Effect of metformin on fibrinolytic parameters in insulin-treated, type 2 diabetic patients

In the present study, we measured fibrinolytic parameters, including PAI-1 antigen and activity in a group of type 2 diabetic patients in secondary oral anti-diabetic failure treated with insulin alone or with insulin plus metformin.

12 type 2 diabetic patients in secondary oral anti-diabetic failure were randomly allocated into two groups receiving insulin alone or insulin plus metformin 1000 mg twice a day; six weeks later, the treatments were swapped over. At the end of each treatment period, blood samples were withdrawn for metabolic and fibrinolytic analysis.

There were no significant differences in fasting blood glucose, fructosamine or fibrinogen; LDL cholesterol, PAI-1 antigen and activity, insulin needs were reduced by the inulin plus metformin regimen (LDL cholesterol: 1.59 +/- 0.62 versus 1.28 +/- 0.5 mmol/l, PAI-1 antigen: 28.3 +/- 17.4 versus 23.9 +/- 18 ng/ml, PAI-1 activity: 23.8 +/- 9.6 versus 21.9 +/- 10 IU/ml, insulin needs: 64 +/- 18 versus 52 +/- 15 U/day (p<0.05).

In type 2 diabetic patients with secondary oral treatment failure, insulin alone controlled blood glucose but had no effect on the levels of PAI-1; addition of metformin improved the fibrinolytic parameters.