From these work hypothesis, in a previous clinical research we observed that, in healthy, the acute pick of insulin secretion (Stagnaro-Neri and Stagnaro, 1997) activates the microcirculation in all biological systems, while in patients at IRR of AD and, naturally, in patients involved by the disease, even in early stage, microcirculatory activation is totally absent. Here, INS is linked to Alzheimer disease.