The protein catabolic rate as a measure of protein intake in dialysis patients: usefulness and limits.
To test the validity of the determination of protein catabolic rate (PCR) as a measure of protein intake in dialysis patients, we studied a selected population of 27 well-dialysed patients, free of catabolic illnesses, and in apparent clinical stability. Daily protein intake, obtained by controlled dietary records, and protein catabolic rate, measured by urea kinetic modeling, were 1.02 +/- 0.26 and 0.99 +/- 0.16 g/kg respectively. Although there was a good correspondence between protein intake and protein catabolic rate in many of our patients, in the six cases with dietary protein content less than 0.8 g/kg, protein catabolic rate was regularly greater than 0.8 g/kg; on the contrary, in four patients ingesting more than 1.2 g/kg of protein, protein catabolic rate values were significantly less than protein intake. Our results demonstrate that some degree of nitrogen imbalance may be present in about 25% of clinically stable dialysis patients, and suggest that current concepts of clinical stability do not imply a stable metabolic state in a substantial portion of dialysis patients. Therefore, protein catabolic rate determination does not provide a reliable index of protein intake in many dialysis patients.
Panzetta
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Divisione Clinicizzata di Nefrologia e Istituto di Chimica e Microscopia Clinica, Università di Verona, Italia.
Tessitore
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Faccini
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Maschio
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D000328:Adult; D000368:Aged; D001806:Blood Urea Nitrogen; D004044:Dietary Proteins / Q000008:administration & dosage*; D002149:Energy Intake; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011506:Proteins / Q000378:metabolism*; D006435:Renal Dialysis
D004044:Dietary Proteins; D011506:Proteins