By Steven C. Moyo, M.D.
A gene mutation can increase your risk of heart attack and death as much as smoking does, new research suggests.
Duke University researchers reported today finding a link between a gene mutation known to increase the body's response to stress and heart health. They found in a study of more than 6,000 patients with heart disease, carriers of this genetic mutation had a 38 percent increased risk of heart attack or death.
Genetic mutations are not just the stuff of movies and comic books. They are changes in our DNA code that affect the color of our eyes, our risks for cancer - and, as this study shows, even our response to stress.
When we are stressed, it sets off a chain reaction of chemical signals in our bodies. The first of these is the release of a chemical called serotonin in the brain - something that happens as soon as we get yelled at by our boss, for example, or get cut off in traffic. This release of serotonin lights the fuse for the explosive cascade of chemicals that follows, eventually leading to increased levels of cortisol in our system.
What this gene mutation does is produce a slightly different serotonin receptor in the brain - one that causes an even greater than normal release of cortisol in response to stress.
This is bad news for our hearts. Specifically, increased cortisol has been shown to be associated with higher levels of calcium deposits in the heart's blood vessels, and blockage of these vessels is linked to increased risk of heart attack and death.
"Men with this gene mutation have been shown to have a two- to three-times larger cortisol response to stress," said study investigator, Dr. Redford Williams, professor of medicine at Duke University. This higher-than-normal cortisol response from this gene, he said, boosts the risk of heart attack or death. Williams added that more than one in eight men and up to 2 percent of women in the general population are thought to carry this gene mutation, and that the increased risk associated with this gene is comparable to the increased risk associated with a smoking habit.
Williams said he hopes the findings will shed further light on the role of genes in stress-related heart ills - a hope shared by heart disease experts not involved with the study.
"This is a very interesting study that raises new questions about genetic determinants of heart disease risk," said Dr. Randall Thomas, associate professor of medicine at the Mayo Clinic. "However, additional studies will need to be done to verify and expand upon these findings before this [information] would be ready for clinical use."
Yet, Williams said he hopes that a clinical application is in the future for this finding.
"The longest journey begins with a single step," Williams said. "This research is one of those small steps … and is important in realizing the promise of personalized medicine in heart disease."
While we are still far away from fully realizing the clinical potential of such a finding, Williams notes that this research adds to the promise of more personalized, gene-centered medical care. Since heart disease is the number one killer of Americans, finding new ways to identify people at increased risk of serious events from heart disease is important.
In addition to controlling our stress levels, of course, there are other things that we can all do to improve our odds against heart disease. The most important things one can do are to avoid smoking, engage in regular exercise, and eat a healthy diet.