The metabolic response to ingested protein is normal in long-term hemodialysis patients

Background Protein-energy malnutrition affects 30% to 50% of hemodialysis (HD) patients. This has been attributed to inadequate food intake, but may be caused by disturbances in utilization of ingested protein. Methods: We studied protein kinetics during fasting and during ingestion of a protein-enriched meal to investigate possible metabolic differences between stable HD patients and control subjects. Whole-body protein kinetics was measured by means of a primed constant infusion of L[1-C-13] valine. Results: During fasting, whole-body protein balance was significantly less negative in HD patients compared with control subjects. During meal intake, protein balance was similar between HD patients and control subjects. Meal intake increased protein balance significantly in both groups, but not differently between the groups. Also, protein oxidation was decreased during fasting in HD patients compared with control subjects, but not during meal intake. Conclusion: We conclude that the rate of protein breakdown is lower in HD patients compared with control subjects, but the efficiency of protein utilization is normal in HD patients during a nondialysis day.