Association between apolipoprotein E polymorphism and serum lipid and apolipoprotein levels with Alzheimer's disease

We have recently demonstrated that apolipoprotein E (APOE)-ɛ4 allele is a risk factor for Alzheimer disease (AD) in Tehran, Iran. The current study specifically aimed to examine whether APOE polymorphism in association with serum lipids-apolipoprotein level is a risk factor for AD in a population from Tehran, Iran. APOE polymorphism and plasma lipids, apoA1, apoB and lipoprotein (a) (Lp(a)) levels were determined in 94 AD patients and 111matched controls. Our study demonstrated a significant association between APOE polymorphism and the level of plasma lipids and apolipoprotein with AD in this population. The AD subjects had significantly lower apoA1 (p < 0.001) and HDL-C (p < 0.01) and higher apoB (p = 0.01) and LDL-C (p = 0.02) levels than that of the control group. The AD subjects carrying APOE-ɛ4 allele had lower plasma apoA1 (t = 5.2, p < 0.002) and HDL-C level (t = 2.7, p = 0.01) but had higher plasma apoB (t = −5.4, p < 0.002), LDL-C (t = −4.6, p = 0.005) and total cholesterol (TC) (t = −2.7, p = 0.01) than that of the non APOE-ɛ4 carriers. These results indicated that AD patients with APOE-ɛ4 allele has a distinct plasma lipid profile and carrier of this allele with low levels of apoA1 and HDL-C may be more susceptible to AD.