NDT Advance Access originally published online on November 29, 2007
Nephrology Dialysis Transplantation 2008 23(4):1330-1335; doi:10.1093/ndt/gfm793
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Guanidino compounds after creatine supplementation in renal failure patients and their relation to inflammatory status
1 Laboratory Clinical Chemistry, University Hospital Ghent 2 Laboratory of Neurochemistry and Behavior, University of Antwerp, Institute Born-Bunge, Antwerp 3 Renal Unit, Department of Internal Medicine, Algemeen Ziekenhuis St Jan, Brugge 4 Renal Unit, Department of Internal Medicine, University Hospital Ghent, Belgium
J. Delanghe, Laboratory Clinical Chemistry 2P8, University Hospital Ghent, De Pintelaan 185, 9000 Ghent, Belgium. Tel: +32-9-240-29-56; Fax: +32-9-240-49-85; E-mail: Joris.Delanghe{at}UGent.be
| Abstract |
|---|
Background. Specific guanidino compounds have been described as uraemic toxins and their concentrations are increased in renal failure due to dimished glomerular filtration, whereas the guanidino compound creatine is used as a performance-enhancing substance in athletes. The present study investigates the effects of creatine supplementation on plasma guanidino compounds in a chronic haemodialysis population.
Methods. Twenty male haemodialysis patients were included in a placebo-controlled cross-over trial. Patients were treated with creatine (2 g/day) or placebo during two treatment periods of 4 weeks, separated by a washout of 4 weeks. Plasma guanidino compounds and routine biochemical parameters were determined, as well as the prognostic inflammatory and nutritional index (PINI).
Results. Upon creatine supplementation, guanidinoacetate concentrations decreased by 15%, due to inhibition of creatine synthesis. Concentrations of
-keto-
-guanidinovaleric acid increased three-fold and argininic acid concentrations doubled. Guanidinosuccinate concentrations did not change, but correlated inversely with CRP (r = –0.736; P = 0.001), PINI-score (r = –0.716; P = 0.002) and correlated positively with plasma urea concentration (r = 0.54; P = 0.02).
Conclusions. Creatine supplementation in haemodialysis patients significantly altered the concentration of specific guanidino compounds. Guanidinosuccinate correlated positively with plasma urea and negatively with inflammation markers.
Keywords: creatine; guanidino compounds; neurotoxins; urea cycle
Received for publication: 16. 8.07
Accepted in revised form: 11.10.07