Malnutrition and loss of appetite remain a frequent problem in children with chronic renal failure (CRF). Recent studies in human gave much attention for leptin, polypeptide produced by adipocytes, and its influence on appetite and energetic balance regulation. The study aimed at evaluation of serum leptin levels (SLL) in children with CRF with regard to applied method of treatment. Study included 29 children, mean age 13.9 +/- 4.2 years. Among them 10 on peritoneal dialysis (PD, mean age 11.9 +/- 4.3 years), 10 - on maintenance hemodialysis (HD, mean age 16.3 +/- 2.4 years), 9 - on conservative treatment of CRF (CT, 13.0 +/- 4.3 years). SLL was evaluated by RIA. In all groups of children with CRF SLL was high: group I (PD): 34.3 +/- 44.0, group II (HD): 31.5 +/- 57.4, group III (CT): 16.5 +/- 21.1 ng/ml. There was no difference of SLL in children with CRF regarding to method of treatment. Evaluated SLL/BMI index (body mass index) showed no difference in comparison of examined groups of children with CRF (values respectively: PD: 1.5 +/- 1.8; HD: 1.3 +/- 2.1; CT: 0.8 +/- 1.9 ng/ml +/- kg/m2). Also SLL/creatinine index did not differ between examined groups (values respectively: PD: 5.2 +/- 8.2; HD: 4.4+/-8.4; CT: 4.0 +/- 4.6 ng/mg). In both subgroups on dialysis treatment SLL correlated with BMI, additionally in HD SLL correlated with body weight, in PD - with serum ionised calcium. No correlation with age, dialysis treatment duration, creatinine and urea levels was found.
Conclusions: In children on maintenance dialysis high SLL were observed. The highest SLL in PD patients, when considering CRF group could be related to high dialysate glucose concentration and probably decreased clearance through the peritoneal membrane. The correlation between SLL and BMI was preserved in all groups of children with CRF, irrespective of applied method of treatment.