Lack of effect of glibenclamide on insulin requirements and diabetic control in persons with insulin-dependent diabetes

Abstract

The addition of the sulphonylurea agent, glibenclamide, to the insulin therapy of six patients with insulin-dependent diabetes mellitus was studied in a double-blind cross-over trial. The subjects produced no measurable plasma C-peptide after stimulation with glucagon, weighed within 10% of their ideal body weight and required approximately 1 U/kg per day of insulin. After one month of close supervision while the patients were being managed with diet and insulin therapy alone, glibenclamide, three times a day, or a placebo, was added to the therapy for one month. After a further one-month control period, the alternate agent was administered for one month. No change in the insulin requirement or the glycosylated haemoglobin levels, or in the 24-hour profiles of the plasma glucose and free insulin levels in response to a standard diet, was observed at the end of each treatment period. This study suggests that any enhancement of insulin sensitivity by sulphonylurea treatment in persons with insulin-dependent diabetes mellitus is only minor and clinically-unimportant.