[Metformin in the treatment of type 1 diabetics--a placebo controlled study]

Metformin is popular for it's complex mechanism of action in treatment of the type 2. diabetes. The effect in type 1. diabetes is studied less frequently. The aim of our open, prospective, placebo controlled study was to assess the effect of metformin in poorly controlled diabetic patients type 1 with high insulin requirements.

In the group comprised of 19 type 1 diabetic patients the insulin resistance was assessed by hyperinsulinemic euglycemic clamp and indirect calorimetry at the beginning of the study (B), 3 months later when metformin in the dose of 2 x 850 mg was added to existing insulin therapy (M) and after 3 months of placebo therapy (P). In the same time-intervals the other parameters were measured. Wilcoxon test was used for statistic analysis. All results are given in arithmetic average +/- SD. Weight (78.6 +/- 17.9; 75.7 +/- 17.8; 76.8 +/- 19.1 kg), Dauly insulin dose (65.4 +/- 15.1; 54.4 +/- 11.2; 54.8 +/- 9.3 IU), HbA1c (8.8 +/- 1.8; 8.2 +/- 1.1; 10.1 +/- 2.8%). Utilisation of glucose (3.5 +/- 1.6; 4.2 +/- 1.7; 4.4 +/- 1.8 mg/kg/min), triglycerides (1.2 +/- 0.5; 1.1 +/- 0.4; 1.3 +/- 0.7 mmol/l), cholesterol (5.1 +/- 0.7; 4.9 +/- 0.7; 5.2 +/- 0.8 mmol/l).

The combination of metformin and the intensive insulin therapy in type 1 diabetic patients led, in contrast to placebo, to the significant reduction in weight (p < 0.001), to the reduction in insulin requirements (p < 0.05), to the improved control of glycaemia (p < 0.01) and to the decrease of FFA during clamp (p < 0.01).