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Recently, Schwartz et al. (J Am Soc Nephrol 20:629–637, 2009) used data from the National Institutes of Health-funded Chronic Kidney Disease in Children (CKiD) study to generate new equations for estimating the glomerular filtration rate (eGFR), including an update of the commonly used bedside equation. However, it is unclear if the equation can be generalized to a broader pediatric population. We have used the updated equation on a sample of pediatric patients with less impaired renal function to evaluate the correlation between the new Schwartz equation and measured GFR by iothalamate clearance. We retrospectively analyzed 738 iothalamate clearance tests from 503 patients with a mean serum creatinine of 0.50 mg/dl whose ages ranged from 1 to 16 years. We measured bias, precision, and accuracy and performed a Bland–Altman plot to determine the measure of agreement between the two methods. The mean GFR by iothalamate clearance was 110.6 ml/min/1.73 m and by the new Schwartz estimation 104.7 ml/min/1.73 m. The mean difference was 5.84 ml/min/1.73 m (95% CI 4.00–7.67). The newly purposed bedside Schwartz equation therefore demonstrated good agreement with the iothalamate renal clearances in our patient population and appears to be a valid bedside estimating equation for GFR in this sample of children. [ABSTRACT FROM AUTHOR]

The article presents several research on chronic kidney disease in children including "Overview of Pediatric Chronic Kidney Disease and End-Stage Renal Disease," by Sandra Watkins, "Epidemiological Approaches to the Study of Chronic Kidney Disease in Children," by Susan Furth, "North American Pediatric Renal Transplant Coordinating System and its Registry for Chronic Renal Insufficiency in Children," by William Harmon, "Growth," by Richard Fine, and "Neurodevelopment," by Debbie Gipson.

End-stage renal disease (ESRD) causes growth retardation in children, and poor growth has been linked to worse outcomes. Recombinant human growth hormone (rhGH) can increase growth velocity and final adult height in pediatric ESRD patients. We aimed to identify clinical predictors of short stature (height standard deviation score (Ht SDS) <−1.88) and rhGH use in short stature pediatric hemodialysis patients. In 2002, the Centers for Medicare & Medicaid Services (CMS) Clinical Performances Measures (CPM) ESRD Project collected demographic, clinical and laboratory data as well as rhGH use on all in-center hemodialysis patients in the US aged <18 years. The odds ratios (OR) of short stature and rhGH use for individual predictors were determined by multivariate logistic regression modeling. Six-hundred and fifty-one (92%) of 710 eligible patients were included for analysis. Of these, 266 (41%) had Ht SDS <−1.88. After adjustment, short stature was predicted by congenital / urologic causes of ESRD ((OR 5.4; 95% confidence interval [CI], 2.1–13.8; p <0.001) in patients aged 10–14 years; (OR 2.8; 95% CI, 1.5–5.4; p<0.01) in patients aged 15–18 years) and increasing years on dialysis ((OR 1.2; 95% CI, 1.1–1.4; p <0.01) in patients aged 10–14 years; (OR 1.2; 95% CI, 1.1–1.4; p <0.001) in patients aged 15–18 years). Of 266 short stature patients, 214 (80.5%) had data on rhGH use. Of these, 80 (37%) had been prescribed rhGH. After adjustment, use of rhGH in short-stature patients was predicted by white race (OR 2.1; 95% CI, 1.1–4.0; p <0.05), increasing years on dialysis (OR 1.13; 95% CI, 1.05–1.22; p <0.01) and patients with BMI <16.6 kg/m2 (OR 3.1; 95% CI, 1.2–8.4; p <0.05). Increasing age and level of intact parathyroid hormone were not associated with rhGH use among short stature patients. A significant proportion of pediatric hemodialysis patients have short stature. The majority of short-stature patients are not receiving rhGH. Patients with short stature who are white, have longer durations on dialysis and have lower BMI are more likely to receive rhGH. [ABSTRACT FROM AUTHOR]

The Centers for Medicare & Medicaid Services’ (CMS) end-stage renal disease (ESRD) Clinical Performance Measures (CPM) Project has collected data on all adolescent hemodialysis patients since 2000. Thus, by 2002 data were available on all adolescents on hemodialysis in the USA for 3 consecutive years. Possible associations between clinical parameters and linear growth in this cohort were evaluated. Ninety-four adolescents were on hemodialysis for the 3 study years. The mean height standard deviation score (ht SDS) fell from −1.97 to −2.36 over the 3 study years. Compared with patients with ht SDS ≥−1.88, patients with ht SDS <−1.88 in the 2002 study year ( n =53) were more likely to be male (66% vs 44%, p <0.05), on dialysis longer (6.9±4.5 years vs 4.1±2.3 years, p <0.001), and had lower height SDS in the 2000 study year (−2.90±1.31 vs −0.772±1.10, p <0.001). Patients with a ht SDS <−1.88 had a lower mean hemoglobin (11.4±1.6 g/dl vs 12.0±1.1 g/dl, p <0.05), but there were no differences in other clinical parameters. Among patients with ht SDS <−1.88, 38.8% ( n =20) were prescribed recombinant human growth hormone (rhGH) in the 2002 study year. There were no differences in demographic or clinical parameters between rhGH treated and untreated patients. Many adolescents who remain on hemodialysis have poor linear growth. Further evaluation is needed to delineate contributory factors and the possible underutilization of rhGH. [ABSTRACT FROM AUTHOR]

Iron therapy maintains iron stores and optimizes the response to recombinant human erythropoietin (r-HuEPO) in patients with end-stage renal failure. Information is limited, however, regarding the preferential route of iron administration in pediatric patients receiving hemodialysis. Therefore, we prospectively randomized 35 iron-replete patients (aged >1 to <20 years) to receive up to 16 weeks of maintenance IV (n=17) or daily oral (n=18) iron. Eligible patients had received hemodialysis for >2 months, had a baseline transferrin saturation [TSAT] >20%, and were receiving maintenance r-HuEPO. Treatment arms were evenly distributed with respect to baseline demographic and clinical characteristics, with no statistically significant differences in baseline hemoglobin (Hb), hematocrit (Hct), reticulocyte Hb content (CHr), serum ferritin (SF), TSAT, or r-HuEPO dose. In the 35 patients, IV iron dextran and not oral iron was associated with a significant increase (138.5 to 259.1 ng/ml, P=0.003) in SF. A comparison of the change in SF between the IV iron group and the oral iron group was also significant (P=0.001). Whereas only IV iron was associated with a significant decrease in the dose of r-HuEPO (234.0 to 157.6 U/kg per week, P=0.046) and an increase of the CHr (29.2 to 30.1 pg, P=0.049), these changes were not significantly different from those experienced by patients in the oral iron group. In both groups, the Hct remained stable and in neither group was there a significant change in the TSAT. In summary, although both oral and IV iron maintained patients in an iron-replete state in this short-term study, only IV therapy allowed for a significant improvement in iron stores. [ABSTRACT FROM AUTHOR]