Stress tied to increased heart disease and stroke risk
Increase in perceived stress levels is associated with increased amygdalar activity, which is independently predictive of cardiovascular events, possibly through increased haemopoietic activity and arterial inflammation, a recent study suggests.
“Our findings raise the possibility that efforts to attenuate psychosocial stress could produce benefits that extend beyond an improved sense of psychological wellbeing,” said lead author Dr Ahmed Tawakol of Massachusetts General Hospital and Harvard Medical School in Boston, Massachusetts, US.
The longitudinal study included 293 participants (median age 55 years) in a clinical database who had undergone ¹⁸F-fluorodexoyglucose (FDG) PET/CT imaging and were followed up on cardiovascular disease (CVD) events. [Lancet 2017;doi:10.1016/S0140-6736(16)31714-7]
After a median follow-up duration of 3.7 years, amygdalar activity, a key element of the brain’s salience network which is involved in stress, was significantly associated with a more than 50 percent increased risk of CVD events, including heart failure, myocardial infarction, and cerebrovascular events (standardized hazard ratio [HR], 1.59; p<0.0001).
Amygdalar activity was also significantly associated with increased bone-marrow activity (p<0.0001) and arterial inflammation (p<0.0001), which were shown to mediate this association sequentially by mediation analyses.
“By demonstrating a significant pathway of increased amygdalar activity leading to increased bone-marrow activity leading to increased arterial inflammation leading to CVD event … our findings should prompt not only further investigation of the mechanisms that regulate this axis, but also ... suggest targets for novel therapeutic approaches to reduce cardiovascular disease risk,” said Tawakol and co-authors.
In another companion cross-sectional study involving 13 patients who also underwent psychometric analysis, an association was found between perceived stress levels and amygdalar activity (p=0.0485), arterial inflammation (p=0.0345), and C-reactive protein (p=0.0210).
Furthermore, there was also a significant association between amygdalar activity and arterial inflammation (p=0.0083).
“Chronic stress could be treated as an important risk factor for [CVD], one that is routinely screened for and effectively managed, like other major [CVD] risk factors,” said the researchers.
Noting the increasing number of people experiencing chronic stress, Drs Ilze Bot and Johan Kuiper from the Leiden Academic Centre for Drug Research at Leiden University in the Netherlands, in a separate commentary, agreed that chronic stress could be included in CVD risk assessments in daily clinical practice. [Lancet 2017;doi:10.1016/S0140-6736(17)30044-2]
“When encountering a patient with a stress syndrome, clinicians could reasonably consider the possibility that alleviation of stress might result in benefits to the cardiovascular system,” said Tawakol and co-authors.
As only participants who were indicated for and had undergone ¹⁸F-FDG PET/CT imaging were included in the study, the researchers acknowledged that the findings might not be generalized to other groups of patients.
“To infer causation, further longitudinal or interventional studies are needed,” they added.