title: Accumulation of trimethylamine and trimethylamine-N-oxide in end-stage renal disease patients undergoing haemodialysis.
abstract: BACKGROUND
  Trimethylamine (TMA) is a short-chain tertiary aliphatic amine that is derived from the diet either directly from the consumption of foods high in TMA or by the intake of food high in precursors to TMA, such as trimethylamine-N-oxide (TMNO), choline and L-carnitine. The clinical significance of TMA may be related to its potential to contribute to neurological toxicity and 'uraemic breath' in patients with end-stage renal disease (ESRD).
  
  
  METHODS
  Concentrations of TMA and TMNO in plasma from 10 healthy adults (not on haemodialysis) and 10 adults with ESRD undergoing haemodialysis (pre- and post-dialysis) were determined by gas chromatography-mass spectrometry.
  
  
  RESULTS
  The concentrations of TMA and TMNO in pre-dialysis plasma (1.39+/-0.483 and 99.9+/-31.9 microM, respectively) were significantly (P<0.05) higher than the corresponding levels in healthy subjects (0.418+/-0.124 and 37.8+/-20.4 microM, respectively). However, there were no significant differences between post-dialysis and healthy subject plasma concentrations. In the ESRD patients, there was a significant (P<0.05) reduction in plasma TMA (from 1.39+/-0.483 to 0.484+/-0.164 microM) and TMNO (from 99.9+/-31.9 to 41.3+/-18.8 microM) during a single haemodialysis session.
  
  
  CONCLUSIONS
  TMA and TMNO accumulate between haemodialysis sessions in ESRD patients, but are efficiently removed during a single haemodialysis session.
authors.affiliation: Centre for Pharmaceutical Research, University of South Australia, Adelaide, SA 5000, Australia. marcus.bain@unisa.edu.au
authors.forename: Marcus A
authors.initials: MA
authors.lastname: Bain
authors.forename: Randall
authors.initials: R
authors.lastname: Faull
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Fornasini
authors.forename: Robert W
authors.initials: RW
authors.lastname: Milne
authors.forename: Allan M
authors.initials: AM
authors.lastname: Evans
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000175:diagnosis / Q000628:therapy*; D007677:Kidney Function Tests; D008297:Male; D008744:Methylamines / Q000097:blood / Q000378:metabolism*; D008875:Middle Aged; D011336:Probability; D012016:Reference Values; D006435:Renal Dialysis / Q000009:adverse effects / Q000379:methods*; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D008744:Methylamines; C005855:trimethyloxamine; C023336:trimethylamine