Abstract
In order to clarify the time-course of insulin dependence and to evaluate the diagnostic criteria for insulin-dependent diabetes mellitus, changes of insulin dependence were followed up in non-obese patients with diabetes diagnosed under the age of 30 years. The basal C-peptide (B-CPR; ng/ml) and the insulin dose (I-dose; U/kg) were followed up at 1 month, 6 months, 1 year, 2 years, and 3 years after diagnosis, and each patient was classified at each observation as follows: Class A, B-CPR≤0.6 and I-dose≥0.5; Class B, B-CPR≤0.6 and I-dose<0.5; Class C, B-CPR>0.6 and 1 dose<0.5; Class D, B-CPR>0.6 and I-dose≥0.5. All the patients who were in Classes A and B at 1 month were classified as Class A at 3 years. Of the patients who were in Classes C and D at 1 month, 19% and 50%, respectively were classified as Class A at 3 years. The slow progression towards insulin dependence was observed more in males and in patients with positive ketonuria at the onset. We conclude that patients with a low B-CPR at 1 month will progress toward insulin dependence within 3 years.
