Although the HLA class II alleles and immunological abnormalities are associated with type 1 diabetes mellitus (T1DM) in all racial groups, there are considerable variations in the genotypes and the prevalence of autoantibodies. In order to investigate the characteristics of the immunogenetic patterns and to use these as an early diagnostic tool and guideline for a therapeutic plan, we examined the clinical characteristics and the patterns of anti-GAD antibody (GADA), IA-2 antibody (IA-2A), HLA-DR and HLA-DQ in Korean adult-onset T1DM patients. Adult-onset patients had higher serum C-peptide levels than child-onset patients. In adult-onset patients, the prevalence of GADA and IA-2A were 59.5% and 15.3% respectively, and increased frequencies of HLADR4 and-DR9 were found. The frequencies of HLADQA1,-DQB1 and-DQ heterodimers were similar to those of the control, but child-onset patients had high frequencies of the HLA-DR3,-DR4,-DR9, DQA1*0301, DQA1*0501 and DQB1*0201 genotypes. In conclusion, Korean adult-onset T1DM patients had a lower prevalence of GADA, which was comparable to that found in Caucasian patients. The detection of GADA might help to predict the insulin dependency of adult-onset diabetes. Difference in the frequencies of diabetes associated with HLA type suggests that there might be a heterogeneity in the pathogenesis of diabetes according to the age of onset.

Background: Atherosclerosis is one of the major causes of morbidity and mortality in patients with type 2 diabetes and pioglitazone has been reported to have antiatherogenic effect.The aim of this study was to investigate whether pioglitazone affects carotid intima-media thickness (IMT) and pulsatility index (PI) in type 2 diabetic patients.Methods: A total of 40 type 2 diabetic patients were included and divided into two groups: the pioglitazone-treated group (pioglitazone 15 mg/day with gliclazide 80～320 mg/day for 12 weeks) (n = 20) and control group (gliclazide 80～320 mg/day for 12 weeks) (n = 20).The changes in lipid profile, insulin resistance, IMT, and PI were monitored to determine that pioglitazone improves cerebrovascular blood flow.Results: The pioglitazone treatment significantly increased HDL-C, reduced triglyceride, insulin resistance and PI.IMT tended to decrease but the change was not significant.This study revealed that treatment with pioglitazone was associated with the improvement of cerebrovascular blood flow.Conclusions: Pioglitazone appears to be effective for the improvement of cerebrovascular blood flow in type 2 diabetic patients (J Kor Diabetes Assoc 30:96～103, 2006).