title: Antibodies to glutamic acid decarboxylase in young Chinese diabetic patients.
abstract: Antibodies to glutamic acid decarboxylase (GAD) are a useful autoimmune marker for type 1 diabetes mellitus in Caucasians. We examined antibodies to GAD and their relationships with clinical features and pancreatic beta cell function in 140 young Chinese diabetic patients. Over an 18-month period beginning in 1995, 140 young Chinese diabetic subjects with age of onset of disease < or = 35 years and age < 40 years were recruited consecutively, irrespective of their modes of presentation. Clinical features, antibodies to GAD and pancreatic beta cell function (using a glucagon stimulation test) were examined. Increased levels of antibodies to GAD (> 18 units) were detected in 12.1% (n = 17) of these subjects. Forty-three (31%) patients had a classical type 1 presentation and 65 (46%) patients were insulin-deficient based on post-glucagon plasma C-peptide levels. Patients who were insulin-deficient and had a type 1 presentation had the highest prevalence of antibodies to GAD (29.0%) compared with patients who had a type 2 presentation and were non-insulin deficient (6.4%, P = 0.003). Patients who had antibodies to GAD had lower body mass index and waist-hip ratio, earlier onset of disease, lower blood pressure, plasma triglyceride and C-peptide, and higher concentrations of plasma high-density lipoprotein cholesterol and glycated haemoglobin, and were more likely to require drug treatment, compared with those without antibodies to GAD. In conclusion, there was a low prevalence of antibodies to GAD in Chinese young diabetic patients although such antibodies remained a relatively specific marker for insulin deficiency and acute presentation. Causes other than autoimmunity should be sought to explain the high prevalence of insulin deficiency in these young Chinese patients.
authors.affiliation: Department of Medicine and Therapeutics, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin NT, China.
authors.forename: G T
authors.initials: GT
authors.lastname: Ko
authors.forename: J C
authors.initials: JC
authors.lastname: Chan
authors.forename: V T
authors.initials: VT
authors.lastname: Yeung
authors.forename: C C
authors.initials: CC
authors.lastname: Chow
authors.forename: J K
authors.initials: JK
authors.lastname: Li
authors.forename: M S
authors.initials: MS
authors.lastname: Lau
authors.forename: I R
authors.initials: IR
authors.lastname: Mackay
authors.forename: M J
authors.initials: MJ
authors.lastname: Rowley
authors.forename: P
authors.initials: P
authors.lastname: Zimmet
authors.forename: C S
authors.initials: CS
authors.lastname: Cockram
mesh_terms: D000906:Antibodies / Q000097:blood*; D044466:Asian People; D002096:C-Peptide / Q000097:blood; D002681:China / Q000208:ethnology; D003922:Diabetes Mellitus, Type 1 / Q000201:enzymology* / Q000276:immunology / Q000503:physiopathology; D005968:Glutamate Decarboxylase / Q000276:immunology*; D006801:Humans; D007515:Islets of Langerhans / Q000503:physiopathology
chemical_list: D000906:Antibodies; D002096:C-Peptide; D005968:Glutamate Decarboxylase