The influence of dialysis membrane upon protein catabolic rate.

It has been hypothesized that the protein catabolic rate (PCR) is dependent upon the amount [Kt/V (urea)] and the type of dialysis (synthetic vs. cellulosic membrane). In an ongoing multicenter study comparing short hour-high flux with conventional cellulosic dialysis, 49 patients have completed 6 months and serial urea kinetic data has been obtained. Of the 49, 28 were on AN69S membrane dialyzers, and 21 on cellulosic. The patients on AN69S received significantly less Kt/V than those on cellulosic dialyzers (0.97 +/- 0.3 vs. 1.20 +/- 0.2; p = 0.0016), yet attained similar PCRs (1.07 +/- 0.2 vs. 1.02 +/- 0.1, NS). Significant (p = 0.002) linear relationships between PCR and Kt/V (urea) were found, yet the line slopes were higher for AN69S (average 0.46) than cellulose (average 0.25). Patients on AN69S achieve the same PCR for less Kt/V than patients on cellulosic dialyzers, supporting the hypothesis.