| Title: | Indole as a new tentative marker in exhaled breath for non-invasive blood glucose monitoring of diabetic subjects |
| Author(s): | Fink H; Maihofer T; Bender J; Schulat J; |
| Address: | "Roche Diabetes Care GmbH, Chemical and Instrumental Analytics, Sandhofer Str 116 Mannheim, Germany, 68305. Roche Diabetes Care Incorporated, Chemical & Instrumental Analytics, 9115 Hague Rd, PO Box 50547, Indianapolis, IN, United States of America. Roche Diabetes Care GmbH, Chemical Disposable and Detection, Sandhofer Str 116 Mannheim, Germany, 68305" |
| ISSN/ISBN: | 1752-7163 (Electronic) 1752-7155 (Linking) |
| Abstract: | "Blood glucose monitoring (BGM) is the most important part of diabetes management. In classical BGM, glucose measurement by test strips involves invasive finger pricking. We present results of a clinical study that focused on a non-invasive approach based on volatile organic compounds (VOCs) in exhaled breath. Main objective was the discovery of markers for prediction of blood glucose levels (BGLs) in diabetic patients. Exhaled breath was measured repeatedly in 60 diabetic patients (30 type 1, 30 type 2) in fasting state and after a standardized meal. Proton transfer reaction time of flight mass spectrometry was used to sample breath every 15 min for a total of 6 h. BGLs were tested in parallel via BGM test strips. VOC signals were plotted against glucose trends for each subject to identify correlations. Exhaled indole (a bacterial metabolite of tryptophan) showed significant mean correlation to BGL (with negative trend) and significant individual correlation in 36 patients. The type of diabetes did not affect this result. Additional experiments of one healthy male subject by ingestion of lactulose and(13)C-labeled glucose (n= 3) revealed that exhaled indole does not directly originate from food digestion by intestinal microbiota. As indole has been linked to human glucose metabolism, it might be a tentative marker in breath for non-invasive BGM. Clinical studies with greater diversity are required for confirmation of such results and further investigation of metabolic pathways" |
| Keywords: | Blood Glucose Blood Glucose Self-Monitoring Breath Tests/methods *Diabetes Mellitus Exhalation Humans Indoles Male *Volatile Organic Compounds/analysis breath diabetes glucose monitoring indole non-invasive proton transfer time of flight mass spectrometry; |
| Notes: | "MedlineFink, Herbert Maihofer, Tim Bender, Jeffrey Schulat, Jochen eng Research Support, Non-U.S. Gov't England 2021/12/24 J Breath Res. 2022 Jan 7; 16(2). doi: 10.1088/1752-7163/ac4610" |
