PROTEIN AND LIPID-METABOLISM IN NEPHROTIC INFANTS ON PERITONEAL-DIALYSIS AFTER NEPHRECTOMY

Congenital nephrotic syndrome of the Finnish type (CNF) is associated with protein deficiency despite substantial protein supplementation in the nephrotic state before nephrectomy. Different protein intakes (2. 5 vs. 3.7 g/kg per day) in hypoproteinaemic children on continuous cyc ling peritoneal dialysis (CCPD) were studied. Lipids were also measure d to determine whether severe atherogenic abnormalities seen during ne phrosis improved after nephrectomy. Growth was normal or became normal with both protein intakes. Serum pre-albumin and transferrin concentr ations became normal. Total protein (57 +/- 3.0 vs. reference limits 6 0 - 75 g/l) and albumin (28 +/- 5.0 vs. reference limits 30-50 g/l) co ncentrations improved but remained below normal, even with the higher protein intake. Muscle mass determined by measuring femoral quadriceps muscle thickness using ultrasound was markedly reduced in all patient s at nephrectomy. It improved (P < 0.05) in all but 2 patients who had several bacterial infections, but reached normal level in only 3 pati ents within 6 months. Plasma total, very low-density lipoprotein (VLDL ) and low-density lipoprotein (LDL) triglyceride concentrations decrea sed (P < 0.05, P < 0.05 and P < 0.01, respectively) and VLDL, LDL and high-density lipoprotein (HDL) particles contained less triglyceride t han in the nephrotic state. HDL cholesterol concentrations increased b y 28% [0.58 +/- 0.22 mmol/l during nephrosis, 0.81 +/- 0.21 mmol/l on CCPD after nephrectomy (P < 0.05)] but remained below the level of 1.3 8 +/- 0.75 mmol/l in normal controls (P < 0.001). If compared with con trols there were still significant abnormalities in lipoprotein concen trations on CCPD. Hence, a protein intake of 2.5 g/kg per day represen ting 140% of the recommended dietary allowance is sufficient to mainta in normal growth and improve nutritional and protein status in CNF pat ients on CCPD. Although lipid levels improved they remained abnormal.