title: 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.
authors.affiliation: Department of Medical Genetics, Clinical Center, University of Pécs, Pécs, Hungary. judit.bene@aok.pte.hu
authors.forename: Judit
authors.initials: J
authors.lastname: Bene
authors.forename: Botond
authors.initials: B
authors.lastname: Csiky
authors.forename: Istvan
authors.initials: I
authors.lastname: Wittmann
authors.forename: Endre
authors.initials: E
authors.lastname: Sulyok
authors.forename: Bela
authors.initials: B
authors.lastname: Melegh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002331:Carnitine / Q000008:administration & dosage / Q000493:pharmacokinetics*; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004734:Energy Metabolism / Q000187:drug effects*; D004952:Esters; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D012189:Retrospective Studies; D053719:Tandem Mass Spectrometry; D014803:Vitamin B Complex / Q000008:administration & dosage / Q000493:pharmacokinetics
chemical_list: D004952:Esters; D014803:Vitamin B Complex; D002331:Carnitine