A literature review on the relationship between diabetes and dementia

Abstract Both diabetes mellitus and dementia are major chronic conditions prevalent in the aging population. The global demographic trend of aging is reinforcing this epidemiological correlation, with type 2 diabetes mellitus (T2DM) recognized as a major independent risk factor for Alzheimer’s disease (AD). Typically, the onset of T2DM precedes the manifestation of dementia. Molecular and neuroimaging studies consistently demonstrate that dysregulated glycemic control, encompassing both sustained hyperglycemia and recurrent hypoglycemic episodes, contributes substantially to subsequent cognitive decline. While cross-sectional clinical data robustly confirm this intricate relationship, long-term findings from longitudinal studies are often less conclusive, underscoring the intricate molecular biological interactions between the two conditions. The shared, multifactorial etiology is driven by common metabolic risk factors, including a sedentary lifestyle, overweight/obesity, dyslipidemia, and systemic insulin resistance (IR). Crucially, IR further accelerates AD pathogenesis by converging on shared pathways, specifically impaired insulin signaling, chronic cellular inflammation, and abnormal cerebral glucose metabolism. Consequently, effective prevention strategies against future dementia require proactive measures. These measures include regular and thorough health monitoring, early detection of abnormalities in blood glucose and lipid profiles, and prompt therapeutic interventions to optimize overall metabolic health.