The aim of this work was to assess the effect of recombinant human growth hormone (rhGH) on the kinetics of urea and creatinine and selected indices of dialysis adequacy in children with end-stage renal failure treated with peritoneal dialysis. We studied 24 children on peritoneal dialysis, including 10 children aged 9-15.7 years (mean age 12.5 years) treated with 1-1.1 IU/kg/week of rhGH administered daily for 6 months. The control group included 14 patients aged 5.4-18.3 years (mean age 12.6 years). Kinetic modelling of urea and creatinine using Adequest was performed in all patients at baseline and after 3 and 6 months of follow-up. Total dialysate and urinary excretion of urea and creatinine (tUE and tCE, mg/min), total urea and creatinine clearance (tUC and tCC, L/week), weekly Kt/V, normalized total weekly creatinine clearance (ntCC, L/week/1.73 m2), total body water (TBW, kg), and absolute and percent change of TBW (DTBW, kg, and D%TBW, respectively) were calculated. Albumin level was measured and diet composition was analysed in all patients. Insignificant decrease in Kt/V was found after 3 and 6 months of rhGH treatment despite stable values of tUC (45.3 +/- 15 L/week vs 45.6 +/- 15 L/week, p = NS). Serum creatinine increased from 7.38 +/- 1.52 to 9.26 +/- 2.98 mg/dL after 6 months of rhGH treatment. Significantly higher values of delta %TBW were found among treated patients compared to the control group (1.23 +/- 0.7 kh vs 0.57 +/- 0.7 kg, P < 0.05). delta TBW in patients treated with rhGH was significantly higher during months 0-3 compared to months 3-6 (0.85 +/- 0.6 kg and 0.38 +/- 0.17 kg, respectively, p < 0.05). No significant changes in ntCC, albumin concentration and diet composition were found.
Conclusions: 1. A trend to lower urea values in children treated with peritoneal dialysis was found after 3 months of rhGH treatment. Concomitant decrease in Kt/V may have resulted from increased TBW. 2. An increase in creatinine level was observed during rhGH treatment in children treated with peritoneal dialysis. Decrease in normalized total creatinine clearance (ntCC) and normalized dialysate creatinine clearance (ndCC) during rhGH treatment may have resulted from increased serum creatinine and not from decreased creatinine excretion. 3. Treatment with rhGH in children on peritoneal dialysis makes it difficult to interpret commonly used indices of dialysis adequacy such as Kt/V and ntCC.