Effect of metformin on fibrinolytic parameters in insulin-treated, type 2 diabetic patients.
OBJECTIVE: 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. RESEARCH DESIGN AND METHODS: 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 At the end of each treatment period, blood samples were withdrawn for metabolic and fibrinolytic analysis. RESULTS: 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). CONCLUSION: 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.