Research Updates

in Newsletter
March 20th, 2010

Activities of Daily Living in Mild Cognitive Impairment

Dr. Angela Jefferson and colleagues recently investigated relations between brain magnetic resonance imaging markers of cerebrovascular disease and Alzheimer’s disease (AD) in individuals with mild cognitive impairment (MCI). Preliminary findings from the Heart & Brain Aging Study suggest increased white matter hyperintensities, but not hippocampal volume, are associated with worse functional status. These findings, which were presented at the recent International Neuropsychological Society meeting, are consistent with evidence that executive dysfunction, rather than memory impairment, is associated with functional decline and conversion from MCI to AD.

Blood Pressure Treatment and Dementia Prevention

Dr. Benjamin Wolozin recently published a study in British Medical Journal showing that combined use of two blood pressure medications that prevent angiotensin signaling (that is, angiotensin receptor blockers and ACE inhibitors) is associated with a 50% lower incidence of dementia and, for those with dementia, a 70% lower rate of nursing home admission. Previous studies indicate that angiotensin receptor blockers are particularly effective at preventing vascular damage induced by amyloid β, a protein that accumulates in AD. Dr. Wolozin’s findings suggest that this combination of blood pressure medications protects against cognitive decline by reducing neuronal damage associated with vascular dysfunction and stroke.

“I know what you told me, but this is what I think”

Dr. Robert Green, Erin Linnenbringer, MS, CGC, and the REVEAL Study Group recently published a study in Genetics in Medicine evaluating AD risk perceptions among individuals who accurately recalled their genetic-based risk assessment. As part of the REVEAL Study, 246 unaffected relatives of individuals with AD were given a genetics-based risk assessment for AD. Out of 158 individuals who accurately recalled the risk assessment they were given by study investigators, nearly half believed their actual risk was different than what they had been told. These results indicate that individuals who are able to accurately recall their risk assessment do not necessarily take communicated risk estimates at face value.

Impact of AD Genetic Risk Disclosure on Dietary Supplement Use

Dr. Robert Green, Dr. Jacqueline Vernarelli, and the REVEAL Study Group recently published a study in the American Journal of Clinical Nutrition on the impact of risk disclosure for AD on dietary supplement use. They found that after receiving a risk assessment for AD, 16% of all participants in the study reported a change in dietary supplement use. Individuals who learned they carry the AD risk-increasing apolipoprotein (APOE) ε4 genotype were more likely to report an increase in dietary supplement use than those who learned they were APOE ε4-negative.

Late-Life Depression and AD

It is well-known that APOE ε4 is a major genetic risk factor of late onset AD. However, 50% of AD patients do not carry APOE ε4, suggesting other risk factors in the pathogenesis of AD. Using a homebound elderly population in the Boston area, Dr. Wendy Qiu and her research team have found that non-APOE ε4 carriers with depression have similar biomarkers in their blood (for example, low Aβ42 and a high Aβ40/Aβ42 ratio in plasma) as APOE ε4 carriers. Because a high percentage of these depressed elderly individuals have cognitive impairment, the researchers hypothesize that amyloid-associated depression defined by low plasma Aβ42 and high plasma Aβ40 might be a prodromal stage of AD even in the absence of APOE ε4. The finding was recently published in Alzheimer’s Disease & Associated Disorders and may offer an additional target for the prevention and intervention of AD. Dr. Qiu has received an R01 grant from the National Institute on Aging to further study the relationship between late-life depression and AD.