Study shows how stress may increase cardiovascular risk
A new study shows that increased activity in the amygdala (the part of the brain involved in stress) is associated with a greater risk of heart disease and stroke. Emotional stress has long been suggested as a risk factor for cardiovascular disease, but this study provides new insights into the possible mechanism by which stress can lead to cardiovascular disease in humans.
In the study, 293 patients were given a combined PET/CT scan to record their brain, bone marrow and spleen activity and inflammation of their arteries. The patients were then tracked for an average of 3.7 years to see if they developed cardiovascular disease. In this time 22 patients had cardiovascular events. Those with higher amygdala activity had a greater risk of subsequent cardiovascular disease and developed problems sooner than those with lower activity.
The researchers also found that the heightened activity in the amygdala was linked to increased bone marrow activity and inflammation in the arteries, and suggest that this may cause the increased cardiovascular risk. The authors suggest a possible biological mechanism, whereby the amygdala signals to the bone marrow to produce extra white blood cells, which in turn act on the arteries causing them to develop plaques and become inflamed, which can cause heart attack and stroke.
Writing in a linked Comment, Dr Ilze Bot, Leiden Academic Centre for Drug Research, Leiden University, The Netherlands, said, “These clinical data establish a connection between stress and cardiovascular disease, thus identifying chronic stress as a true risk factor for acute cardiovascular syndromes, which could, given the increasing number of individuals with chronic stress, be included in risk assessments of cardiovascular disease in daily clinical practice.”
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While more research and larger studies are needed to confirm the mechanism, the researchers suggest that these findings could eventually lead to new ways to target and treat stress-related cardiovascular risk and, in the future, could be included in risk assessments of cardiovascular disease in daily clinical practice.
Tawakol A, et al.Relation between resting amygdalar activity and cardiovascular events: a longitudinal and cohort study. Lancet 2017, published online 11 Jan www.thelancet.com/journals/lancet/article/PIIS0140-6736(16)31714-7/fulltext