Heart Risk Tied to Blood Type

Rarest AB blood type linked to higher risk of coronary heart disease

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) New research indicates that a person's blood type appears to influence coronary heart disease risk. Individuals with type A and B are at a higher risk, while those with rarer type AB are at the greatest risk.

Blood typing specifies which particular blood type a person has based on which proteins are present in red blood cells. It is checked through a simple blood test.

Knowing your blood type is critical in the event that a transfusion or blood products are required.

Compared to those with type O blood, individuals with type AB are at a 23 percent increased risk of coronary heart disease. Only about 7 percent of the population have this blood type.

"Ask your doctor your blood type."

Lu Qi, MD, PhD, the study’s senior author and an assistant professor in the Department of Nutrition at the Harvard School of Public Health, noted that while people can't change their blood type, the findings identify patients at a higher risk of heart disease.

He encourages patients to know their blood type so that they can reduce their risk by avoiding smoking, eating healthy and exercising if they are at a higher risk based on their blood type.

Researchers reviewed two large studies that included 62,073 women from the Nurses' Health Study and 27,428 men and women participating in the Health Professionals Follow-up Study. The patients, mostly white and between the ages of 30 and 75, were followed for at least 20 years.

In addition to blood type, investigators examined age, gender, race, diet, body mass index, smoking, menopause status and medical history. The numbers of various blood type included in the study mirrored the general population. Researchers did not examine why the risk was higher for individuals with certain blood types.

Compared to type O blood, individuals with type B are at an 11 percent increased risk of coronary heart disease, while type A carries a 5 percent increased risk. Type AB was associated with the highest risk.

Though investigators didn't identify the reason for the varying risk levels, they did suggest that type AB is linked to inflammation, which affects blood vessel function, while type A is associated with higher levels of "bad" LDL cholesterol. A substance may help promote blood flow and clotting in individuals with type O blood.

Additional studies would be needed to determine whether lifestyle changes affect individuals with different blood types in the same way, Dr. Qi said.

The study, funded by the National Institutes of Health, the American Heart Association Scientist Development Award and the Boston Obesity Nutrition Research Center, was recently published in Arteriosclerosis, Thrombosis and Vascular Biology, an American Heart Association journal.

Reviewed by: 
Review Date: 
August 14, 2012
Last Updated:
August 15, 2012