Residual renal function and nutrition in young patients on chronic hemodialysis

Residual renal function (RRF) has been associated with a better nutritional status in adult patients on chronic dialysis, but there is as yet no data available for young patients on chronic hemodialysis (HD). We have retrospectively analyzed 3-day dietary reports and simultaneous urea kinetic monitoring data (n = 179) of 30 children, adolescents and young adults on chronic HD. The protein catabolic rate (PCR) was calculated and normalized by body weight (nPCR). The HD dialysis dose (Kt/VHD), RRF (calculated by urea clearance, Ku, and expressed as residual Kt/V) and total Kt/V (Kt/Vtot) were evaluated. In all patients, nPCR was correlated with dietary protein intake (nDPI) (p < 0.0001) and Kt/Vtot (p < 0.0001) but not with Kt/VHD (p = 0.11). In patients with RRF, Ku was associated with nPCR (p < 0.0001), while Kt/VHD was not (p = 0.10), and nPCR was higher than in patients without RRF (1.46 +/- 0.41 vs. 1.03 +/- 0.33 g/kg/day; p < 0.0001). Patients on recombinant growth hormone (rhGH) treatment showed higher nPCR values than those without rhGH (1.34 +/- 0.41 vs. 1.01 +/- 0.39 g/kg/day; p < 0.0001). In a multiple regression model including age, rhGH treatment, RRF, Kt/Vtot and Kt/VHD, and nPCR showed the best correlation with RRF (beta = 0.128; p < 0.0001). In conclusion, in children, adolescents and young adults on chronic HD treatment, RRF positively affects nutrition independently of HD efficiency and rhGH treatment.