Latent autoimmune diabetes mellitus in adults (LADA): the role of antibodies to glutamic acid decarboxylase in diagnosis and prediction of insulin dependency

Diabet Med. 1994 Apr;11(3):299-303. doi: 10.1111/j.1464-5491.1994.tb00275.x.


Type 1 diabetes mellitus in adults may present in a manner similar to that of Type 2 diabetes but with a late development of insulin dependency. We studied 65 patients who presented with 'adult-onset' diabetes after the age of 30 years. Of these patients, 19 required insulin therapy. The insulin-treated patients were significantly younger, their onset of diabetes was at an earlier age, and their postprandial serum C-peptide levels were lower than those of the non-insulin-treated group. Moreover, the insulin-treated subjects had a higher mean concentration of antibodies to glutamic acid decarboxylase (GAD) (66.8 +/- 10.2 units) than the patients who did not require insulin (9.9 +/- 1.9 units) (p < 0.001) and their frequency of anti-GAD positivity was 73.7% versus 4.3% (p < 0.001). Thus, among patients attending a diabetes clinic, the majority (73.7%) of subjects who presented with diabetes after 30 years of age and who subsequently required therapy with insulin, actually have the islet cell lesion of Type 1 diabetes which progresses at a slower tempo than in children. We conclude that testing for anti-GAD in adult-onset non-obese diabetic patients should be a routine procedure in order to detect latent insulin-dependency at the earliest possible stage, since this assay can assist in the correct classification of diabetes, and more appropriate therapy.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age of Onset
  • Aged
  • Autoantibodies / blood*
  • Autoimmune Diseases / diagnosis
  • Autoimmune Diseases / immunology*
  • C-Peptide / blood
  • Diabetes Mellitus, Type 1 / diagnosis
  • Diabetes Mellitus, Type 1 / immunology*
  • Diabetes Mellitus, Type 1 / therapy
  • Diabetes Mellitus, Type 2 / diagnosis
  • Diabetes Mellitus, Type 2 / drug therapy
  • Diabetes Mellitus, Type 2 / immunology*
  • Diet, Diabetic
  • Female
  • Glutamate Decarboxylase / immunology*
  • Humans
  • Hypoglycemic Agents / therapeutic use
  • Insulin / therapeutic use*
  • Male
  • Middle Aged
  • Predictive Value of Tests


  • Autoantibodies
  • C-Peptide
  • Hypoglycemic Agents
  • Insulin
  • Glutamate Decarboxylase