Heterogeneity of early-onset and ketosis-resistant diabetes in Korean subjects - Is it possible to determine cut-off age of early-onset type 2 diabetes?

Objective: To investigate the heterogeneity of early-onset and ketosis-resistant diabetes and to define a not-arbitrary cut-off age for early-onset diabetes based on its clinical and metabolic characteristics, and diabetes complications. Methods: We classified 1015 early-onset diabetes subjects aged 21-40 into four groups (group I, age at diagnosis 21-25 years; group II, 26-30; group III, 31-35; group IV, 36-40). Familial and diabetic history, statue of insulin secretion, metabolic parameters, and diabetes complications were analyzed. Results: No significant difference in family history or the rate of diabetic complication was found in the four groups. Subjects with a 21 to a 25-year-old diabetes onset had the lowest serum C-peptide levels, with 50% of the cumulative 24-h urine C-peptide levels of the other three groups (p < 0.0001). This group also had the lowest prevalence of hyperlipidemia and arterial hypertension (p < 0.01 and <0.0001, respectively). Group III was found to have a higher prevalence of insulin insufficiency and hypertension than group IV. Conclusion: Our data based on insulin secretory function and metabolic factors might suggest that a cut-off age of 26 years might be warranted in Korean patients. Korean early-onset type 2 diabetes patients tend to be non-obese and insulin secretory dysfunction.