Dialysis modality-dependent changes in serum metabolites: accumulation of inosine and hypoxanthine in patients on haemodialysis.
BACKGROUND
The body metabolism of patients with end-stage renal disease may be altered in response to long-term dialysis treatment. Moreover, the pattern of serum metabolites could change depending on the type of dialysis modality used. However, dialysis modality-dependent changes in serum metabolites are poorly understood. Our aim was to profile comprehensively serum metabolites by exploiting a novel method of (1)H-NMR-based metabonomics and identify the differences in metabolite patterns in subjects receiving haemodialysis (HD) and peritoneal dialysis (PD).


METHODS
Anuric and non-diabetic HD patients were matched to PD patients for age, sex and dialysis duration. Accurate concentrations of serum metabolites were determined using the target-profiling procedure, and differences in the levels of metabolites were compared using multivariate analysis.


RESULTS
Principal Components Analysis score plots showed that the metabolic patterns could be discriminated by dialysis modalities. Hypoxanthine and inosine were present only with HD, whereas serum xanthine oxidase activity and uric acid levels were not different. In contrast, PD was associated with higher levels of lactate, glucose, maltose, pyruvate, succinate, alanine, and glutamate linked to glucose metabolism and the tri-carboxylic acid cycle. Maltose appeared only in patients using icodextrin solution for PD. Known uraemic retention solutes such as urea, creatinine, myo-inositol and trimethylamine-N-oxide were increased in both dialysis groups.


CONCLUSIONS
Metabonomics shows apparent differences in the profiles of serum metabolites between HD and PD, which were influenced by dialysis-related processes. Inosine and hypoxanthine are present only in HD patients, which is likely to represent more hypoxic and oxidative stress.
Choi
Ji-Young
JY
Division of Nephrology, Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea.
Yoon
Yoo Jeong
YJ
Choi
Hee-Jeong
HJ
Park
Sun-Hee
SH
Kim
Chan-Duck
CD
Kim
In-San
IS
Kwon
Tae-Hwan
TH
Do
Jun-Young
JY
Kim
Sung-Ho
SH
Ryu
Do Hyun
DH
Hwang
Geum-Sook
GS
Kim
Yong-Lim
YL
D016022:Case-Control Studies; D003404:Creatinine / Q000097:blood; D005260:Female; D006801:Humans; D019271:Hypoxanthine / Q000097:blood*; D007288:Inosine / Q000097:blood*; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000628:therapy*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D055432:Metabolomics; D008875:Middle Aged; D010530:Peritoneal Dialysis; D025341:Principal Component Analysis; D006435:Renal Dialysis; D014969:Xanthine Oxidase / Q000097:blood
D019271:Hypoxanthine; D007288:Inosine; D003404:Creatinine; D014969:Xanthine Oxidase