Insulin and the future treatment of Alzheimer’s disease

Alzheimer’s disease is a neurodegenerative disorder leading to dementia. Scientific efforts in the last decade focused mainly on understanding pathophysiology of disease and possible pharmacological approach to alleviate cognitive decline symptoms. Amyloid cascade hypothesis though criticized, remains the leading hypothesis to understand pathogenic mechanisms of cognitive decline. Intriguingly, changes of metabolic activity of cortical neurons are associated with reduced or absent sensitivity to insulin in Alzheimer’s disease brain. Insulin is a multipotent hormone regulating, not only glucose levels, but also cell survival and synaptic plasticity mechanisms of neurons. Replacement of insulin might represent a new strategic approach to counteract neurodegeneration. Here we review most of the available data regarding relationship between Alzheimer’s disease and insulin and propose new direction to deepen our understanding about insulin involvement in the pathogenesis of Alzheimer’s dementia.