title: Novel noninvasive breath test method for screening individuals at risk for diabetes.
abstract: OBJECTIVE
  Diagnosis of pre-diabetes and early-stage diabetes occurs primarily by means of an oral glucose tolerance test (OGTT), which requires invasive blood sampling. The aim of this study was to determine whether differences exist in breath (13)CO(2) excretion during a (13)C-labeled OGTT between individuals with normal glucose tolerance (NGT) and individuals with pre-diabetes and early-stage diabetes (PDED) and whether these differences correlated with blood glucose kinetics.
  
  
  METHODS
  Blood and breath samples were collected at baseline and every 30 min for a 10-h period after ingestion of 75 g glucose isotopically labeled with 150 mg [U-(13)C(6)]D-glucose.
  
  
  RESULTS
  Age (56 +/- 5 vs. 47 +/- 3 years) and BMI (31 +/- 2 vs. 31 +/- 2 kg/m(2)) were not different between individuals with NGT (n = 10) and PDED (n = 7), respectively. Blood glucose concentrations were significantly higher in those with PDED compared with those with NGT from baseline to 4.5 h after glucose ingestion (P <or= 0.05). Glucose-derived breath (13)CO(2) was significantly lower in individuals with PDED compared with those with NGT from 1 to 3.5 h after glucose (P <or= 0.05). Peak breath (13)CO(2) abundance occurred at 4.5 and 3.5 h in individuals with PDED and NGT, respectively (36.87 +/- 3.15 vs. 41.36 +/- 1.56 per thousand delta over baseline).
  
  
  CONCLUSIONS
  These results suggest that this novel breath test method may assist in recognition of pre-diabetes or early-stage diabetes in at-risk persons without the need for invasive blood sampling, thus making it an attractive option for large-scale testing of at-risk populations, such as children.
authors.affiliation: Department of Internal Medicine, The University of Texas Medical Branch, Galveston, Texas, USA.
authors.forename: E Lichar
authors.initials: EL
authors.lastname: Dillon
authors.forename: Morteza
authors.initials: M
authors.lastname: Janghorbani
authors.forename: James A
authors.initials: JA
authors.lastname: Angel
authors.forename: Shanon L
authors.initials: SL
authors.lastname: Casperson
authors.forename: James J
authors.initials: JJ
authors.lastname: Grady
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Urban
authors.forename: Elena
authors.initials: E
authors.lastname: Volpi
authors.forename: Melinda
authors.initials: M
authors.lastname: Sheffield-Moore
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D002245:Carbon Dioxide / Q000032:analysis; D003920:Diabetes Mellitus / Q000097:blood / Q000175:diagnosis*; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity
chemical_list: D001786:Blood Glucose; D007328:Insulin; D002245:Carbon Dioxide