A genetic variant occurring in a significant number of people with heart disease appears to raise the odds for heart attack or death by 38 percent, a new study suggests.
This "stress reaction gene", which Duke University scientists previously linked to an overproduction of cortisol, a stress hormone that can affect heart risks, was found in about 17 percent of men and 3 percent of women with heart disease.
The new finding, also from Duke researchers, offers a potential new explanation for a biological predisposition to heart disease and early death, the study authors said. The research may eventually lead to personalised therapies for heart disease patients.
"This is very exciting, but it's very preliminary. It certainly merits further investigation," said study author Beverly Brummett, an associate professor of psychiatry and behavioural sciences at the Duke University School of Medicine. "Down the line, if the findings were replicated, then the next step would be to test people [on a widespread basis] for the gene and watch them more closely."
The study was published in the journal PLoS One.
Number one killer
Heart disease is the number one killer of Americans. Its most common cause is the narrowing of coronary arteries, which can lead to heart attacks, according to the U.S. National Library of Medicine. About 600 000 people in the United States die each year due to heart disease.
Brummett and her colleagues ran genetic analyses on more than 6100 white men and women who were part of a large database of Duke heart catheterisation patients. Two-thirds of the participants were men. Patients carrying the genetic variant experienced the highest rates of heart attacks and deaths over an average follow-up period of six years.
Despite adjusting the results for heart disease risk factors such as age, obesity and smoking history, the genetic trait was associated with a 38% higher risk of heart attack and death. This kind of association, however, does not necessarily prove a cause-and-effect relationship.
Dr Nieca Goldberg, medical director of New York University's Women's Heart Programme, said the research was "very exciting".
"There's a lot of talk going on about personalised medicine and we're trying to really individualise our therapies," said Goldberg, who was not involved in the study.
"This identifies a genetic trait that predisposes people to heart disease, and once this is tailored a little more and we have more research, it would be exciting if this [genetic test] became commercially available," said Goldberg, who is also a spokesperson for the American Heart Association.
Goldberg said it would be useful to know how frequently the gene variant occurs in other ethnic groups, such as blacks, Asians and Latinos, since all of the study participants were white.
The American Heart Association offers information on various types of heart disease.