Sequential change of asymmetric dimethylarginine levels after initiation of peritoneal dialysis in patients with end-stage renal disease

Background: We hypothesized that the asymmetric dimethylarginine (ADMA) metabolism in end-stage renal disease may be linked to the rate of protein turnover and to the vast pool of amino acids. In order to determine a correlation between the plasma levels of ADMA and the protein catabolic rate, we measured the ADMA levels as well as nutritional markers such as the normalized protein catabolic rate (nPCR) in patients with newly initiated continuous ambulatory peritoneal dialysis (CAPD). Methods: Twenty-four patients were recruited for this study. All patients were on the standard CAPD protocol, and followed for at least 1 year. Blood samples were collected at baseline before the initiation of peritoneal dialysis, and every 6 months for 1 year. The blood parameters studied included the serum albumin, total cholesterol, glucose, urea nitrogen, creatinine and ADMA. Peritoneal equilibrium test and measurements of weekly Kt/Vurea and nPCR were performed within 4 weeks of the blood sampling. Results: The change of ADMA levels over 1 year was positively correlated with that of haemoglobin (r = 0.592, P = 0.002) and nPCR during the same period (r = 0.508, P = 0.026). Conclusion: The findings of our study suggest that nPCR might influence the change of ADMA levels after initiation of CAPD.