RESUMO
BACKGROUND: Von Willebrand factor (vWF) has generally been regarded as a good predictor of vascular risk. However, no previous studies have examined its relationship with coronary calcification. The aim of this study was to determine whether vWF activity is higher in type 1 diabetic patients than controls; its relationship with cardiovascular risk factors; and to endothelial nitric oxide production and coronary artery calcification. MATERIAL/METHODS: Von Willebrand factor activity was measured in 181 type 1 diabetic patients and 188 controls. Coronary artery calcification was measured by Electron Beam Computed Tomography. Forearm blood flow was measured by venous plethysmography in response to intra-brachial infusion of bradykinin, glyceryl trinitrate, noradrenaline and NG-monomethyl-L-arginine (L-NMMA) in 149 subjects. RESULTS: Von Willebrand factor was significantly increased in diabetic patients compared to controls (median 100% vs 87%, p=0.001). Von Willebrand factor activity was significantly higher in diabetic patients with micro/macroalbuminuria than those with normoalbuminuria (109% vs 93%, p<0.001). Among diabetic subjects, being in the top quartile for vWF was associated with a lower response to L-NMMA (p=0.009). There was no association between vWF activity and coronary artery calcification in either the diabetic (p=0.9) or control group (p=0.8). CONCLUSIONS: Cardiovascular risk factors including albuminuria do not explain the high vWF activity in type 1 diabetic patients. There is some evidence that vWF correlates with endothelial nitric oxide production. The lack of correlation with coronary artery calcification indicates that vWF is not a useful marker of atheroma burden.