title: Breath ethanol and acetone as indicators of serum glucose levels: an initial report.
abstract: BACKGROUND
  Many volatile organic compounds are present in exhaled breath and may represent by-products of endogenous biological processes. Ethanol is produced via alcoholic fermentation of glucose by gut bacteria and yeast, while acetone derives from oxidations of free fatty acids, influenced by glucose metabolism. We hypothesized that the integrated analysis of breath ethanol and acetone would provide a good approximation of the blood glucose profile during a glucose load.
  
  
  METHODS
  We collected simultaneous exhaled breath gas, ambient air, and serum glucose and insulin samples from 10 healthy volunteers at baseline and during an oral glucose tolerance test (OGTT) (ingestion of 75 g of glucose followed by 120 min of sampling). Gas samples were analyzed by gas chromatography/mass spectrometry.
  
  
  RESULTS
  Mean glucose values displayed a typical OGTT pattern (rapid increase, peak values at 30-60 min, and gradual return to near baseline by 120 min). Breath ethanol displayed a similar pattern early in the test, with peak values at 30 min; this was followed by a fast return to basal levels by 60 min. Breath acetone decreased progressively below basal levels, with lowest readings obtained at 120 min. A multiple regression analysis of glucose, ethanol, and acetone was used to estimate glucose profiles that correlated with measured glucose values with an average individual correlation coefficient of 0.70, and not lower than 0.41 in any subject.
  
  
  CONCLUSIONS
  The integrated analysis of multiple exhaled gases may serve as a marker of blood glucose levels. Further studies are needed to assess the usefulness of this method in different populations.
authors.affiliation: Center for the Study of Health Effects of Exercise in Children, University of California, Irvine, College of Medicine, Orange, California 92868, USA. pgalasse@uci.edu
authors.forename: Pietro R
authors.initials: PR
authors.lastname: Galassetti
authors.forename: Brian
authors.initials: B
authors.lastname: Novak
authors.forename: Dan
authors.initials: D
authors.lastname: Nemet
authors.forename: Christie
authors.initials: C
authors.lastname: Rose-Gottron
authors.forename: Dan M
authors.initials: DM
authors.lastname: Cooper
authors.forename: Simone
authors.initials: S
authors.lastname: Meinardi
authors.forename: Robert
authors.initials: R
authors.lastname: Newcomb
authors.forename: Frank
authors.initials: F
authors.lastname: Zaldivar
authors.forename: Donald R
authors.initials: DR
authors.lastname: Blake
mesh_terms: D000096:Acetone / Q000032:analysis*; D000328:Adult; D015415:Biomarkers / Q000032:analysis; D001786:Blood Glucose / Q000378:metabolism*; D001944:Breath Tests; D000431:Ethanol / Q000032:analysis*; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D012016:Reference Values; D012044:Regression Analysis
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D000096:Acetone; D000431:Ethanol