title: Incident dysglycemia and progression to type 1 diabetes among participants in the Diabetes Prevention Trial-Type 1.
abstract: OBJECTIVE
  We studied the incidence of dysglycemia and its prediction of the development of type 1 diabetes in islet cell autoantibody (ICA)-positive individuals. In addition, we assessed whether dysglycemia was sustained.
  
  
  METHODS
  Participants (n = 515) in the Diabetes Prevention Trial-Type 1 (DPT-1) with normal glucose tolerance who underwent periodic oral glucose tolerance tests (OGTTs) were followed for incident dysglycemia (impaired fasting glucose, impaired glucose tolerance, and/or high glucose levels at intermediate time points of OGTTs). Incident dysglycemia at the 6-month visit was assessed for type 1 diabetes prediction.
  
  
  RESULTS
  Of 515 participants with a normal baseline OGTT, 310 (60%) had at least one episode of dysglycemia over a maximum follow-up of 7 years. Dysglycemia at the 6-month visit was highly predictive of the development of type 1 diabetes, both in those aged <13 years (P < 0.001) and those aged > or =13 years (P < 0.01). Those aged <13 years with dysglycemia at the 6-month visit had a high cumulative incidence (94% estimate by 5 years). Among those who developed type 1 diabetes after a dysglycemic OGTT and who had at least two OGTTs after the dysglycemic OGTT, 33 of 64 (52%) reverted back to a normal OGTT. However, 26 (79%) of the 33 then had another dysglycemic OGTT before diagnosis.
  
  
  CONCLUSIONS
  ICA-positive individuals with normal glucose tolerance had a high incidence of dysglycemia. Incident dysglycemia in those who are ICA positive is strongly predictive of type 1 diabetes. Children with incident dysglycemia have an especially high risk. Fluctuations in and out of the dysglycemic state are not uncommon before the onset of type 1 diabetes.
authors.affiliation: Division of Endocrinology, University of Miami, Miami, Florida, USA. jsosenko@med.miami.edu
authors.forename: Jay M
authors.initials: JM
authors.lastname: Sosenko
authors.forename: Jerry P
authors.initials: JP
authors.lastname: Palmer
authors.forename: Lisa
authors.initials: L
authors.lastname: Rafkin-Mervis
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Krischer
authors.forename: David
authors.initials: D
authors.lastname: Cuthbertson
authors.forename: Jeffery
authors.initials: J
authors.lastname: Mahon
authors.forename: Carla J
authors.initials: CJ
authors.lastname: Greenbaum
authors.forename: Catherine C
authors.initials: CC
authors.lastname: Cowie
authors.forename: Jay S
authors.initials: JS
authors.lastname: Skyler
mesh_terms: D000293:Adolescent; D001786:Blood Glucose; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000453:epidemiology* / Q000517:prevention & control*; D005260:Female; D018149:Glucose Intolerance / Q000097:blood; D005951:Glucose Tolerance Test; D006801:Humans; D008297:Male; D016016:Proportional Hazards Models
chemical_list: D001786:Blood Glucose