CARNITINE LOSSES IN HEMODIALYSIS - INFLUE NCE OF DIFFERENT MEMBRANE-DIALYZERS AND RELATIONSHIP WITH NUTRITIONAL-STATUS

In patients undergoing maintenance hemodialysis, free carnitine is fre quently low in plasma but acylcarnitines may be elevated. These carnit ine abnormalities have been associated with some disorders in hemodial ysis patients, such as lipid metabolism, skeletal and myocardial muscl e function, posthemodialysis asthenia, cramps and nutritional status. The effect of carnitine supplementation in these patients is controver sial. The aim of this study, was to determine the losses of carnitine during hemodialysis sessions, with different membranes and their relat ionship with malnutrition. In 39 patients, aged between 28 and 71 year s, 21 males and 18 females, stable on hemodialysis for a period betwee n 6 months and 12 years, free carnitine and acylcarnitines were determ ined in plasma and their clearances measured during hemodialysis and c ompared to creatinine and urea clearances with different membranes: ce llulosic 12 patients, AN69 13, polysulfone 8 and cellulose triacetate 6 patients. Dialysis tolerance, nutritional status, biochemical and an thropometric indicex and urea kinetics were studied. Free-carnitine wa s decreased, 31,9 +/- 1,48 nM/ml. Short-chain acylcarnitines were elev ated in plasma 19,5 +/- 1,32 nM/ml. Carnitine clearances with high-per meability membranes were significantly higher than with cellulosic one s, about > 30 % carnitine losses per hemodialysis with highs-permeabil ity dialyzers (1,6-1,8 m(2)) were calculated as microM and with cellul ose dialysers in 685 microM. Nine out of 39 patients showed severe mal nutrition. The best predictors of malnutrition were: MAMC, serum album in, PCR. Free-carnitine correlates significantly with: PCR/KtV, PCR, s erum albumin. Free-carnitine was decreased in all patients with a poor nutritional status. High losses of carnitine and low protein supply m ay lead to chronic negative carnitine balance and may be associated wi th malnutrition.