Tables 1 and 2 show thatsmoking is positively associated with the incidence of T2DM. Studies have shown thatpeople who smoke have twice the risk of impaired insulin secretion than people whonever smoke (33).Nicotine has been linked to an increased risk of T2DM from smoking. Nicotine affectsinsulin secretion through nicotinic acetylcholine receptors on islet beta cells andmediates nicotine to increase the apoptosis of islet beta cells through themitochondrial receptor pathway (34). This evidence concerns the gene INS and type 2 diabetes mellitus.