Although the exact mechanisms underlying ED in DM are unknown, the fact that DM is characterized by hyperglycaemia and hyperlipidaemia, it is appealing to assume that high glucose and lipid levels have direct adverse effects on endothelial functionality,17, 18, 19 and that reduced NO production along accelerated ET‐1 generation plays a pivotal role in the development of ED. This evidence concerns the gene EDN1 and diabetes mellitus.