Case–control Study to Explore the Relationship between Insulin Resistance and its Effect on the Level of Beta Amyloid for Alzheimer’s Patients with Type 2 Diabetes Mellitus

Alzheimer’s disease (AD) and insulin resistance (IR) share intersecting pathological pathways, with IR increasingly implicated in AD pathogenesis. Chronic hyperglycemia and IR may encourage the buildup of β-amyloid (Aβ), a defining feature of AD pathogenesis. This study aimed to examine the relationship between IR and its effect on the level of beta amyloid for Alzheimer’s patients with type 2 diabetes mellitus (T2DM). A case–control design study carried out among 106 T2DM patients with age group between (50 and 80 years), the study participant divided into three groups according to duration of disease, fasting blood glucose, hemoglobin A1c, fasting insulin, homeostasis model estimation of IR (HOMA-IR), HOMA-sensitivity (HOMA-S), and serum Aβ were measured. Using a random sampling technique from February to June 2025. The data collected were organized and analyzed using SPSS version 26, and the results were presented descriptively and inferentially. The Pearson’s correlation test was used to test the association between patient’s sociodemographic characteristics and their predictive factors. Higher FBG and HOMA-IR showed significant positive correlations with Aβ, indicating that chronic hyperglycemia and IR are linked to increased amyloid burden. Elevated insulin levels also correlated with Aβ, suggesting a role for hyperinsulinemia in impaired Aβ clearance. Conversely, HOMA-S% was negatively associated with Aβ, highlighting the protective role of insulin sensitivity. IR and poor glycemic control contribute to amyloid pathology in AD patients with T2DM, underscoring the importance of metabolic interventions in disease management.