Clinical, biochemical, and immunological characteristics of newly diagnosed nonobese diabetic patients aged 18-45 years in China.

BACKGROUND: The purpose was to characterize the clinical, biochemical, and immunological features of newly diagnosed adult-onset nonobese diabetic patients in China.

METHODS: Newly diagnosed diabetic patients aged 18-45 years with body mass index<23 kg/m(2) were included. Excluding one mitochondrial diabetes patient, there were 102 diabetic patients enrolled in this study. Clinical and biochemical data were collected and analyzed. Radioimmunoassay was used to detect islet autoantibodies.

RESULTS: Among the 102 study participants, 68.6% had type 1 diabetes (T1DM), 20.6% had type 2 diabetes (T2DM), and 10.8% had latent autoimmune diabetes in adults (LADA). About 92% of the T1DM patients presented hyperglycemic symptoms. The corresponding number in T2DM and LADA patients was 13% and 38%, respectively (P<.01). C-peptide in T2DM patients (1.4±0.7 ng/ml) was significantly higher than that in T1DM (0.4±0.3 ng/ml) and LADA (0.4±0.2 ng/ml) patients (P<.01). The prevalence of glutamic acid decarboxylase antibody (GADA) (64.3%) in T1DM patients was higher than that of insulin autoantibody (17.1%) (P<.05). GADA and islet cell antibody (ICA) combination was positive in 75.7% of T1DM patients.

CONCLUSION: T1DM patients accounted for majority of the study sample. In addition, the clinical symptoms of T1DM patients were more severe compared with T2DM patients. GADA is the most sensitive autoantibody marker for adult-onset T1DM and LADA. GADA and ICA are the best test combination for adult-onset autoimmune diabetes. Specific types of diabetes should be in mind when diabetes presents itself with special transmission mode or with other extrapancreatic manifestations.