ABSTRACT
BACKGROUND: It is well known that the clinical characteristics of diabetes mellitus in Korean people are different from those of Western people. The purpose of this study was to investigate the prevalence of the anti-GAD antibody (GADA) in a large number of Korean patients with adult-onset diabetes. METHODS: The GADA was measured by radioimmunoassay for 11,472 adult-onset diabetic patients who visited the Asan Medical Center from 1998 to 2007. According to the fasting C-peptide levels, we classified the patients into an insulin dependent diabetes mellitus group (IDDM; C-peptide or = 1.0 ng/mL). Other clinical and laboratory data were obtained from medical records. RESULTS: Among the 11,147 diabetic patients, 9,250 patients were classified as NIDDM, 922 patients were classified as IDDM and 975 patients excluded. Within the latter group 472 patients were to absolute insulin deficient (C-peptide or = 40 years of age; 3.8%). The GADA-positive NIDDM patients had lower C-peptide and BMI levels, and higher rates of typical diabetic symptoms and insulin treatment. CONCLUSION: The prevalence of GADA in Korean patients with IDDM and NIDDM was lower than that reported in Western populations. It is thus suggested that autoimmunity is a rarer cause of diabetes in Korean people. However, since over 10% of younger-onset NIDDM patients were positive for GADA, routine GADA measurement in such patients is recommended.