Abstract: Objective To investigate the level of insulin and amyloid beta-protein (Aβ) in patients with Alzheimer disease(AD). Methods The levels of fasting plasma glucose, true insulin, C-peptide, Aβ₄₀ and Aβ₄₂ in 70 healthy age-matched adults and 55 patients with AD were measured and analyzed. Results No differences were observed for the levels of fasting plasma glucose between AD groups and normal group (P>0.05). The level of the true insulin and C-peptide of the moderate/severe AD group were significantly higher than that of the normal control group(P<0.05), as well aw that of the Aβ₄₀ (P<0.05). The level of Aβ₄₂ of the mild AD group waw significantly higher than that of the normal control group(P<0.01). Conclusion Plasma insulin and Aβ are abnormal in AD, and they are related to severity of dementia.

Key words: Alzheimer disease, insulin, amyloid beta-protein