title: Clinical and Laboratory Evaluation of a New Specific Point-of-Care Test for Intact Proinsulin.
abstract: Intact proinsulin is a biomarker for pancreatic ß-cell dysfunction. In large prospective studies in nondiabetic subjects, elevated intact proinsulin predicted development of type 2 diabetes and/or macrovascular events up to 7 years in advance. This study was performed to evaluate a new semiquantitative lateral flow-based point-of-care rapid test (POCT) for elevated intact proinsulin (cutoff: 15 pmol/L). The test requires 10 µL of capillary whole blood, with visual readout after 5 minutes. It is best applied at 2 hours after a glucose challenge or a meal.
  
  
  
  POCT results were obtained by health care professionals from 60 patients and healthy subject (33 female, 27 male, 28 type 2 diabetes, age: 53.6 ± 12.3 years). An additional venous blood sample was obtained from all participants for measurement of intact proinsulin by means of a quantitative ELISA reference method (TecoMedical, Sissach, Switzerland).
  
  
  
  Elevated intact proinsulin levels (>15 pmol/L) were determined by the reference method in 26 participants, of whom 22 were also positive with the POCT (sensitivity: 85%). All 34 subjects with low intact proinsulin levels were tested negative by the POCT (specificity: 100%).
  
  
  
  The test successfully detected elevated postprandial intact proinsulin levels in 85% of the tested subjects and no false positive test result occurred. This POCT can therefore serve as a simple screening tool for identification of patients with prevalent ß-cell dysfunction, who are at high risk for development of type 2 diabetes and/or macrovascular events within the next 5-7 years.
authors: 1 Pfützner Science & Health Institute, Mainz, Germany.|2 University of Applied Science, Bingen, Germany.|3 Sciema UG, Mainz, Germany.|4 Insulin NG LLC, Naples, FL, USA.
authors: Andreas
authors: A
authors: Pfützner
authors: 3 Sciema UG, Mainz, Germany.
authors: Anke H
authors: AH
authors: Pfützner
authors: 5 University Hospital Marburg, Department of Endocrinology and Diabetes, Marburg, Germany.
authors: Peter H
authors: PH
authors: Kann
authors: 4 Insulin NG LLC, Naples, FL, USA.
authors: Gunther
authors: G
authors: Burgard
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000175:diagnosis*; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D007118:Immunoassay; D008297:Male; D008875:Middle Aged; D000067716:Point-of-Care Testing; D011384:Proinsulin / Q000097:blood*; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D011384:Proinsulin
keywords: diabetes prediction; intact proinsulin; point-of-care test; ß-cell dysfunction