Increased vascular resistance in vasodilated skin an indicator of diabetic microangiopathy?

The method of isotope clearance has been used to investigate the vascular resistance in skin in severely atherosclerotic patients with and without diabetes. Dilatation of the skin vessels was achieved by the injection of histamine with a radioactive tracer (99mTc). The perfusion pressure of the skin was varied by applying graded external counter pressure over the injected area. The blood flow at any given perfusion pressure was lower (and thus the resistance higher) in the diabetic subjects (P = 0.01). These results could be explained if there was microangiopathy affecting the skin vessels.