Dietary protein intake and long-term outcomes after kidney transplantation

Protein intake is an important part of any diet. For patients that received a kidney transplantation, it is yet unknown what the optimal quantity and quality of protein intake is. In this thesis, we aimed to investigate several aspects of protein intake after kidney transplantation and their associations with long-term outcomes. Through observational, prospective cohort studies, we found that higher protein intake is associated with longer patient and graft survival compared to low protein intake, likely through a multifactorial pathway, which includes preservation of muscle mass and physical fitness. A relatively high urinary excretion of biomarkers for white and red meat intake was found to be associated with lower risk of long-term graft failure. Protein intake provides amino acids as building blocks, but also amino acids that can be used as substrate for production of other molecules, including nitric oxide (NO) and hydrogen sulfide (H2S). These molecules have various effects in various organs and biological systems. We studied the waste products of these molecules in the urine of patients and found that high urinary excretion of these waste products is associated with longer patient and graft survival. The results of this thesis suggest that patients should not have a low protein diet after kidney transplantation and that a relatively high protein intake may be advantageous for long-term survival. However, before we can determine the optimal quantity and quality of protein intake, more experimental research is needed. The results of this thesis may serve as a scientific base for this research.

Dissertation: http://hdl.handle.net/11370/53219a8c-a270-4ec9-9a34-a0ec0d7745a7