Objective To test amyloid beta protein(Aβ)40 and Aβ42 levels in CSF and apolipoprotein E (ApoE) genotype in patients with Alzheimer's disease(AD) and study whether or not the Aβ is related to the severity of dementia and the genotypes of ApoE.Methods 48 AD patients including 27 cases of mild type and 21 cases of serious type and 35 normal controls were selected.Aβ40 and Aβ42 in CSF and ApoE genotype were analyzed.Results Aβ40 levels were ( 12.3 ±4.6) μg/L,( 11.7 ±4.1 ) μg/L,( 12.6 ±4.9) μg/L and ( 11.0 ±3.7) μg/L(t = 1.377,0.705 and 1.385 ,all the p values were greater than 0.05) and Aβ42 levels were ( 105.3 ±25.4) ng/L,(110.7 ±21.7) ng/L,(96.9 ±23.9) ng/L and (123.5 ±29.6) ng/L(t=3.006,2.832,and 3.488,all the p values less than 0.01 ),in AD group,mild AD group,moderate to serious AD group and normal controls,respectively.Aβ40 levels were (11.9 ± 5.2) μg/L vs.(10.5 ± 3.8) μg/L in AD and controls with ApoEε4(t=0.696,P＞0.05) and (12.6 ±4.5) μg/L vs.(11.4 ±3.4) μg/L without ApoEε4(t = 1.008,P＞0.05).Aβ42 levels were (99.7 ± 23.8) ng/L vs.( 129.6 ± 31.0) ng/L in AD and controls with ApoEε4( t =1.632,P ＞ 0.05 ) and ( 110.4 ± 28.4) ng/L vs.( 129.6 ± 31.0) ng/L in those without ApoEε4 ( t = 2.110,P ＜0.05 ).Conclusions The CSF level of Aβ is abnormal in AD,and it is related to the severity of the disease and the ApoE genotypes.

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.