NPPA and Alzheimer disease: The functional mechanism of ANP in AD involves the following: reduced amyloid-β (Aβ) generation and accumulation [12], prevention of pathological and virulent changes caused by central Aβ [13], improvement in insulin resistance in the central nervous system [14], protection against and reduction of nerve cell apoptosis [9, 15–16], improvements in blood-brain barrier function[17], alterations in immuno-inflammatory responses[18], protection of vascular endothelial cells, prevention of vascular atherosclerosis, and regulation of glycolipid metabolism [19–20].