Could ‘biomarkers’ be the key to predicting Alzheimer’s?

What is a biomarker??  Perhaps a useful tool to diagnose and predict dementia and cognitive decline, studies suggest. AstraZeneca defines the term as “a characteristic that is objectively measured and evaluated as an indicator of normal biological processes, pathogenic processes, or pharmacological responses to a therapeutic intervention.”

Because Alzheimer’s disease is complicated to assess or diagnose, researchers have been searching for “biological clues” for years.  

A study aimed at investigating a potential relationship between “plasma beta-amyloid 42 and 42/40 levels and cognitive decline in a large group of community-dwelling older adults without dementia” adds more support for the argument that biomarkers may be a useful tool for doctors.  The biomarkers used by this study: protein framgents.

The study found that older individuals who do not suffer from dementia, but lower levels of “blood plasma and biomarkers beta-amyloid 42/40 (protein fragments),” may be at an increased risk for experiencing cognitive decline. The relationship between cognitive decline and biomarker levels was more profound among less educated participants.  

"[The use of] biomarkers to identify elderly persons at risk of developing dementia could be useful for early prevention, if and when such interventions are available, and treatment," the author of the study explained. 

The study, published in the Journal of the American Medical Association (JAMA) was reported on by Senior Journal today.  That article is available here.  

 What does this mean for the future of biomarker research? 

"Future studies should further explore the use of plasma beta-amyloid as a biomarker, assess the mechanisms by which cognitive reserve modifies this association, and determine whether increasing cognitive reserve through interventions can reduce the risk of Alzheimer disease." 

In a different study, three specific proteins in cerebrospinal fluid were found to potentially “spot” Alzheimer’s disease.  That study appeared in the Archives of Neurology.  The BusinessWeek article that reported on this study is available here.  Of note, the Senior Director of Medical and Scientific Relations at the Alzheimer’s Association had this to say:

"This just reinforces the recommendation by [Alzheimer's working groups] saying that biomarkers can actually be incorporated today into clinical practice in order to add a certain piece to the diagnosis if patients are already presenting with something that looks like Alzheimer's."

Still another study carried out by the Texas Tech University Health Sciences Center and the Texas Alzheimer’s Research Consortium, reported by Ivanhoe Newswire, found that blood serum biomarkers PLUS other clinical information could be used to more accurately classify patients with AD.  Commenting on the importance of such studies, the authors say: "There is clearly a need for reliable and valid diagnostic and prognostic biomarkers of Alzheimer's disease, and in recent years, there has been an explosive increase of effort aimed at identifying such markers."

The Texas Tech study authors appear optimistic:

"With the rapidly evolving technology and the analytic techniques available, Alzheimer's disease researchers now have the tools to simultaneously analyze exponentially more information from a host of modalities, which is likely going to be necessary to understand this very complex disease."

In other Alzheimer's related news, CNN reported that Big Pharma companies are uniting to share data:



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Good cholesterol linked to reduced Alzheimer’s risk

Alzheimer’s disease is the 7^th leading cause of death and costs about 172 billion dollars annually.[1] Due to the disease’s debilitating nature, more than 10 million caregivers of individuals with the disease are unpaid family members, friends, or volunteers. For these reasons, it is no surprise that research and medical trials are ongoing to combat the disease. Just as important as research from the scientific community, is knowledge of the steps people can take to reduce their risk for developing the disease. The December issue of Archives of Neurology reported that a high level of “good” cholesterol has been found to be linked to a reduced risk for developing Alzheimer’s.[2]

Senior Journal reported on the study from the Archives, explaining that researchers studied 1,130 healthy adults from a pool of Medicare recipients from New York, to study a possible relationship between HDL and Alzheimer’s symptoms.

While the researchers conclude that higher HDL cholesterol was associated with a lowered risk of developing Alzheimer’s disease, they also note that “[a]n important consideration in the interpretation of the results is that it was conducted an urban multiethnic elderly community with a high prevalence of risk factors for mortality and dementia.” In other words, as applied to younger individuals, the correlation between HDL and reduced risk for developing Alzheimer’s is unclear.

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[1] Alz.org, Alzheimer’s Facts and Figures (2010), available at http://www.alz.org/alzheimers_disease_facts_and_figures.asp

[2] Senior Journal notes that the study was supported by the National Institute on Aging, the Charles S. Robertson Memorial Gift for Research in Alzheimer’s Disease and the Blanchette Hooker Rockefeller Foundation.

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