Carnitine Depletion During Chronic Hemodialysis: Effect of Substitution on Free Carnitine Plasma Levels

Abstract

Carnitine plays a role in the oxidative metabolism of free fatty-acids by transporting long chain fatty acids into the mitochondrial matrix (1). During chronic hemodialysis, a depletion of plasma carnitine levels has been observed and attributed to dialysis of this unbound low-molecular weight substance (M.W. 161) (2, 3). Due to the high efficiency of the presently used dialyzers, this may lead to long term carnitine depletion in the vascular and muscular compartments. Moreover, it appears that the synthesis of carnitine is altered in dialysis patients (4). Since some of the complications seen during chronic hemodialysis have been attributed to a depletion in carnitine, substitution by carnitine i.v. or in the dialysate has been logically applied. It appears however that a mixture of D, L-carnitine can lead to a myasthenia like syndrome due to the presence of D-carnitine (5). The aim of the present study was to evaluate the evolution of free carnitine plasma levels in a population of chronic hemodialysis patients before, during and after substitution with L-carnitine i.v. during 8 weeks.