A Pilot Study of the Association of Plasma Beta Amyloid 40/42 and Risk of Alzheimer's Disease in Mexican Americans

This research proposes to test plasma samples taken from elderly people of Mexican ancestry for these two biomarkers: AB40 and AB42. These tests were previously done in studies of people of European ancestry and showed that a higher ratio of 42 to 40 gave a significantly increased risk of developing of Alzheimer’s Disease.

Most of my research focuses on chronic neurodegenerative disease in aging populations, especially on Alzheimer’s disease and dementia. As an epidemiologist, I am primarily interested in risk factors that increase disease risk and on identifying ways to prevent the development of disease. My research is trying to find environmental factors or biomarkers that predict which people are more likely to get Alzheimer’s Disease. Evidence is mounting that exposures leading to Alzheimers occur in early or midlife. Research studies are important to find biomarkers that can predict an increased risk of Alzheimer’s Disease (AD). It is likely that prevention will be more effective in early stages of disease development. I also think that studying diverse populations can better help to identify both environmental and genetic risk factors that cause disease. Beta amyloid 40 (AB40) and 42(AB42) are potential biomarkers that could be used in screening for early AD and neurodegenerative processes. Before we can do that, we need to know if this will work in a variety of populations. This research proposes to test plasma samples taken from elderly people of Mexican ancestry for these two biomarkers: AB40 and AB42. These tests were previously done in studies of people of European ancestry and showed that a higher ratio of 42 to 40 gave a significantly increased risk of developing of Alzheimer’s Disease. The aims of this pilot project will be: 1. To describe plasma amyloid B42 and B40 in Mexican ancestry individuals, including overall levels, correlations with inflammatory markers (i.e. C-reactive protein, IL-6 and receptors, TNF-alpha and receptors), lipids, insulin, insulin degrading enzyme (IDE), body fat and other metabolic markers. 2. To estimate the risk of Alzheimer’s disease and CIND associated with AB40, AB42 and the ratio of AB42/AB40. 3. To evaluate whether the effects of AB40 and AB42 on AD or CIND are modified by presence of the ‘e4’ allele of ApoE lipoprotein. 4. To evaluate the influence of key biomarkers on the association between AB42 or 40 or the 42/40 ratio and AD and CIND as intermediate pathways or modifiers. Donor support for research into the causes and cures for Alzheimer’s Disease is critical because as the U.S. population ages, the percentage of funding available from other sources is not keeping up with the percentage of funding provided for other diseases that are generally found in younger people.