Changes of plasma free choline and choline-containing compounds’ concentrations and choline loss during hemodialysis in ESRD patients

Objectives: This study was undertaken to determine the changes in plasma free choline and choline-containing compounds in end stage renal disease (ESRD) and to determine if they were lost into the dialysate during hemodialysis. Design and methods: Plasma and dialysate free choline, phosphocholine and phospholipid-, phosphatidylcholine-, sphingomyelin-bound choline were measured before, during and after hemodialysis. Results: Plasma free and bound choline concentrations (mean ± standard error of the mean) were 12.9 ± 0.6 and 2697 ± 57 μM or 37.3 ± 0.9 and 2792 ± 98 μM in controls or in ESRD patients, respectively. Free choline concentrations were correlated (r = 0.598; p < 0.001) with the time the patients were subjected to hemodialysis. Plasma free choline and phosphocholine concentrations are decreased by a total of −8.1 ± 0.6 μmol/L and −88 ± 8 μmol/L, respectively; phospholipid-, phosphatidylcholine- and sphingomyelin-bound choline are increased, during hemodialysis. Patients lost about 350 μmoles of choline into the dialysate during hemodialysis. Conclusion: Plasma free choline concentrations are elevated in ESRD, and a considerable amount of choline is lost into the hemodialysate.