PNNL

Abstract

Objective: There is an estimated 3.7 million people with undiagnosed type 1 diabetes (T1D), living primarily in poor areas of the globe. Therefore, there is a need for non-invasive, affordable tests to provide accurate diagnosis despite the time post-disease onset and fasting state. Here, we studied persistent urinary T1D biomarkers that can be used to develop such tests. Material and Methods: We analyzed the urine metabolomes of three independent cohorts of samples collected within 48 h (from Indiana University), and 1 year (from University of Colorado) and 1-10 years (6 years in average) (from Children’s National Medical Center) post-diagnosis. Samples were submitted to gas chromatography-mass spectrometry and machine learning analyses to determine diagnostic metabolite panels. The data were also mapped into a metabolic pathway to understand persistently regulated processes in T1D. Results: Seven metabolites showed consistent increases in all three cohorts: D-glucose, D-mannose, myo-inositol, 3-hydroxyisobutyric acid, gluconolactone, D-gluconic acid, and D-glucuronic acid. A combination of machine learning analysis and metabolite ratios as biomarker candidates diagnosed T1D with high sensitivity and specificity across different cohorts and times. Mapping the regulated metabolites into a pathway showed impairment in glycolysis and overflow of glucose towards other pathways in subjects with T1D that was persistent over time. Conclusions: We identified and cross-validated highly specific and sensitive urinary biomarkers. This opens opportunities to develop affordable, robust, and non-invasive tests. The results also show that most of the biomarkers were signatures of dysregulated glucose metabolism. Abbreviations: AUC, area under a receiver operating characteristic curve; BDCD, Barbara Davis Center for Diabetes; CNMC; Children’s National Medical Center; GC-MS, gas chromatography-mass spectrometry; GLMM, generalized linear mixed effects model; IUSOM, Indiana University School of Medicine; JCVI, J Craig Venter Institute; T1D, type 1 diabetes