In a prospective study of newly detected diabetic patients in 1989-1991 the authors focused their attention on the evaluation of blood sugar levels and HbA1c during manifestation of DM and the amount of insulin secretion in relation to diabetes type 1 and 2 in adult patients. Part 1 of the paper reveals great differences in the fasting blood sugar level during manifestation of DM (26% of the group had a blood sugar level lower than 8.5 mmol/l and 14% above 15 mmol/l) even after 1-4 months treatment (3.8-17.2 mmol/l). Similar differences were found in HbA1c values (4.5-12.9%). High C-peptide levels revealed an incorrectly assessed diagnosis of type 1 diabetes in 16.7% diabetics and low C-peptide values on fasting and postporandial values were at variance with the diagnosis of type 2 diabetes in 6% of the group.

        Key words: DM type 1 - DM type 2 -C-peptide