title: Validation of the BETA-2 Score: An Improved Tool to Estimate Beta Cell Function After Clinical Islet Transplantation Using a Single Fasting Blood Sample.
abstract: The beta score, a composite measure of beta cell function after islet transplantation, has limited sensitivity because of its categorical nature and requires a mixed-meal tolerance test (MMTT). We developed a novel score based on a single fasting blood sample. The BETA-2 score used stepwise forward linear regression incorporating glucose (in millimoles per liter), C-peptide (in nanomoles per liter), hemoglobin A1c (as a percentage) and insulin dose (U/kg per day) as continuous variables from the original beta score data set (n = 183 MMTTs). Primary and secondary analyses assessed the score's ability to detect glucose intolerance (90-min MMTT glucose ≥8 mmol/L) and insulin independence, respectively. A validation cohort of islet transplant recipients (n = 114 MMTTs) examined 12 mo after transplantation was used to compare the score's ability to detect these outcomes. The BETA-2 score was expressed as follows (range 0-42): [Formula: see text] A score <20 and ≥15 detected glucose intolerance and insulin independence, respectively, with >82% sensitivity and specificity. The BETA-2 score demonstrated greater discrimination than the beta score for these outcomes (p < 0.05). Using a fasting blood sample, the BETA-2 score estimates graft function as a continuous variable and shows greater discrimination of glucose intolerance and insulin independence after transplantation versus the beta score, allowing frequent assessments of graft function. Studies examining its utility to track long-term graft function are required.
authors.affiliation: Department of Medicine, Clinical Islet Transplant Program, University of Alberta & Alberta Health Services, Edmonton, Alberta, Canada.|BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.
authors.forename: S
authors.initials: S
authors.lastname: Forbes
authors.affiliation: Department of Medicine, Clinical Islet Transplant Program, University of Alberta & Alberta Health Services, Edmonton, Alberta, Canada.
authors.forename: R A
authors.initials: RA
authors.lastname: Oram
authors.affiliation: Department of Medicine, Clinical Islet Transplant Program, University of Alberta & Alberta Health Services, Edmonton, Alberta, Canada.|Department of Surgery, Clinical Islet Transplant Program, University of Alberta & Alberta Health Services, Edmonton, Alberta, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Smith
authors.affiliation: Department of Medicine, Clinical Islet Transplant Program, University of Alberta & Alberta Health Services, Edmonton, Alberta, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Lam
authors.affiliation: Department of Medicine, Clinical Islet Transplant Program, University of Alberta & Alberta Health Services, Edmonton, Alberta, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Olateju
authors.affiliation: Department of Medicine, Clinical Islet Transplant Program, University of Alberta & Alberta Health Services, Edmonton, Alberta, Canada.|Department of Surgery, Clinical Islet Transplant Program, University of Alberta & Alberta Health Services, Edmonton, Alberta, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Imes
authors.affiliation: Department of Medicine, Clinical Islet Transplant Program, University of Alberta & Alberta Health Services, Edmonton, Alberta, Canada.|Department of Surgery, Clinical Islet Transplant Program, University of Alberta & Alberta Health Services, Edmonton, Alberta, Canada.
authors.forename: A J
authors.initials: AJ
authors.lastname: Malcolm
authors.affiliation: Department of Surgery, Clinical Islet Transplant Program, University of Alberta & Alberta Health Services, Edmonton, Alberta, Canada.
authors.forename: A M J
authors.initials: AM
authors.lastname: Shapiro
authors.affiliation: Department of Medicine, Clinical Islet Transplant Program, University of Alberta & Alberta Health Services, Edmonton, Alberta, Canada.
authors.forename: P A
authors.initials: PA
authors.lastname: Senior
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood*; D001786:Blood Glucose / Q000032:analysis; D002096:C-Peptide / Q000097:blood; D015331:Cohort Studies; D003922:Diabetes Mellitus, Type 1 / Q000601:surgery*; D005215:Fasting / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000032:analysis; D006085:Graft Survival; D006801:Humans; D007515:Islets of Langerhans / Q000502:physiology*; D016381:Islets of Langerhans Transplantation; D008297:Male; D011379:Prognosis; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D002096:C-Peptide; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
keywords: clinical research/practice; diabetes: type 1; endocrinology/diabetology; immunosuppressant; immunosuppressive regimens; islet transplantation; islets of Langerhans; translational research/science