INS and Alzheimer disease: Potential underlying mechanisms associating type 2 diabetes with AD include the disruptive effect of excess insulin on synaptic plasticity (Biessels & Kappelle, 2005), mitochondrial dysfunction (common to both type 2 diabetes and AD) (Correia et al., 2012), glucose hypometabolism (Li, Risacher et al., 2016) and hypoperfusion (Dake et al., 2020).