Glutamic acid decarboxylase antibodies in non-insulin-dependent diabetes patients with secondary sulfonylurea failure in Thailand.
The objective of this study was to determine the frequency of glutamic acid decarboxylase antibody (GAD-Ab) in Thai non-insulin-dependent diabetes (NIDDM) patients who had secondary sulfonylurea failure. Sera were collected from 40 NIDDM patients, who had history of secondary failure to treatment with sulfonylurea, for analysis of fasting c-peptide and GAD-Ab. Both c-peptide and GAD-Ab were measured using radioimmunoassay method. Of 40 patients, ten (25.0%) were positive for GAD-Ab with a mean level of 59.9 U/ml (median 58.5, range 3.4-127). Patients with (GAD-Ab (+) had a significantly lower fasting c-peptide levels than those with GAD-Ab(-) albeit shorter duration of diabetes (0.21 +/- 0.19 (S.D.) versus 0.52 +/- 0.33 nmol/l; P = 0.003). Duration of treatment with sulfonylurea in patients with GAD-Ab (+) was also shorter (4.6 +/- 3.5 versus 10.4 +/- 5.5 years; P = 0.001). Age at onset of diabetes did not differ between these two groups. Among 40% of patients who had insulin deficiency (fasting c-peptide level < 0.33 nmol/1), GAD-Ab was present in half and these GAD-Ab(+) patients had significantly shorter duration of sulfonylurea treatment (3.3 +/- 2.3 versus 10.0 +/- 7.9 years; P = 0.018). In conclusion, the frequency of GAD-Ab in Thai NIDDM patients with secondary sulfonylurea failure in this study was 25%. Almost all GAD-Ab(+) patients had insulin deficiency and most had been initially treated with sulfonylurea for a few years before depending on insulin. This group of patients represents a slowly progressive type I or latent autoimmune diabetes in adult diabetic population.
Rattarasarn
C
C
Department of Medicine, Faculty of Medicine, Prince of Songkla University, Thailand.
Aguilar Diosdado
M
M
Soonthornpun
S
S
D000328:Adult; D000368:Aged; D000906:Antibodies / Q000097:blood*; D002096:C-Peptide / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D005260:Female; D005968:Glutamate Decarboxylase / Q000097:blood / Q000276:immunology*; D006801:Humans; D007004:Hypoglycemic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D013453:Sulfonylurea Compounds / Q000009:adverse effects / Q000627:therapeutic use*; D013785:Thailand; D017211:Treatment Failure
D000906:Antibodies; D002096:C-Peptide; D007004:Hypoglycemic Agents; D013453:Sulfonylurea Compounds; D005968:Glutamate Decarboxylase