Scientists discover initial links between cardiovascular risk and brain metabolism

The links between cardiovascular disease and cognitive impairment begin years before the first clinical symptoms of any of the conditions appear. In a study conducted at the National Center for Investigaciones Cardiovasculares (CNIC) in partnership with Banco Santander and neuroimaging experts from the Barcelonaβeta Brain Research Center (BBRC, the research center at Fundación Pasqual Maragall), the researchers identified a link between brain metabolism , cardiovascular risk and atherosclerosis during middle age, years before the first appearance of symptoms.

The report, published in the Journal of the American College of Cardiology (JACC), is important because it suggests that intervention in a modifiable condition (cardiovascular disease) can prevent the development of dementia, a disease for which there is currently no cure.

Dr. Valentín Fuster, director general of CNIC and Mount Sinai Heart, chief physician at Mount Sinai Hospital and lead author of the study, said: “While everyone knows about the importance of taking care of ourselves and controlling cardiovascular risk factors in to avoid a heart attack, the association of these same risk factors with cognitive decline can increase awareness of the need to acquire healthy habits from the earliest stages of life ”.

In addition, the results provide even more support for the importance of implementing primary cardiovascular prevention strategies in middle age as a valuable therapeutic approach to slow or even stop brain changes that could contribute to future cognitive decline.

Cognitive impairment

The advanced stages of vascular disease and dementia usually occur together, but until now this association has not been documented in the early stages. The study coordinated by the CNIC, led by Dr. Marta Cortés Canteli, shows that in middle age, years before any clinical signs appear, atherosclerosis and cardiovascular risk factors already show an association with low metabolism in regions of the brain involved in the future development of dementia. especially Alzheimer’s disease.

The advanced stages of neurodegenerative and vascular diseases often occur together, and research in recent years has established close links between cognitive decline and a number of cardiovascular risk factors, including hypertension, obesity and high cholesterol.

Using advanced positron emission tomography (PET) images, the research team quantified brain metabolism in more than 500 participants in the PESA-CNIC-Santander study. The participants had an average age of 50 years and had no symptoms, but already had evidence of atherosclerosis in their arteries.

PESA-CNIC-Santander, led by Dr. Valentín Fuster, is a prospective study of more than 4000 asymptomatic middle-aged participants who have been thoroughly evaluated for the presence and progression of subclinical atherosclerosis since 2010.

The new study reveals a link between the increased risk of a cardiovascular event and low brain metabolism. “When brain metabolism declines, the brain’s ability to deal with adverse events can be compromised. Depending on the area of ​​the brain affected, this can lead to a number of different problems,” explained study co-author Dr. Cortés Canteli , CNIC researcher and Companion Miguel Servet.

Cardiovascular risk

“We found that a higher cardiovascular risk in apparently healthy middle-aged individuals was associated with lower brain metabolism in parietotemporal regions involved in spatial and semantic memory and in various types of learning,” said Dr. Cortés Canteli. Dr. Juan Domingo Gispert, head of the BBRC Neuroimaging group, noted that “the areas of the brain that show low metabolism in participants at higher cardiovascular risk are the same areas affected in Alzheimer’s disease, suggesting that these individuals may be vulnerable above normal to this disease. “

“We think that cardiovascular risk factors that affect the large vessels that carry blood from the heart to the brain also affect the small vessels in the brain,” said Dr. Fuster.

The study is the largest of its kind to date in a healthy middle-aged population and could signal a paradigm shift in understanding the links between vascular and brain diseases, say the authors.

Among the modifiable cardiovascular risk factors most closely associated with a reduction in brain metabolism, the researchers saw the greatest effect with hypertension. “We found that the same risk factors that damage the heart and the great arteries, and especially hypertension, are closely linked to the decline in brain metabolism years before the onset of symptoms,” said Dr. Fuster.

Atherosclerotic plaques

The research team also found that a greater number of plaques in the carotid arteries, which carry blood to the brain, were associated with lower brain metabolism in areas of the limbic system and the parietal lobe, both closely linked to the development of Alzheimer’s Disease. .

“The next step will be to determine whether individuals with subclinical atherosclerosis in the carotid arteries and low brain metabolism at age 50 experience cognitive decline 10 years later,” said Dr. Cortés Canteli.

Dr. Juan Domingo Gispert noted that “there is abundant evidence linking cardiovascular risk factors and Alzheimer’s disease. If we can gain a more accurate understanding of this relationship in the stages of asymptomatic disease, we will be in a position to design new strategies to prevent Alzheimer’s, matching the success of current strategies to prevent cardiovascular disease. “

These results will be a great stimulus for the implementation of early intervention strategies to reduce the incidence of cognitive decline in old age.

Supplied by Centro Nacional de Investigaciones Cardiovasculares Carlos III (FSP)