As the incidence rate of insulin-dependent diabetes mellitus (IDDM) is very low in Koreans, there have been little data on the peculiarity of IDDM in Korea. To elucidate the characteristics of IDDM in Korea, we performed HLA serotyping for HLA-A,
-B, -C
and -DR loci, examined islet cell cytoplasmic antibody (ICA) and islet cell surface antibody (ICSA), and analyzed clinical features in 61 patients with young adult-onset IDDM. Twenty hundred and eighty unrelated volunteers were included as
healthy
controls.
The frequency of HLA0DR4 in the patients was higher than that in the controls (57.4% vs 36.4%, relative risk 2.3, corrected p<0.05) and the frequency of HLA-DR2 was lower in the patients as compared with the controls (13.1% vs 32.1%, relative
risk
0.3,
corrected p<0.05). There were no significant differences between the DR4-positive patients and the DR4-negative patients in age at onset, sex ratio, history of diabetic ketoacidosis (DKA), family history of diabetes, current body mass index
(BMI),
levels of basal serum C-peptide and 24-hour urinary C-peptide, and prevalence of ICA and ICSA. Eighteen of 61 patients (29.5%) were positive for ICA and twenty-one (34.4%) were positive for ICSA. There was a negative relationship between the
frequencies
of islet cell autoantibodies and the duration of diabetes. Only 28 of All patients (45.9%) presented with IDDM at the time of diagnosis of diabetes. In contrast, the other patients (54.1%) initially presented with NIDDM and progressed through the
non-insulin-dependent stage of 3.0 years, ranging from 0.7 to 10.0 years, en route to IDDM. However, we did found no differences between the two groups in age at onset, sex ratio, history of DKA, family history of diabetes, current BMI, current
insulin
dose, levels of basal serum C-peptide and 24-hour urinary C-peptide, frequencies of HLA-DR4 and HLA-DR2, and frequencies of islet cell autoantibodies.
We conclude that IDDM that begins in young adulthood is characterized by positive association with HLA-DR4, negative association with HLA-AD2, presence of the islet-specific autoantibodies, and the heterogeneity in the mode of onset and the
earlier
clinical course.
|