The Novel Implication of Androgen in Diabetes-induced Alzheimer's Disease

ABSTRACT

Alzheimer's disease (AD) is characterized by the accumulation of amyloid beta (Aβ) and the hyperphosphorylation of tau protein in the brain, leading to the increase in inflammation and neuronal loss. Recently, evidences to support the association between type 2 diabetes mellitus (T2DM) and AD have markedly increased by clinical researches and experimental studies. Reduced insulin action and impaired glucose metabolism in the brain leads to diabetes induced AD. Androgen, a male sex hormone, was known to regulate inflammatory response, Aβ deposition in AD, insulin signaling, and synaptic plasticity in brain. Clinical studies demonstrated that androgen deficiency results in the increased risk of AD and its severe progression in male subjects. We reviewed the significant evidences to support that low testosterone levels are linked to diabetes-induced AD based on previous studies. Thus, we highlight the therapeutic potential of androgen in diabetes induced AD.