The presence of GAD and IA-2 antibodies in youth with a type 2 diabetes phenotype: results from the TODAY study

Diabetes Care. 2010 Sep;33(9):1970-5. doi: 10.2337/dc10-0373. Epub 2010 Jun 2.


Objective: To determine the frequency of islet cell autoimmunity in youth clinically diagnosed with type 2 diabetes and describe associated clinical and laboratory findings.

Research design and methods: Children (10-17 years) diagnosed with type 2 diabetes were screened for participation in the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study. Measurements included GAD-65 and insulinoma-associated protein 2 autoantibodies using the new National Institute of Diabetes and Digestive and Kidney Diseases/National Institutes of Health (NIDDK/NIH) standardized assays, a physical examination, and fasting lipid, C-peptide, and A1C determinations.

Results: Of the 1,206 subjects screened and considered clinically to have type 2 diabetes, 118 (9.8%) were antibody positive; of these, 71 (5.9%) were positive for a single antibody, and 47 were positive (3.9%) for both antibodies. Diabetes autoantibody (DAA) positivity was significantly associated with race (P < 0.0001), with positive subjects more likely to be white (40.7 vs. 19%) (P < 0.0001) and male (51.7 vs. 35.7%) (P = 0.0007). BMI, BMI z score, C-peptide, A1C, triglycerides, HDL cholesterol, and blood pressure were significantly different by antibody status. The antibody-positive subjects were less likely to display characteristics clinically associated with type 2 diabetes and a metabolic syndrome phenotype, although the range for BMI z score, blood pressure, fasting C-peptide, and serum lipids overlapped between antibody-positive and antibody-negative subjects.

Conclusions: Obese youth with a clinical diagnosis of type 2 diabetes may have evidence of islet autoimmunity contributing to insulin deficiency. As a group, patients with DAA have clinical characteristics significantly different from those without DAA. However, without islet autoantibody analysis, these characteristics cannot reliably distinguish between obese young individuals with type 2 diabetes and those with autoimmune diabetes.

Trial registration: NCT00081328.

Publication types

  • Clinical Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Autoantibodies / metabolism*
  • C-Peptide / metabolism
  • Child
  • Diabetes Mellitus, Type 2 / immunology*
  • Diabetes Mellitus, Type 2 / metabolism*
  • Female
  • Glutamate Decarboxylase / immunology*
  • Humans
  • Islets of Langerhans / metabolism
  • Male


  • Autoantibodies
  • C-Peptide
  • ICA512 autoantibody
  • Glutamate Decarboxylase

Associated data