The hypothesis of the presented study is: Telmisartan induces an increase of eNOS activity in RBC resulting in an enhanced intravascular NO bioavailability, an ameliorated RBC deformability and a reduction of RBC and platelet aggregation. This could be a potential mechanism of the improvement of microcirculatory disorders, especially in patients with diabetes mellitus and arterial hypertension, treated with Telmisartan.