Plasma oxidized low-density lipoprotein levels and risk of Alzheimer's disease

This study examines the association of plasma oxidized low-density lipoprotein (OxLDL) levels with all-cause dementia, including Alzheimer's disease (AD) and vascular dementia. Data are taken from the Canadian Study of Health and Aging, a population-based study of a representative sample of persons aged more than 65 years conducted from 1991 to 2002. The present study sample included 670 subjects of which, 155 developed all-cause dementia with 109 cases of AD and 32 of vascular dementia. In Cox regression models, no association between OxLDL and risks of dementia or subtypes was found. A triple interaction between OxLDL, sex, and history of cardiovascular disease on the risk of AD (p = 0.0077) was found. Increased levels of OxLDL were significantly associated with an increased risk of AD in men with a history of cardiovascular disease (hazard ratio = 1.11; 95% confidence interval 1.04-1.19); no association in women was found. These findings suggest that increased levels of OxLDL are not associated with the risk of dementia, AD, and vascular dementia. The association of OxLDL with AD in men with a history of cardiovascular disease merits further investigation.