Genes Affect Blood Pressure Risk

Lifestyle Factors Mix With Genes to Raise Risk of High Blood Pressure

By Jennifer Warner
WebMD Health News
Reviewed by Elizabeth Klodas, MD, FACC

WebMD News Logo June 16, 2009 -- Genes may help explain why some people are more or less susceptible to the negative effects of drinking, smoking, or lack of exercise on their blood pressure.

A new study shows lifestyle factors interact with genes to influence blood pressure levels and increase or decrease the risk of high blood pressure.

For example, people with a genetic predisposition to high blood pressure may benefit more than others by following a healthy lifestyle, such as not smoking, limiting alcohol use, and exercising regularly, because their genes magnify the negative effects of these factors.

"The three lifestyle characteristics are well-known risk factors for high blood pressure," says researcher Nora Franceschini, MD, assistant professor of epidemiology at the University of North Carolina in Chapel Hill, in a news release. "What's new is that we are showing that these behaviors interact with your genes to influence blood pressure levels. Drinking, smoking and exercise habits can be modified, which would, in turn, influence the risk of developing hypertension, even in people who are predisposed to the condition."

Lifestyle Affects Inherited Risk

The study, published in Circulation: Cardiovascular Genetics, analyzed genetic and medical data collected in the ongoing Strong Heart Family Study of American Indians. Using information from 3,665 participants ages 14 to 93, researchers looked at how inherited genetic patterns influenced high blood pressure risk among those with different lifestyles and education levels.

The results showed that about 15% of the variation in diastolic values (the bottom number in a blood pressure reading) was due to genes.

However, researchers also found an interaction between genetic and lifestyle factors on blood pressure, including:

• A link between cigarette use and gene interaction on diastolic blood pressure in comparing smokers and those who had never smoked.

• Evidence that blood pressure among drinkers is affected by different genes in former and never drinkers.

• Evidence that an individual's physical activity level influences the genetic effects on blood pressure.

"So your level of blood pressure is influenced by your genes, whether you are a smoker or not, are physically active or not, or drink alcohol or not," says Franceschini. "But those habits can still influence a person's susceptibility to the disease."

Researchers say the next step is to identify the particular genes that interact with each of the three lifestyle factors to increase the risk of high blood pressure.

SOURCES:

Franceschini, N. Circulation: Cardiovascular Genetics, July 2009; vol 2.

News release, American Heart Association.

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