VWF and diabetes mellitus: Finally, the multivariate model for the whole study population showed that vWF, PAI-1, fibrinogen and diabetes mellitus were the independent predictors of t50% (R2 = 0.58, p < 0.001; Table 3) whereas vWF was the only independent predictor of Ks (R2 = 0.22, p < 0.001; Table 3).