WEDNESDAY, Feb. 27 (HealthDay News) -- When a brother or sister dies -- especially from a heart attack -- the risk of a surviving sibling also dying from a heart attack increases sharply in the following years, a large new study from Sweden suggests.
Chronic stress or lifestyle choices like drinking, smoking, unhealthy diet and lack of exercise may follow the loss of a sibling, increasing the risk of a heart attack over time, the researchers said.
"Health care providers should follow bereaved siblings to help recognize signs of acute or chronic psychosocial stress mechanisms that could lead to heart attack," said lead researcher Mikael Rostila, an associate professor at Stockholm University and the Karolinska Institute.
"We might be able to prevent heart attacks and other heart-related conditions by treating these siblings early on and recommending stress management," he added.
Reasons for the association between a sibling's death and the death of a brother or sister years later aren't clear, Rostila noted. And although the study showed an association between a sibling's heart attack death and heightened death risk, it did not establish a cause-and-effect relationship.
"More detailed information from medical records, shared childhood social environment and family characteristics, and data on personal and relational characteristics is needed to uncover the mechanisms causing the association between sibling death and heart attack," Rostila said.
The report was published in the Feb. 27 issue of the Journal of the American Heart Association.
To see the effect of a sibling's death on their other siblings, Rostila's team collected data on more than 1.6 million people in Sweden, aged 40 to 69.
They found the risk of dying from a heart attack increased 25 percent among surviving sisters and 15 percent among surviving brothers compared to people who had not lost a sibling. If their brother or sister died of a heart attack, risk of also dying from a heart attack in the following years increased by 62 percent among women and 98 percent among men, Rostila's team found.
Death from a heart attack was not likely to happen immediately after siblings died, the researchers said. Rather, the risk rose in the four to six years after a sibling's death among women and in the two to six years afterward among men, they found.
"This is a red flag for families," said Dr. Stephen Green, associate chairman of the department of cardiology at North Shore University Hospital, in Manhasset, N.Y. "We know that heart disease is genetic and environmental and typically siblings and family members share the same gene pool, but also share the same bad habits."
Many siblings whose brother or sister died from a heart attack have undiagnosed heart disease, Green said.
If you -- or someone you know -- has a family member with a history of heart disease or heart attack, or a family member who died from heart disease, it is important to talk with your primary care doctor or a cardiologist to make sure it doesn't happen to you, Green said.
SOURCES: Mikael Rostila, Ph.D., associate professor, Stockholm University/Karolinska Institute, Sweden; Stephen Green, M.D., associate chairman, department of cardiology, North Shore University Hospital, Manhasset, N.Y.; Feb. 27, 2013, Journal of the American Heart Association