CREATININE KINETIC MODELING - A SIMPLE AND RELIABLE TOOL FOR THE ASSESSMENT OF PROTEIN NUTRITIONAL-STATUS IN HEMODIALYSIS-PATIENTS

While the mathematical modelling of urea kinetics is in wide use for e valuating treatment adequacy and protein nutrition in dialysis patient s, the kinetics of creatinine generation in dialysis patients has been relatively unexplored. In this study creatinine kinetic modelling as a clinical tool was investigated in a group of 90 patients treated by haemodialysis (n=20), haemodiafiltration (60), haemofiltration (7), or biofiltration (3) over a 6-36-month period. A single pool model of cr eatinine kinetics was employed to obtain monthly values of creatinine distribution space and creatinine appearance rate. Extrarenal creatini ne degradation rate, estimated using a clearance of 0.038 l/kg/24 h as suggested by Mitch and co-workers, was added to creatinine appearance rate in urine and dialysate to calculate a corrected creatinine index (CI). Extrarenal degradation accounted for 12+/-2% of CI. CI was high er in males (22.4+/-4.5 mg/kg/24 h) than females (19.8+/-4.8) and decr eased with age, falling off more sharply for the female group (CI=29.9 -0.185 . age, R=0.72) than the males (CI=24.1-0.030 . age, R=0.31). CI was found to correlate strongly with protein catabolic rate determine d by mea kinetic modelling (CI=8.84+10.91 . PCR). Low or reduced CI wa s associated in this study group with severe malnutrition status and h igh mortality rate. CI is suggested as a strong predictor of patient m orbidity and mortality.