Study finds link between heart disease and Alzheimer's disease in some patients

Washington DC: It turns out that genetics can predispose some people to both Alzheimer's disease and high blood lipid levels such as cholesterol, a common feature of cardiovascular disease.

Researchers from the medical schools of the University of San Francisco and the University of Washington have analyzed the genomic data of more than 1.5 million people, making it one of the largest studies ever done on the subject. Alzheimer's genetics.

More and more clinical and epidemiological evidence has revealed a link between heart disease and Alzheimer's disease, but a biological relationship between the two diseases has remained controversial. Many patients with Alzheimer's disease also show signs of cardiovascular disease. Post mortem studies have revealed that the brain of many Alzheimer's disease patients has signs of vascular disease that some scientists believe could be the cause of dementia.

These observations hinted at the hope of preventing Alzheimer's disease by treating cardiovascular symptoms, but the initial genetic studies and the failure of clinical trials of cardiovascular drugs called statins in Parkinson's disease. Alzheimer's have cast doubt on this possibility.

The new study, published in the journal Acta Neuropathologica, has shown that Alzheimer's disease and cardiovascular disease share a common genetics, raising new questions as to whether this shared biology could be targeted to slow down or prevent both diseases.

"These results imply that, regardless of the causes, cardiovascular and Alzheimer's pathologies co-occur, as they are genetically linked." That is, if you carry this handful of genetic variants you are at risk not only of heart disease but also of Alzheimer's, "said researcher Rahul Desikan.

The researchers used statistical techniques that allowed them to combine several large-scale genome wide association (GWAS) studies, a type of genetic study that makes it possible to establish genetic links between several genetic variants presenting a risk of cardiovascular disease and Alzheimer's disease. pathological states and widely shared variations of the genetic code.

The team of researchers was finally able to analyze the combined impact of these genetic markers on the risk of cardiovascular disease – based on five GWAS studies involving more than one million people – and on Alzheimer's risk – based on three GWAS studies involving nearly 30,000 patients. Alzheimer's patients and over 50,000 controls of the same age.

This analysis allowed the researchers to identify 90 points in the genome where specific variants of DNA increased the combined chances of patients developing Alzheimer's disease and elevated blood levels of lipid molecules, including HDL and LDL cholesterol and triglycerides, common risk factors for cardiovascular disease. .

The researchers confirmed that six of these 90 regions had very potent "genome-wide" effects on Alzheimer's disease and high levels of lipids in the blood, including several genes that had never before been found. related to the risk of dementia. These included several sites in the CELF1 / MTCH2 / SPI1 region on chromosome 11 that were previously linked to the biology of the immune system.

In contrast, although patients diagnosed with Alzheimer's disease also often have other cardiovascular risk factors, such as underweight rates of belly fat, type 2 diabetes and chest pain or other symptoms of coronary heart disease, the authors could find no obvious genetic overlap and these risk factors.

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