Serotonin may play role in hardening of the arteries

Findings may explain link between lifestyle and heart disease

A less active brain serotonin system is associated with early hardening of the arteries, according to a study presented today by University of Pittsburgh researchers at the 64th Annual Scientific Conference of the American Psychosomatic Society in Denver. These findings, which are the first to establish a link between serotonin messages in the brain and atherosclerosis, could lead to an entirely new strategy for preventing heart disease and stroke, say the researchers.

“Many of the known risk factors for heart disease and stroke – high blood pressure and cholesterol, obesity, diabetes, smoking and lack of exercise – can, to some extent, be controlled by our lifestyle choices,” said Matthew F. Muldoon, M.D., M.P.H., associate professor of medicine, University of Pittsburgh School of Medicine. “Until now, no one had studied the possibility that brain abnormalities could explain why some people make these poor lifestyle choices and have multiple risk factors for heart disease.”

In the study being presented today, which included 244 adult volunteers between the ages of 30 and 55 years, researchers measured serotonergic activity using a pharmacological approach and carotid artery thickness using ultrasonography. At the time of testing, participants were free of clinically evident vascular disease. Yet, those with low levels of serotonergic function were more likely to have thickening of the carotid artery than those with higher levels.

“If, through further studies, we can establish that risk factors for heart disease and stroke are, in part, controlled by the serotonin systems in the brain, it could open a whole new avenue for preventing heart disease and stroke,” said Dr. Muldoon.

Serotonin is a type of neurotransmitter, a chemical that sends messages between neurons in the brain. It is thought to play an important role in the regulation of mood, appetite and blood pressure. Previous studies by Dr. Muldoon and colleagues have found that people who get little exercise, are overweight, have high blood pressure, blood sugar and cholesterol have low levels of serotonergic function. A number of research studies have established a link between serotonin and mood. However, until now, the relationship between the serotonin system and atherosclerosis had remained unstudied.