Effect of hemodialysis session on the dynamics of carnitine ester profile changes in L-carnitine pretreated end-stage renal disease patients.

PURPOSE: Carnitine deficiency is common in end-stage renal disease (ESRD) patients receiving hemodialysis (HD) treatment. We investigated the effects of L-carnitine supplementation on acyl carnitine (AC) profile and the changes of distinct ACs during a single HD session in long-term L-carnitine pretreated ESRD patients.

METHODS: Twenty non-diabetic adult patients and 37 healthy controls were studied. Blood samples were drawn before and after 12 weeks of carnitine supplementation, then hourly during an HD session, as well as 30 min after the end of the session. Free and individual AC plasma levels were determined by using ESI MS/MS technique.

RESULTS: HD patients showed lower free- and total carnitine levels and elevated ACs and acyl/free carnitine ratio before carnitine supplementation. The L-carnitine supplementation resulted in dramatic elevation of all carnitine esters. The HD session induced a progressive decline in free, short-chain, and dicarboxylic ACs (~80 % of pre-HD amount was washed out); the decrease of medium-chain ACs proved to be more moderate (~60 % washed out), whereas the long-chain ACs remained unaffected. Already 30 min after HD, a substantial increase was seen in free carnitine concentration (reaching 26 % of predialysis level) and the ACs also started to replenish (to 21-52 % of predialysis levels), without further exogenous carnitine load.

CONCLUSIONS: The washout induced by HD session results in variable depletion of short-, medium-, and long-chain carnitine esters in carnitine-pretreated patients; the recovery of the circulating carnitine esters from the body stores occurs within 30 min after the cessation of the HD procedure.