title: The effects of oral L-carnitine supplementation on physical capacity and lipid metabolism in chronic hemodialysis patients.
abstract: BACKGROUND
  It is well known that the physical activity in chronic hemodialysis patients decreases compared to that in normal subjects. In order to investigate the effects of L-carnitine on physical capacity and lipid metabolism, a cardiopulmonary exercise test using a bicycle ergometer was performed before and after 3 months of oral L-carnitine supplementation under double-blind conditions.
  
  
  RESULTS
  A total of 20 stable outpatients undergoing hemodialysis treatment were randomly divided into 2 groups: controls receiving placebo and patients receiving 900 mg L-carnitine p.o. daily. The levels of free and acyl carnitine increased significantly from 22.9 ± 7.3 to 149.9 ± 51.8 μmol/l and from 16.0 ± 2.8 to 100.3 ± 50.2 μmol/l, respectively, in the L-carnitine group; however, there was no significant change in other plasma lipid profiles. The exercise time was decreased and the heart rate at the anaerobic threshold was increased in the control group 3 months after the study period, but there were no such changes observed in the L-carnitine group. The minute ventilation/CO2 output slope increased significantly from 38.9 ± 7.8 to 43.8 ± 11.8 in the L-carnitine group. It has been speculated that a shift in the energy source occurs from carbohydrate to lipid, in terms of an increase of oxygen demand.
  
  
  CONCLUSIONS
  L-Carnitine supplementation might have some beneficial effects on the physical capacity of chronic hemodialysis patients due to the improvement of the lipid metabolism in the muscle.
authors.affiliation: Kidney Center, Sapporo South One Hospital, Sapporo, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kudoh
authors.affiliation: Kidney Center, Sapporo South One Hospital, Sapporo, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Aoyama
authors.affiliation: Kidney Center, Sapporo South One Hospital, Sapporo, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Torii
authors.affiliation: Kidney Center, Sapporo South One Hospital, Sapporo, Japan.
authors.forename: Qijie
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Kidney Center, Sapporo South One Hospital, Sapporo, Japan.
authors.forename: Daigo
authors.initials: D
authors.lastname: Nagahara
authors.affiliation: Kidney Center, Sapporo South One Hospital, Sapporo, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Sakata
authors.affiliation: Kidney Center, Sapporo South One Hospital, Sapporo, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Nozawa
keywords: Exercise test; Hemodialysis; L-Carnitine; Physical capacity