Latent autoimmune diabetes mellitus in adults (LADA): the role of antibodies to glutamic acid decarboxylase in diagnosis and prediction of insulin dependency.
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.
Zimmet
P Z
PZ
International Diabetes Institute, University Melbourne, Australia.
Tuomi
T
T
Mackay
I R
IR
Rowley
M J
MJ
Knowles
W
W
Cohen
M
M
Lang
D A
DA
D000328:Adult; D017668:Age of Onset; D000368:Aged; D001323:Autoantibodies / Q000097:blood*; D001327:Autoimmune Diseases / Q000175:diagnosis / Q000276:immunology*; D002096:C-Peptide / Q000097:blood; D003922:Diabetes Mellitus, Type 1 / Q000175:diagnosis / Q000276:immunology* / Q000628:therapy; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology*; D003927:Diet, Diabetic; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology*; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D007328:Insulin / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests
D001323:Autoantibodies; D002096:C-Peptide; D007004:Hypoglycemic Agents; D007328:Insulin; D005968:Glutamate Decarboxylase