Amygdala Identified as Mediator Between Stress and Heart Problems
SCIENTISTS have for the first time identified the region of the brain that links stress in an individual to later experiencing adverse cardiovascular events such as heart attack and stroke.
The scientists have reported that the metabolic resting activity in the amygdala, which is an indicator of stress, is linked to a subsequent cardiovascular event. Their recently published paper discusses the findings of two studies completed at the Massachusetts General Hospital (MGH), Boston, Massachusetts, and the Icahn School of Medicine at Mount Sinai (ISSMS), New York City, New York, both located in the USA.
In the first study, conducted at MGH, researchers analysed the medical records and PET/CT brain imaging data from almost 300 individuals. None of the participants were found to have active cancer or cardiovascular disease at the time of imaging. The medical records also provided information from at least three additional clinical visits within 2–5 years after imaging. In the second study, conducted at ISSMS, the current levels of perceived stress was evaluated in 13 individuals with a history of post-traumatic stress disorder (PTSD) using brain image scanning.
The findings of the MGH study showed that the prior level activity in the amygdala provided a strong indication of the subsequent cardiovascular events that was experienced by 22 individuals. The association remained significant when controlling for traditional cardiovascular risk factors.
The levels of activity seen in the amygdala was also linked to the timing of cardiovascular events, with higher levels found in individuals experiencing events sooner than those with lower levels. In the ISSMS study, current stress levels were also reported as being strongly associated with amygdala activity.
Lead author of the paper, Dr Ahmed Tawakol, co-director of the Cardiac MR PET CT Program in the MGH Division of Cardiology, explained that these findings need to be confirmed in larger trials. However, Dr Tawakol felt that they do suggest opportunities to reduce cardiovascular risk attributable to stress, including through pharmacological manipulation. He added: “Increased stress associates with other diseases, such as cancer and inflammatory conditions, including rheumatoid arthritis and psoriasis. So it will be important to evaluate whether calming this stress mechanism benefits in those diseases as well.”
Jack Redden, Reporter