A genetic variant known to make some people hypersensitive to stress is also linked to a 38 percent increased risk of heart attack or death in patients with heart disease, according to researchers at Duke Medicine.
“We’ve heard a lot about personalized medicine in cancer, but in cardiovascular disease we are not nearly as far along in finding the genetic variants that identify people at higher risk,” said senior author Redford B. Williams Jr., M.D., director of the Behavioral Medicine Research Center at Duke University School of Medicine.
“Here we have a paradigm for the move toward personalized medicine in cardiovascular disease.”
The researchers built on previous work at Duke and elsewhere that identified a variation in a DNA sequence, known as a single nucleotide polymorphism (SNP), where one letter in the genetic code is swapped for another to change the gene’s function. The team focused on a particular SNP that occurs on the gene that makes a serotonin receptor and causes a hyperactive reaction to stress.
In a previous study, researchers found that men with this genetic variant had twice as much cortisol in their blood when exposed to stress, compared to men without the variant. The stress hormone cortisol is produced in the adrenal gland to support the body’s biological response when reacting to a situation that causes negative emotions.
“It is known that cortisol has effects on the body’s metabolism, on inflammation and various other biological functions, that could play a role in increasing the risk of cardiovascular disease,” said lead author Beverly H. Brummett, Ph.D., associate professor of psychiatry and behavioral sciences at Duke.
“It has been shown that high cortisol levels are predictive of increased heart disease risk. So we wanted to examine this more closely.”
“The exciting part to me this is that this genetic trait occurs in a significant proportion of people with heart disease,” Brummett said. “If we can replicate this and build on it, we may be able to find ways to reduce the cortisol reaction to stress – either through behavior modification or drug therapies – and reduce deaths from heart attack.”
Researchers used a database to run a genetic analysis of more than 6,100 white participants, two-thirds of whom were men, and one-third women. About 13 percent of this group had the genetic variation for the overactive stress response.
Patients who carried the genetic variation had the highest rates of heart attacks and deaths over the median follow-up time of six years. Even after adjusting for age, obesity, smoking history, other illnesses and the severity of their heart disease, the genetic trait was linked to a 38 percent increased risk of heart attack and death.
“We plan to study this further,” Williams said. “But what this work suggests already is that we have a found genetic variant that can be easily identified, so we can begin to develop and test early interventions for those heart patients who are at high risk of dying or having a heart attack.”
Source: PLOS One