No abstract

Polymorphisms of the cholesterol-24S-hydroxylase (CYP46A1) and apolipoprotein E (APOE) genes are risk factors for Alzheimer's disease (AD). Plasma level of 24S-hydroxcholesterol (24-OHC), the metabolite of cholesterol, is thought to correlate with AD. The present study investigated the correlation between these genetic factors and blood 24-OHC and amyloid-beta (Aβ) levels in AD patients. Association analysis, logistic regression, and linear regression were used to analyze the correlation of CYP46A1 and APOE genotypes with blood 24-OHC and Aβ levels and AD risk. We found that the APOEε4 alleles were significantly higher in patients with AD and there was a potential synergistic interaction between the CYP46A1 C allele and APOEε4 allele in AD. Blood 24-OHC level and Aβ level were significantly higher in AD patients than controls, indicating 24-OHC could be a marker in AD diagnosis. However, AD patients with the CYP46A1 TT, but not CC, genotype had higher 24-OHC levels, which indicated that there may be other mechanisms in the relationship between CYP46A1 polymorphisms and AD.

Background and PurposeThis study investigated the contribution of white-matter hyperintensities (WMH) and lacunar infarcts (LI) to the risk of Alzheimer's disease (AD) in an elderly cohort in China.MethodsOlder adults who were initially cognitively normal were examined with MRI at baseline, and followed for 5 years. WMH were classified as mild, moderate, or severe, and LI were classified into a few LI (1 to 3) or many LI (≥4). Cognitive function was assessed using the Mini Mental State Examination and the Activities of Daily Living scale.ResultsAmong the 2,626 subjects, 357 developed AD by the end of the 5-year follow-up period. After adjusting for age and other potential confounders, having only WMH, having only LI, and having both WMH and LI were associated with an increased risk of developing AD compared with having neither WMH nor LI. Moderate and severe WMH were associated with an increased risk of developing AD compared with no WMH. Furthermore, patients with many LI had an increased risk of developing AD compared with no LI.ConclusionsHaving moderate or severe WMH and many LI were associated with an increased risk of developing AD, with this being particularly striking when both WMH and LI were present.

No abstract