The human risk of developing both Alzheimer’s disease and heart attack is genetically linked, leading the way to a genetic test earlier on in life, researchers from the University of Bologna wrote in the Journal of Alzheimer’s Disease. In fact, the authors claim the genetic test is already completed and currently being sold in the USA.

Immunologist, Federico Licastro, said:

    “..the tests could easily be also conducted wherever, using a simple blood test.”

Heart attacks and cardiovascular conditions are one of the main causes of premature death, and affect about 1 in every 8 people. According to the article, Alzheimer’s disease is the most common form of senile dementia. Approximately 20% of females and 10% of males are affected by it at the age of 85 years. Personalized tests are attractive prospects for several types of healthcare organizations.

The authors explained that some previous studies had suggested a possible association between heart attack and Alzheimer’s. We know that a higher percentage of individuals with coronary problems, such as hypertension, diabetes or high cholesterol, develop Alzheimer’s disease.

A number of genes which control cholesterol metabolism and inflammatory processes are somehow connected to heart attacks and Alzheimer’s.

In this study, Federico Licastro and team looked at the DNA of 1,800 individuals. 280 of them had had a heart attack while 257 had Alzheimer’s disease; the remaining 1,307 were healthy subjects (control group). They were looking out for genetic factors which might show a link between the two diseases.

They eventually found that congenital risks of being affected by one disease overlapped into a higher risk of developing the other. They found an overlap in risk among 40% of the Alzheimer’s patients and 30% of those who had had a heart attack.

The scientists had separated the subjects into six groups. Groups 1, 2, and 3 were “low risk groups”, with groups 2 and 3 being low risk and under 65 years of age. Groups 4 to 6 were “high risk groups”. Group 5 had only a heart attack risk.

They focused on groups 4 and 6.

  • Group 4 – individuals had a high risk of having a heart attack under the age of 40 and Alzheimer’s disease under the age of 65.
  • Group 6 – individuals had a high risk of developing a heart attack at the age of 40 to 54 and Alzheimer’s disease over the age of 65.

Licastro explained that it was in groups 4 and 6 that a common genetic predisposition was found.

Licastro said:

    “Until now, we only knew about individual genes linked to both diseases and this was not sufficient to develop an individual test for the risk. However, we have now been able to identify a genetic profile of several genes partially common to both diseases. This is the leap in quality that now enables us to conduct a test and assess a profile partially specific to both diseases.”

The genetic test can help doctors decide whether to monitor patients with frequent check-ups or order further diagnostic tests.

Licastro added:

    “The core of the genetic risk profile consists of genes that are involved in synthesizing and transporting cholesterol and in controlling for inflammation, which, therefore, appears to be at the root of both diseases.”

Therefore, doctors can carry out tests to identify Alzheimer’s and/or coronary diseases, as well as recommending lifestyle changes to prevent heart and circulation problems, and Alzheimer’s disease.

In a communiqué, the journal wrote:

    “However, the researchers understand that technical ingredient that brought about the success of the test is likely to be controversial. Indeed, to study the DNA of their patients, they had to resort to an innovative statistical technique called grade of membership analysis.”

This approach continues to be controversial within the international scientific community, the authors add. It is already being applied to the study of melanomas, schizophrenia and some other conditions.

Licastro said:

    “However, it is only by using such statistical analyses, that such diseases can be tested, conducting tests on only a few hundred cases. Classical statistics would require us to test 10, 12 or even 20 or 30 thousand cases.”

The researchers say they are currently trying to find more genetic links between Alzheimer’s and heart attack risk.

Source: Journal of Alzheimer’s Disease

Written by Christian Nordqvist