Inflammation, Defective Insulin Signaling, and Mitochondrial Dysfunction as Common Molecular Denominators Connecting Type 2 Diabetes to Alzheimer Disease

A growing body of evidence supports an intriguing clinical/epidemiological connection between Alzheimer disease (AD) and type 2 diabetes (T2D). T2D patients have significantly increased risk of developing AD and vice versa. Recent studies have begun to reveal common pathogenic mechanisms shared by AD and metabolic disorders, notably obesity and T2D. In T2D and obesity, low-grade chronic inflammation is a key mechanism leading to peripheral insulin resistance, which progressively causes tissue deterioration and overall health decline. In the brain, proinflammatory signaling was recently found to mediate impaired neuronal insulin signaling, synapse deterioration, and memory loss. Here, we review evidence…