Association between Increases in Normalized Protein Catabolic Rate and Increases in Creatinine Generation Rate in Dialysis Patients

The older dialysis population is growing, and malnutrition and wasting syndrome are great concerns in this population. The management of these syndromes includes appropriate nutritional intake and physical activity. However, whether management in the form of an increase in protein intake has a beneficial effect on muscle mass has not been demonstrated. In this study, we investigated an association between changes of normalized protein catabolic rate (nPCR), as a proxy for protein intake and percent creatinine generation rate (%CGR), as a proxy for muscle mass in patients receiving hemodialysis. Multiple linear regression models were employed, and we included several sensitivity analyses. The results showed that increases in nPCR were associated with increases in %CGR. The association was stronger in patients with baseline %CGR levels below 100%. This was the first study to demonstrate that an increase in dietary protein intake might increase the muscle mass, but this study had certain limitations. Future interventional studies will be needed to investigate whether increases in protein intake have a beneficial effect on sarcopenia, protein-energy wasting, and frailty.