title: Differences in exhaled gas profiles between patients with type 2 diabetes and healthy controls.
abstract: OBJECTIVE
  Recent advances in analytical technology allow the detection of several hundred volatile organic compounds (VOCs) in human exhaled air, many of which reflect unidentified endogenous pathways. This study was performed to determine whether a breath gas analysis using proton transfer reaction-mass spectrometry (PTR-MS) could serve as a noninvasive method to distinguish between patients with type 2 diabetes mellitus and healthy controls.
  
  
  METHODS
  Breath and room air samples were measured from 21 patients with insulin-treated type 2 diabetes and 26 healthy controls. VOCs in the mass range of 20-200 atomic mass units were analyzed using PTR-MS.
  
  
  RESULTS
  We identified eight masses characteristic of endogenous VOCs that showed significant differences in the gas profiles of patients with type 2 diabetes and healthy control subjects. Using these VOCs for linear discriminant analysis, the sensitivity and specificity were found to be 90% and 92%, respectively.
  
  
  CONCLUSIONS
  These results suggest that it is possible to separate patients with diabetes mellitus type 2 from healthy controls by multivariate analysis of exhaled endogenous VOCs. This is a first step towards the development of a noninvasive test using breath gas of at-risk persons and making it an attractive option for large-scale testing of at-risk populations. However, the establishment of exhaled volatiles as metabolic markers requires additional confirmatory investigations.
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany.
authors.forename: M B
authors.initials: MB
authors.lastname: Greiter
authors.forename: L
authors.initials: L
authors.lastname: Keck
authors.forename: T
authors.initials: T
authors.lastname: Siegmund
authors.forename: C
authors.initials: C
authors.lastname: Hoeschen
authors.forename: U
authors.initials: U
authors.lastname: Oeh
authors.forename: H G
authors.initials: HG
authors.lastname: Paretzke
mesh_terms: D000328:Adult; D001944:Breath Tests / Q000379:methods*; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis* / Q000503:physiopathology; D045853:Exhalation; D005260:Female; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000379:methods; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric