title: Assessment of insulin resistance by a 13C glucose breath test: a new tool for early diagnosis and follow-up of high-risk patients.
abstract: OBJECTIVE
  Insulin resistance (IR) plays an important role in the pathogenesis of diabetes and non-alcoholic fatty liver disease (NAFLD). Current methods for insulin resistance detection are cumbersome, or not sensitive enough for early detection and follow-up. The BreathID system can continuously analyse breath samples in real-time at the point-of-care. Here we determined the efficacy of the BreathID using the 13C-Glucose breath test (GBT) for evaluation of insulin resistance.
  
  
  METHODS
  Twenty healthy volunteers were orally administered 75 mg of 13C-glucose 1-13C. An oral glucose tolerance test (OGTT) was performed immediately; followed by serum glucose and insulin level determinations using GBT. GBT and OGTT were repeated following exercise, which alters insulin resistance levels.
  
  
  RESULTS
  Within-subject correlations of GBT parameters with serum glucose and serum insulin levels were high. Before and after exercise, between-subjects correlations were high between the relative insulin levels and the % dose recoveries at 90 min (PDR 90), and the cumulative PDRs at 60 min (CPDR 60). Pairwise correlations were identified between pre-exercise Homeostasis Model Assessment (HOMA) IR at 90 min and PDR 90; HOMA B (for beta cell function) 120 and CPDR 30; HOMA IR 60 and peak time post-exercise; and HOMA B 150 with PDR 150.
  
  
  CONCLUSIONS
  The non-invasive real-time BreathID GBT reliably assesses changes in liver glucose metabolism, and the degree of insulin resistance. It may serve as a non-invasive tool for early diagnosis and follow up of patients in high-risk groups.
authors.affiliation: Department of Medicine, Liver Unit, Hebrew University-Hadassah Medical Center Ein Karem, Jerusalem 12000, Israel.
authors.forename: Meir
authors.initials: M
authors.lastname: Mizrahi
authors.forename: Gadi
authors.initials: G
authors.lastname: Lalazar
authors.forename: Tomer
authors.initials: T
authors.lastname: Adar
authors.forename: Itamar
authors.initials: I
authors.lastname: Raz
authors.forename: Yaron
authors.initials: Y
authors.lastname: Ilan
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D001944:Breath Tests / Q000379:methods*; D002247:Carbon Isotopes; D015444:Exercise / Q000502:physiology; D005260:Female; D005947:Glucose / Q000032:analysis* / Q000378:metabolism; D005951:Glucose Tolerance Test; D006706:Homeostasis; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology*; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D008297:Male; D012307:Risk Factors; D012680:Sensitivity and Specificity
chemical_list: D001786:Blood Glucose; D002247:Carbon Isotopes; D007328:Insulin; D005947:Glucose