Blood type could help identify heart disease risk

Educating patients about their blood type and the health risks associated with it could help prevent cardiovascular disease, a study says.

People with blood type AB (7% of the U.S. population) have a 23% increased risk of developing coronary heart disease compared with those who have type O blood, said a study published online Aug. 14 in Arteriosclerosis, Thrombosis and Vascular Biology.

Researchers didn’t examine the biological processes behind blood type and heart disease risk. But they said type AB is linked to inflammation, which might affect the function of blood vessels. Blood type A is associated with higher levels of low-density lipoprotein cholesterol.

“While people cannot change their blood type, our findings may help physicians better understand who is at risk for developing heart disease,” said study senior author Lu Qi, MD, PhD, assistant professor in the Dept. of Nutrition at Harvard School of Public Health in Boston.

A patient’s blood type also can be used to help tailor preventive measures for cardiovascular disease, Dr. Qi said. For example, in a person with type A blood, decreasing cholesterol intake might be the best way to lower the risk of coronary heart disease.

Cardiovascular disease is the leading cause of death among men and women in the U.S., and coronary heart disease is the most common type of the condition. In 2008, there were 405,309 deaths due to coronary heart disease, according to the Centers for Disease Control and Prevention.

Researchers examined blood type and medical information on 62,073 women who participated in the Nurses’ Health Study and 27,428 men from the Health Professionals Follow-up Study. Participants were between 30 and 75 years old and were followed for at least 20 years. Researchers excluded adults who had reported having cancer, coronary heart disease or stroke, among other conditions.

Forty-three percent of people assessed in the Arteriosclerosis, Thrombosis and Vascular Biology study had type O blood. The frequency of blood types A, B and AB among women were 36%, 13.3% and 8%, respectively. Among men, 37.2% had type A blood, 12.3% type B and 8% type AB (link).

During follow-up, coronary heart disease was confirmed in 2,055 women and 2,015 men. Participants with B blood type had an 11% increased risk of developing the condition, and those with type A had a 5% greater risk than people with type O blood.

Because most of the study participants were white, further research is needed to determine whether the findings apply to different ethnic groups, the study said.

“But we can’t exclude the possibility that the association also exists in other populations,” Dr. Qi said.