title: Plasma metabolomic profiles in different stages of CKD.
abstract: OBJECTIVE
  CKD is a common public health problem. Identifying biomarkers adds prognostic/diagnostic value by contributing to an understanding of CKD at the molecular level and possibly defining new drug targets. Metabolomics provides a snapshot of biochemical events at a particular time in the progression of CKD. This cross-sectional metabolomics study ascertained whether plasma metabolite profiles are significantly different in CKD stages 2, 3, and 4.
  
  
  METHODS
  An analysis of plasma metabolites, using gas and liquid chromatography coupled to mass spectrometry, was conducted on 30 nondiabetic men ages 40-52 years, with 10 participants each in CKD stages 2, 3, and 4 based on their estimated GFR (calculated by the Modified Diet in Renal Disease formula). Participants were recruited in late 2008, and plasma samples were tested at Metabolon Inc and analyzed in 2012.
  
  
  RESULTS
  Comparison of stage 3/stage 2 identified 62 metabolites that differed (P ≤ 0.05), with 39 higher and 23 lower in stage 3 compared with stage 2; comparisons of stage 4/stage 2 identified 111 metabolites, with 66 higher and 45 lower; and comparisons of stage 4/stage 3 identified 11 metabolites, with 7 higher and 4 lower. Major differences in metabolite profiles with increasing stage of CKD were observed, including altered arginine metabolism, elevated coagulation/inflammation, impaired carboxylate anion transport, and decreased adrenal steroid hormone production.
  
  
  CONCLUSIONS
  Global metabolite profiling of plasma uncovered potential biomarkers of stages of CKD. Moreover, these biomarkers provide insight into possible pathophysiologic processes that may contribute to progression of CKD.
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131, USA. vshah@salud.unm.edu
authors.forename: Vallabh O
authors.initials: VO
authors.lastname: Shah
authors.forename: Raymond R
authors.initials: RR
authors.lastname: Townsend
authors.forename: Harold I
authors.initials: HI
authors.lastname: Feldman
authors.forename: Kirk L
authors.initials: KL
authors.lastname: Pappan
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Kensicki
authors.forename: David L
authors.initials: DL
authors.lastname: Vander Jagt
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D002853:Chromatography, Liquid; D003430:Cross-Sectional Studies; D018450:Disease Progression; D008401:Gas Chromatography-Mass Spectrometry; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D055432:Metabolomics / Q000379:methods; D008875:Middle Aged; D011237:Predictive Value of Tests; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000175:diagnosis / Q000503:physiopathology; D012720:Severity of Illness Index; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D015415:Biomarkers