This book consists of fundamentals of Vascular Endothelium Dysfunction and role of insulin in prevention of vascular dysfunction either by increased homocysteine levels or high cholesterol level.It includes methods for inducing vascular dysfunction and protective role played by insulin via molecular basis of PI3K/AkT pathway.The organization of book is simple and text is divided into different contents.The results are discussed in the forms of graphs, tables and pictures. Endothelium dysfunction is mostly associated cardiovascular disorder, dementia, cerebrovascular diosoders.