR, 0.544; 95% CI, 0.362-0.820; P = 0.004) However, among participants < 40 years of age, the incidence of all-cause hospitalization did not differ according to the Hb concentration (HR, 1.273; 95% CI, 0.814-1.991; P = 0.290 for the Hb < 10 g/dL group; reference, 10 ≤ Hb < 12 g/dL; HR, 0.787; 95% CI, 0.439-1.410; P = 0.265 for Hb ≥ 12 g/dL group).

Conclusion

The impact of anemia on mortality was more significant in elderly ESRD patients. Strict monitoring and management of anemia should be required for elderly ESRD patients.

Cardiovascular risk factors in children on dialysis: an update

Cardiovascular disease (CVD) is a life-limiting comorbidity in patients with chronic kidney disease (CKD). In childhood, imaging studies have demonstrated early phenotypic characteristics including increases in left ventricular mass, carotid artery intima-media thickness, and pulse wave velocity, which occur even in young children with early stages of CKD. Vascular calcifications are the signature of an advanced phenotype and are mainly found in adolescents and young adults treated with dialysis. Association studies have provided valuable information regarding the significance of a multitude of risk factors in promoting CVD in children with CKD by using intermediate endpoints of measurements of surrogate parameters of CVD. Dialysis aggravates pre-existing risk factors and accelerates the progression of CVD with additional dialysis-related risk factors. Coronary artery calcifications in children and young adults with CKD accumulate in a time-dependent manner on dialysis. Identification of risk factors has led to improved understanding of principal mechanisms of CKD-induced damage to the cardiovascular system. Treatment strategies include assessment and monitoring of individual risk factor load, optimization of treatment of modifiable risk factors, and intensified hemodialysis if early transplantation is not possible.

HIF stabilizers in the management of renal anemia: from bench to bedside to pediatrics

Anemia is a common complication of chronic kidney disease (CKD) in adult and pediatric patients. It has traditionally been treated with erythropoietin therapy and iron supplementation, with great success. With the discovery of the major transcription factor hypoxia inducible factor (HIF) for the erythropoietin gene in 1992, molecules were created that inhibit the HIF prolyl-hydroxylase enzyme. This new class of drug-called HIF stabilizers, or HIF prolyl-hydroxylase inhibitors-prevents the proteasomal degradation of HIF-α, thereby inducing upregulation of the erythropoietin gene. This new strategy for treating CKD anemia is already in phase III clinical trials in adults, and the potential advantages of this therapy are that it is orally active (thereby avoiding injections), and patients are exposed to lower circulating levels of erythropoietin. The long-term safety of this strategy, however, requires elucidation in these trials, particularly since there are many other hypoxia-sensitive genes, notably, angiogenic factors such as vascular endothelial growth factors (VEGF), as well as glycolytic enzymes. As with all new therapies, it is only once a positive benefit: risk profile has been ascertained in adults that the treatment will translate across into pediatrics. Specific issues in the pediatric CKD population are discussed in this review.

Assessment of dialysis adequacy: beyond urea kinetic measurements

Adequacy of dialysis is a term that has been used for many years based on measurement of small solute clearance using urea and creatinine. This has been shown in some but not all studies in adults to correlate with survival. However, small solute clearance is just one minor part of the effectiveness of dialysis and in fact 'optimum' dialysis, rather than 'adequate' dialysis is what most paediatric nephrologists would want for their patients. Additional ways to assess the success of dialysis in children would include dialysis access complications and longevity, preservation of residual kidney function, body composition, biochemical and haematological control, nutrition and growth, discomfort during the dialysis process and psychosocial adjustment including hospitalisation and school attendance. These criteria need to be balanced against a dialysis programme that has the least possible adverse effects on quality of life.

Prevalence and predictors of blood transfusion after pediatric kidney transplantation

BACKGROUND

Blood transfusion after kidney transplant carries a risk of sensitization to the graft as well as blood borne infections. The aim of this study was to describe the prevalence of blood transfusions in pediatric recipients of kidney transplants and to determine the factors associated with transfusions during the perioperative period. Additionally, to describe the changes in hemoglobin levels during the first 12 months following transplant.

METHOD

A retrospective, single center analysis using data collected prospectively between 2010 and 2017. Red blood cell transfusion within the first week after transplant and anemia at 3 months were used as outcomes. Multivariate analysis was performed on significant variates with results described according to odds ratio (OR) and interquartile range (IQR).

RESULTS

Transfusions were given after 21 of 42 (50%) transplants in recipients aged between 1 and 17 years (median 14 years). Age, height, weight, and pre-transplant hemoglobin predicted transfusion in univariate analyses. Regression analysis identified pre-transplant hemoglobin as an independent factor (OR 0.85, IQR 0.73-0.98; p = 0.02). Anemia was present at 3 months after 15 (36%) transplants. Anemia at 3 months was associated with older and larger recipients, lower pre-transplant hemoglobin, and lower estimated glomerular filtration rate (eGFR) on univariate analysis. Logistic regression analysis identified eGFR at 3 months as the only independent predictor of anemia at 3 months (OR 0.93, IQR 0.87-0.99; p = 0.04).

CONCLUSIONS

Transfusions are prevalent in the perioperative period after pediatric kidney transplantation. Lower pre-transplant hemoglobin increases the risk of transfusion. Graft function predicts hemoglobin levels at 3 months.

Impact of Inflammation on Ferritin, Hepcidin and the Management of Iron Deficiency Anemia in Chronic Kidney Disease

Iron deficiency anemia (IDA) is a major problem in chronic kidney disease (CKD), causing increased mortality. Ferritin stores iron, representing iron status. Hepcidin binds to ferroportin, thereby inhibiting iron absorption/efflux. Inflammation in CKD increases ferritin and hepcidin independent of iron status, which reduce iron availability. While intravenous iron therapy (IIT) is superior to oral iron therapy (OIT) in CKD patients with inflammation, OIT is as effective as IIT in those without. Inflammation reduces predictive values of ferritin and hepcidin for iron status and responsiveness to iron therapy. Upper limit of ferritin to predict iron overload is higher in CKD patients with inflammation than in those without. However, magnetic resonance imaging studies show lower cutoff levels of serum ferritin to predict iron overload in dialysis patients with apparent inflammation than upper limit of ferritin proposed by international guidelines. Compared to CKD patients with inflammation, optimal ferritin levels for IDA are lower in those without, requiring reduced iron dose and leading to decreased mortality. The management of IDA should differ between CKD patients with and without inflammation and include minimization of inflammation. Further studies are needed to determine the impact of inflammation on ferritin, hepcidin and therapeutic strategy for IDA in CKD.

Hemoglobin target in children with chronic kidney disease: valuable new information

The international guideline from Kidney Disease: Improving Global Outcomes suggests a hemoglobin target of 11 to 12 g/dl for children with chronic kidney disease. However, information to support this proposal is very limited in the pediatric population. Because of controversy, the unmet need is the establishment of an appropriate target hemoglobin level in children with chronic kidney disease. Here, Rheault and colleagues provide valuable new information, reporting the association of hemoglobin levels with cardiovascular morbidity in pediatric hemodialysis patients.