Circulating fibroblast growth factor 23 in children on peritoneal dialysis is associated with effective dialysis.

Our purpose was to assess the relationship between serum fibroblast growth factor 23 (FGF23) and left ventricular function, carotid intima-media thickness (CIMT) and laboratory features in children on peritoneal dialysis (PD). The study population consisted of 17 patients (11 female; median age 7.83 years, range 0.66-17.75) undergoing PD for 22 months (range 2-98). Serum FGF23, serum phosphorus, calcium, intact parathyroid hormone (iPTH), 25(OH) vitamin D, 1,25(OH)2 vitamin D and Kt/V urea, left ventricular mass (LVM) and LVM index (LVMI) were assessed. Median FGF23 level was 29.92 pg/ml (22.7-74.76), phosphorus was 5.2 mg/dl (3.1-9.9), iPTH was 438 pg/ml (16-1446), 25(OH) vitamin D was 11 ng/ml (5-35), 1,25(OH)2 vitamin D was 11 pg/ml (2-106), Kt/V urea was 2.33 (1.01-3.84). FGF23 level was independently associated with Kt/V urea (p<0.001). We found that effective dialysis may be the leading determinant of FGF level, independent from the calcium-phosphorus-PTH axis, in pediatric PD patients.

Malondialdehyde, antioxidant enzymes, and renal tubular functions in children with iron deficiency or iron-deficiency anemia.

We aimed to investigate the effects of iron deficiency (ID) or iron-deficiency anemia (IDA) on oxidative stress and renal tubular functions before and after treatment of children. A total of 30 children with a diagnosis of IDA constituted the IDA group and 32 children with a diagnosis of ID constituted the ID group. Control group consisted 38 age-matched children. Serum ferritin, soluble transferrin receptor (sTfR), serum, and urinary sodium (Na), potassium (K), calcium (Ca), phosphorus (P), creatinine (Cr), uric acid (UA), urinary N-acetyl-ß-D-glucosaminidase (NAG) levels, and intra-erythrocyte malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) levels were measured before and after iron therapy in the IDA and ID groups, whereas it was studied once in the control group. We have divided the study group in groups according to age (infants <2 years, children 3-9 years, and adolescents 10-15 years). Patients with IDA (infant, adolescent) and ID (infant, children, and adolescent) had a significantly high level of MDA in post-treatment period in comparison to those of healthy control. Patients with IDA (children, adolescent) and ID (infant, children) had a significantly high level of pre-treatment GSH-Px than controls. Post-treatment SOD was lower in IDA (children and adolescent) groups than control and post-treatment CAT was lower in IDA and ID (adolescent) groups than control. These findings show that ferrous sulfate used in the treatment of ID or IDA could lead to oxidative stress; however, a marked deterioration of in proximal renal tubular functions was not seen.

Evaluation of lipid peroxidation and antioxidant system in healthy iron-replete infants receiving iron prophylaxis.

OBJECTIVE: Iron supplementation is commonly recommended for infants; however, there are some reports that it causes oxidative damage. The aim of this study was to investigate the potential effects of iron supplementation at 4 mo of age, for a period of 2 mo, on lipid peroxidation and free radical scavenging enzymes. METHODS: Twenty-seven healthy 4-mo-old infants chosen randomly and given iron supplementation (ferrous sulfate, 10 mg of elemental iron per day) constituted the study group and 26 healthy 4-mo-old infants who were chosen randomly and not given iron supplementation constituted the control group. Weight, height, head circumference, complete blood cell count, serum ferritin level and intraerythrocytic zinc, iron, copper, malondialdehyde, catalase, superoxide dismutase, and glutathione peroxidase levels were measured in the two groups at 4 and 6 mo of life. RESULTS: Compared with controls at 6 mo of age, no significant differences were observed for intraerythrocytic zinc (0.5 ± 0.1 versus 0.6 ± 0.2 µg/mL, P > 0.05), copper (0.2 ± 0.1 versus 0.2 ± 0.2 µg/mL, P > 0.05), iron (130.8 ± 10.9 versus 127.4 ± 11.1 µg/mL, P > 0.05), malondialdehyde (21.4 ± 3.5 versus 22.4 ± 2.3 nmol/g of hemoglobin, P > 0.05), catalase (135.4 ± 23.9 versus 135.1 ± 23.3 MU/g of hemoglobin, P > 0.05), superoxide dismutase (1736.4 ± 141.1 versus 1701.3 ± 103.9 U/g of hemoglobin, P > 0.05), and glutathione peroxidase (8.9 ± 1.6 versus 8.4 ± 1.6 U/g of hemoglobin, P > 0.05) levels. CONCLUSION: Our study indicates that the supplemental use of elemental iron 10 mg/d for a period of 2 mo in healthy iron-replete infants did not cause lipid peroxidation or an impairment of antioxidant status.