March 2 (UPI) -- Researchers have identified 83 new genetic variations that affect blood pressure by looking at cigarette smoking behavior, according to a new study.
Previous research has shown that smoking impacts blood pressure, and researchers hope their findings will lead to the development of individually-targeted treatments to manage hypertension. The National Heart, Lung and Blood Institute, which is part of the National Institutes of Health, funded the new study, which was published in the March 1 issue of The American Journal of Human Genetics.
"We know that blood pressure is influenced by both genetic and lifestyle factors, such as smoking cigarettes," Dr. Yun J. Sung, an associate professor of biostatistics at the Washington University School of Medicine, St. Louis, said in an NIH press release.
About 75 million American adults have high blood pressure -- often referred to as the "silent killer" -- according to the Centers for Disease Control and Prevention. The condition puts people at greater risk for heart disease and stroke.
Previous genetic studies have identified genes and genetic regions strongly associated with blood pressure, but they didn't explore the relationship between genes and environmental factors.
Researchers tested different points of the genome of more than 610,000 people in search of interactions between cigarette smoking and blood pressure.
Using a technique known as gene-environment interaction analysis, researchers confirmed 56 known genetic regions and 83 novel regions linked to blood pressure. The effects of some genes on blood pressure only show up under specific environmental influencers, such as cigarette smoking. So, those genes' connection to hypertension could have gone unnoticed because of nonsmoking.
Ten newly discovered genes had as much as eight times the impact on smokers' blood pressure than those of nonsmokers.
Sung said a large study sample size was key to finding the genes.
"Most of the genetic regions previously linked to blood pressure had been identified through individuals of European ancestry. In our study, several novel regions were identified through African ancestry analysis, highlighting the importance of pursuing genetic studies in diverse populations," said Sung.
In the study, 129,913 individuals came from four ancestries: European, African, Asian and Hispanic.
Researchers in the Gene-Lifestyle Interactions Working Group of the Cohorts for Heart and Aging Research in Genomic Epidemiology, or CHARGE, Consortium assisted in the analysis of the large samples.
The researchers said they plan to use even larger sample sizes to investigate the influence of other lifestyle factors on blood pressure and lipids.