title: Skin autofluorescence based decision tree in detection of impaired glucose tolerance and diabetes.
abstract: OBJECTIVE
  Diabetes (DM) and impaired glucose tolerance (IGT) detection are conventionally based on glycemic criteria. Skin autofluorescence (SAF) is a noninvasive proxy of tissue accumulation of advanced glycation endproducts (AGE) which are considered to be a carrier of glycometabolic memory. We compared SAF and a SAF-based decision tree (SAF-DM) with fasting plasma glucose (FPG) and HbA1c, and additionally with the Finnish Diabetes Risk Score (FINDRISC) questionnaire±FPG for detection of oral glucose tolerance test (OGTT)- or HbA1c-defined IGT and diabetes in intermediate risk persons.
  
  
  METHODS
  Participants had ≥1 metabolic syndrome criteria. They underwent an OGTT, HbA1c, SAF and FINDRISC, in adition to SAF-DM which includes SAF, age, BMI, and conditional questions on DM family history, antihypertensives, renal or cardiovascular disease events (CVE).
  
  
  RESULTS
  218 persons, age 56 yr, 128M/90F, 97 with previous CVE, participated. With OGTT 28 had DM, 46 IGT, 41 impaired fasting glucose, 103 normal glucose tolerance. SAF alone revealed 23 false positives (FP), 34 false negatives (FN) (sensitivity (S) 68%; specificity (SP) 86%). With SAF-DM, FP were reduced to 18, FN to 16 (5 with DM) (S 82%; SP 89%). HbA1c scored 48 FP, 18 FN (S 80%; SP 75%). Using HbA1c-defined DM-IGT/suspicion ≥6%/42 mmol/mol, SAF-DM scored 33 FP, 24 FN (4 DM) (S76%; SP72%), FPG 29 FP, 41 FN (S71%; SP80%). FINDRISC≥10 points as detection of HbA1c-based diabetes/suspicion scored 79 FP, 23 FN (S 69%; SP 45%).
  
  
  CONCLUSIONS
  SAF-DM is superior to FPG and non-inferior to HbA1c to detect diabetes/IGT in intermediate-risk persons. SAF-DM's value for diabetes/IGT screening is further supported by its established performance in predicting diabetic complications.
authors.affiliation: Department of Medicine, University Medical Center Groningen, and University of Groningen, Groningen, The Netherlands. a.j.smit@umcg.nl
authors.forename: Andries J
authors.initials: AJ
authors.lastname: Smit
authors.forename: Jitske M
authors.initials: JM
authors.lastname: Smit
authors.forename: Gijs J
authors.initials: GJ
authors.lastname: Botterblom
authors.forename: Douwe J
authors.initials: DJ
authors.lastname: Mulder
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D003663:Decision Trees; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000175:diagnosis*; D005215:Fasting; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D012867:Skin / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D011795:Surveys and Questionnaires
chemical_list: D001786:Blood Glucose