"Stress gene" increases risks of heart attack by 40 percent

"Stress gene" increases risks of heart attack by 40 percent, new study suggests.

The study authors say they’ve found a biological explanation for why some people are predisposed to develop heart disease or die early from a stroke or heart attack, CBS News reports.

The study is based on identification of a genetic variant called a single nucleotide polymorphism - SNP, in a DNA chain. Essentially, SNP is when one letter in a DNA sequence is swapped with another letter, which leads to a change in function. In this case, the function of the gene is changed to cause a hyperactive reaction to stress.

The researchers point out that a study last year found men with these gene variants had twice as much cortisol, a hormone related to stress, in their blood while under stress compared to men without the variant. 

They conducted a genetic analysis of more than 6,100 people who underwent cardiac catheterization procedures, two-thirds of whom were male. In that procedure, a long, flexible tube is threaded through a blood vessel in the arm so doctors can perform tests or treatments that directly target the bloodstream.

They found the overactive stress gene in 13 percent of the patients. After tracking them for six years, the researchers discovered the genetic trait raised risk for heart attack and early death by 40 percent. This was the case even after ruling out other factors like age, obesity, smoking history and severity of their heart disease.