Stopping insulin treatment in middle-aged diabetic patients with high postglucagon plasma C-peptide. Effect on glycaemic control, serum lipids and lipoproteins.

We studied the successfulness of stopping insulin treatment in middle-aged diabetic patients aged 45-64 with a high postglucagon C-peptide level and the effects of this change on glycaemic control, serum lipids and lipoproteins. Insulin treatment was successfully stopped in 15 of our 22 patients who satisfied the inclusion criteria for the study and were selected on the basis of a computer file including practically all diabetic patients treated with insulin in the Kuopio University Central Hospital region (population base 250,000 inhabitants). Insulin therapy was restarted in seven patients during the first 3 months after discharge. During the following 9 months insulin therapy was restarted in another three patients so that after a 1-year follow-up period half of the diabetic patients whose insulin therapy was stopped had been switched back to insulin. Insulin therapy was seldom successfully stopped if the postglucagon C-peptide value was under the limit of 1.0 nmol/l. Glycaemic control did not change during the follow-up, although there was a significant weight loss in diabetic patients. No changes were observed in serum lipids or lipoproteins with the exception of LDL cholesterol, which showed a significant reduction during the 3-month follow-up. In conclusion, insulin therapy can often be successfully stopped in patients with postglucagon C-peptide over the limit of 1.0 nmol/l without worsening of glycaemic control and without unfavourable changes in serum lipid and lipoprotein levels.