title: (1)H nuclear magnetic resonance metabolomics analysis identifies novel urinary biomarkers for lung function.
abstract: Chronic obstructive pulmonary disease (COPD), characterized by chronic airflow limitation, is a serious public health concern. In this study, we used proton nuclear magnetic resonance ((1)H NMR) spectroscopy to identify and quantify metabolites associated with lung function in COPD. Plasma and urine were collected from 197 adults with COPD and from 195 without COPD. Samples were assayed using a 600 MHz NMR spectrometer, and the resulting spectra were analyzed against quantitative spirometric measures of lung function. After correcting for false discoveries and adjusting for covariates (sex, age, smoking) several spectral regions in urine were found to be significantly associated with baseline lung function. These regions correspond to the metabolites trigonelline, hippurate and formate. Concentrations of each metabolite, standardized to urinary creatinine, were associated with baseline lung function (minimum p-value = 0.0002 for trigonelline). No significant associations were found with plasma metabolites. Urinary hippurate and formate are often related to gut microflora. This could suggest that the microbiome varies between individuals with different lung function. Alternatively, the associated metabolites may reflect lifestyle differences affecting overall health. Our results will require replication and validation, but demonstrate the utility of NMR metabolomics as a screening tool for identifying novel biomarkers of pulmonary outcomes.
authors.affiliation: Center for Biomarker Research and Personalized Medicine, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, USA. jlmcclay@vcu.edu
authors.forename: Joseph L
authors.initials: JL
authors.lastname: McClay
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Adkins
authors.forename: Nancy G
authors.initials: NG
authors.lastname: Isern
authors.forename: Thomas M
authors.initials: TM
authors.lastname: O'Connell
authors.forename: Jan B
authors.initials: JB
authors.lastname: Wooten
authors.forename: Barbara K
authors.initials: BK
authors.lastname: Zedler
authors.forename: Madhukar S
authors.initials: MS
authors.lastname: Dasika
authors.forename: Bradley Todd
authors.initials: BT
authors.lastname: Webb
authors.forename: Bobbie-Jo
authors.initials: BJ
authors.lastname: Webb-Robertson
authors.forename: Joel G
authors.initials: JG
authors.lastname: Pounds
authors.forename: Edward L
authors.initials: EL
authors.lastname: Murrelle
authors.forename: Mark F
authors.initials: MF
authors.lastname: Leppert
authors.forename: Edwin J C G
authors.initials: EJ
authors.lastname: van den Oord
mesh_terms: D000328:Adult; D000470:Alkaloids / Q000652:urine; D015415:Biomarkers / Q000652:urine; D002986:Clinical Trials as Topic; D005260:Female; D005561:Formates / Q000652:urine; D006626:Hippurates / Q000652:urine; D006801:Humans; D016018:Least-Squares Analysis; D008168:Lung / Q000502:physiology* / Q000503:physiopathology; D008297:Male; D055432:Metabolomics / Q000379:methods*; D008875:Middle Aged; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D029424:Pulmonary Disease, Chronic Obstructive / Q000652:urine*; D012129:Respiratory Function Tests / Q000379:methods*
chemical_list: D000470:Alkaloids; D015415:Biomarkers; D005561:Formates; D006626:Hippurates; C030544:formic acid; C009560:trigonelline; C030514:hippuric acid