Pathological mechanisms associated with diabetes might cause AD. Mitochondrial dysfunction, oxidative stress and dysregulated calcium homeostasis are all associated with diabetes and might be contributory factors to the development of AD. Glucose auto-oxidation can lead to AGE formation and, as a result, oxidative stress, which is associated with mitochondrial dysfunction. Oxidative stress combined with an increase in intracellular calcium result in a feedforward cycle of continued mitochondrial damage that can cause neuronal death and, hence contribute to AD pathology. Abbreviations: AD, Alzheimer disease; AGE, advanced glycation end product; ROS, reactive oxygen species.