The Link Between Diabetes, Glucose Control, and Alzheimer's Disease and Neurodegenerative Diseases

Abstract

Largely as a result of increases in life expectancy in most countries, as well as changes in lifestyle over the last few decades, chronic diseases such as Type 2 diabetes (T2D) and dementia are increasing in prevalence. A wealth of evidence indicates a strong link between T2D and the development of neurodegenerative diseases such as Alzheimer's disease (AD). Although the precise mechanisms remain unclear, there is now strong evidence T2D and AD have many aspects in common, and that T2D can exacerbate neurodegenerative processes. Brain atrophy, reduced cerebral glucose metabolism, and central nervous system (CNS) insulin resistance are features of both AD and T2D. The T2D phenotype (glucose dyshomeostasis, insulin resistance, impaired insulin signalling) also promotes AD pathology, namely the accumulation of Aβ and hyperphosphorylated tau, and can induce other aspects of neuronal degeneration including inflammatory and oxidative processes. This chapter discusses the evidence and potential underlying mechanisms that link these two chronic diseases of ageing. The potential of common treatments for the management of diabetes as therapies for AD are also discussed.