Clinical characteristics of patients with the initial diagnosis of NIDDM with positivity for antibodies to glutamic acid decarboxylase

Exp Clin Endocrinol Diabetes. 1997;105(6):327-30. doi: 10.1055/s-0029-1211773.


The measurement of islet cell antibodies (ICA) and antibodies to glutamic acid decarboxylase (GAD-Ab) is clinically useful in evaluating patients with insulin-dependent diabetes mellitus (IDDM). Our objective was to correlate the clinical characteristics of patients with non-insulin-dependent diabetes mellitus (NIDDM) who exhibited positivity for GAD-Ab vs. patients who were negative for this enzyme. The serum level of GAD-Ab was measured by radiobinding assay (RBA) using pig brain GAD. The prevalence of GAD-Ab in the 181 patients was low; the 8 involved subjects (4.4%) were all females. The NIDDM patients who were GAD-Ab-positive were significantly younger, experienced diabetes onset at an early age, had a shorter duration of diabetes, a shorter interval between diabetes onset to initiation of insulin therapy, a lower body mass index (BMI), a lower serum C-peptide value, and required a higher dose of insulin. A higher proportion of the GAD-Ab-positive patients was receiving insulin therapy.

Conclusions: Clinical characteristics of patients with NIDDM who were positive for GAD-Ab differed significantly from those of the patients negative for GAD-Ab. The profile of the GAD-Ab-positive patients with NIDDM resembled that of those with IDDM.

MeSH terms

  • Adult
  • Autoantibodies / blood*
  • Body Mass Index
  • C-Peptide / blood
  • Diabetes Mellitus, Type 2 / drug therapy
  • Diabetes Mellitus, Type 2 / immunology*
  • Diabetes Mellitus, Type 2 / physiopathology
  • Female
  • Glutamate Decarboxylase / immunology*
  • Humans
  • Insulin / administration & dosage
  • Insulin / therapeutic use
  • Islets of Langerhans / immunology
  • Male
  • Middle Aged


  • Autoantibodies
  • C-Peptide
  • Insulin
  • Glutamate Decarboxylase