|Having a Sibling with Heart Disease Significantly Raises Personal
Heart Disease Risk
Having a sibling with a history of cardiovascular disease carries the same
or greater risk as having a parent with a history of the disease, according to
a new report from the long-standing Framingham Heart Study conducted by the National
Heart, Lung, and Blood Institute (NHLBI), a part of the National Institutes of
Health (NIH). Personal risk of having a cardiovascular event, such as a heart
attack, stroke, or peripheral artery disease, may be raised by as much as 45
percent in middle-aged people whose brother or sister has had such an event.
The study appears in the December 28, 2005, edition of the Journal of the
American Medical Association.
Even when data was adjusted for the fact that siblings may have similar lifestyle-related
risk factors and may be of similar ages, the risk associated with having a sibling
with cardiovascular disease remained high.
Physicians determine relative risk for cardiovascular disease by evaluating
known risk factors: family history of heart disease, age, high blood pressure,
high cholesterol, overweight, current or former smoking, physical inactivity,
and diabetes. While having a parent or sibling with heart disease has long been
suggested to increase risk, this study shows that having a sibling with heart
disease is a significant risk factor independent of other measures.
“This study illustrates that even people who are not at high risk based on their
own health status should talk to their doctors about the history of heart disease
in their families, among siblings as well as parents, and ask what they can do
to prevent a heart attack or stroke,” said NHLBI Director Elizabeth G. Nabel,
Researchers evaluated siblings from among 1188 men and 1287 women, all participants
in the Framingham Heart Study. Participants were at least 30 years old at the
time of a baseline examination, and were followed for eight years for the occurrence
of a cardiovascular disease event.
“We determined that one’s risk from a sibling with a cardiovascular disease
event remains elevated after taking into account age and other risk factors that
may cluster within families. The risk may be even higher than the risk related
to having a parent with cardiovascular disease,” said Joanne Murabito, MD, ScM,
of Boston University, the study’s lead author. “The risk from a sibling with
cardiovascular disease is significant even in persons with borderline elevated
levels of total cholesterol, levels at which physicians are often undecided about
The Framingham Study is one of the first studies to take an independent, unbiased
look at sibling risk. Unlike other studies of family history, which relied on
often-unreliable participant recall, this study evaluated independent data from
families within the 57-year-long observational study. Participants in this evaluation
were from the study’s Offspring group, the adult children of the original participants
who first enrolled in the 1940s and 1950s.
“Our findings suggests that taking an accurate family history should be a crucial
part of every physician’s method of assessing heart disease risk, and should
go beyond a simple ‘yes’ or ‘no’ question about the presence of disease in the
family,” said Dr. Murabito.
Patients should make the effort to collect medical history information from
their siblings and parents and make sure to inform their siblings if they have
a cardiovascular disease event such as a heart attack or stroke, she added.
“We believe that the reasons behind the strong association of risk between siblings
are environmental as well as genetic. In addition to sharing the same genetic
makeup, siblings may share similar dietary habits and physical activity patterns
in their early years while living in the same household. These habits may continue
on into adulthood when genetic factors begin to manifest,” Christopher O’Donnell,
MD, MPH, associate director of NHLBI’s Framingham Heart Study and the study senior
“While you can’t control your family history, there are many things you can
do to control your risk for heart disease, including keeping your blood pressure,
cholesterol and blood sugar under control, maintaining a healthy weight, avoiding
smoking, and getting regular physical activity,” said Dr. O’Donnell.
In May of 2004, the Framingham Heart Study research team demonstrated that having
a parent with a cardiovascular disease history doubles personal risk of the disease.
To schedule an interview, please contact the NHLBI Communications Office at
For more information about heart disease risk factors and the Framingham Heart
Study, visit the NHLBI Web site at www.nhlbi.nih.gov.
Information about taking a personal family history can be found at the U.S.
Surgeon General’s website “My Family Health Portrait” (https://familyhistory.hhs.gov/)
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agency for conducting and supporting basic, clinical, and translational medical
research, and it investigates the causes, treatments, and cures for both common
and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.