Dramatic Decrease of Carnitine Esters after Interruption of Exogenous Carnitine Supply in Hemodialysis Patients

Abstract

L-carnitine supplementation is extensively used in patients on maintenance hemodialysis (HD) to improve dialysis-related clinical symptoms. In a series of studies, we investigated the dynamics of carnitine pool in carnitine-supplemented HD patients; here we report dramatic decrease with special changes of the ester profile due to interruption of the exogenous intake after the last HD session. Serum samples were collected from 18 L-carnitine-repleted end-stage renal disease (ESRD) patients before the L-carnitine supplementation, after completion of a carnitine supplementation period treatment (12 weeks, 1 g/IV/HD), right before the HD session, and 44 h after the dialysis. Levels of free carnitine (FC) and the individual esters were determined using electrospray MS/MS technique. Normally, L-carnitine supplementation causes significant elevation of all carnitine compounds to supraphysiological levels, which reaches a standard steady-state-like profile. In this study we found a dramatic decrease in the level of FC, and in short- and medium-chain acylcarnitines (ACs) 44 h after the last dialysis. At the end of this interdialytic period, FC levels increased to only 65% of the predialysis level, whereas the amounts of C2 and C3 esters recovered to only 50%. The level of C6 was 65% of the predialysis level, whereas the amount of C8 chain length ACs returned to 72% of the predialysis level. No significant change was seen in AC concentrations above C10 chain length. Omission of one single dosage of supplemental carnitine in long-term administration schemes results in dramatic decrease and reprofiling of carnitine esters even after the usual 44 h of interdialytic period.

• carnitine esters
• hemodialysis
• L-carnitine
• mass spectrometry

ACKNOWLEDGMENTS

The authors are grateful to Marta Hartung for her help in the technical management of the study, as well as to Sigma Tau for providing carnitine solutions.

Funding. This work was supported by OTKA: T73430, ETT: 497/2006, ETT 210-07/2009 and ÁOKKA 34039-6/2009.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.