MAPT and Alzheimer disease: Insulin resistance in T2DM disrupts many metabolic pathways, including glucose metabolism, synaptic maintenance, vascular function, tau phosphorylation, and β-amyloid regulation that support healthy cognitive functioning (Biessels et al., 1998; Gasparini et al., 2001; Schubert et al., 2004) and recent longitudinal studies have shown there is an associated increased risk of developing Alzheimer disease (AD) (Schrijvers et al., 2010; van Himbergen et al., 2012).