Objectives: To investigate the markers of endogenous coagulation/fibrinolysis and vascular endothelial cell function, and to assess the relationships between hemostatic parameters and diabetic vascular complications in type 2 diabetic patients. Materials and Methods: Coagulation and fibrinolysis parameters were measured in 92 type 2 diabetic patients (43 male, 49 female, mean age 50.1 +/- 13.4 years) with (n = 44) and without (n = 48) vascular diabetic complications, and in 40 nondiabetic healthy subjects (20 male, 20 female, mean age 49.8 +/- 15.1 years). Common lipid parameters were also measured. Results: The plasma levels of fibrinogen, antithrombin III (AT III), plasminogen activator inhibitor-1 (PAI-1), von Willebrand factor (vWF) activity and prothrombin time were found to be significantly increased in the type 2 diabetic patients compared with the healthy subjects. Glycosylated hemoglobin lc was inversely correlated with plasma protein S and activated prothrombin time. Protein C and S activities were positively correlated with plasma vWF activity, and were negatively correlated with plasma t-PA levels. vWF activity was negatively correlated with plasma t-PA levels. AT III levels were positively correlated with plasma total cholesterol levels, plasma low density lipoprotein cholesterol levels, plasma triglycerides and D-dimer levels. Plasma PAI-1 levels and factor V activity in diabetic patients with microvascular complications were significantly higher than those of the diabetic patients without microvascular complications. The plasma PAI-1 and platelet count were increased in patients with diabetic retinopathy compared with the diabetic patients without retinopathy. Plasma PAI-1 levels and factor VII activity were significantly higher in the diabetic patients with nephropathy than in diabetic patients without nephropathy. Plasma concentrations of fibrinogen and PAI-1 were significantly higher in the diabetic patients with neuropathy than the diabetic patients without neuropathy. Conclusions: The data demonstrated that patients with type 2 diabetes mellitus had a hypercoagulable state and hypofibrinolysis, thereby indicating that activation of coagulation with a reduced fibrinolytic activity may contribute to the increased risk of vascular disease in type 2 diabetic patients. Copyright (C) 2005 S. Karger AG, Basel.