by Charlene Porter
IIP Staff Writer
3 October 2011
An international research consortium has identified 29 genetic variations that influence blood pressure, providing insight into blood pressure abnormalities that are risk factors for cardiovascular diseases, such as heart attack and stroke. This class of disease is the world’s largest killer, taking more than 17 million lives in 2008, according to the World Health Organization.
Three institutes of the U.S. National Institutes of Health (NIH) funded the work, which involved more than 230 researchers across six continents. To collect their data, the researchers scanned the genomes — that is, the genetic map that determines physical characteristics for living things — of more than 200,000 Europeans and 70,000 people of East Indian, South Asian and African ancestry.
Blood pressure is measured using two numbers. The first, the systolic number, represents the pressure in your blood vessels when your heart beats, and the second, the diastolic number, represents the pressure in your vessels when your heart rests between beats. Blood pressure of 120 over 80 or less is considered normal, while blood pressure of 140 over 90 is a risk for life-threatening heart attacks or stroke.
Among all the diverse study subjects, researchers were looking for variations in genes that might correspond to high systolic or diastolic numbers. Some genes were already suspected to be linked to blood pressure and those suspicions were confirmed. The researchers discovered other genetic variations that were previously unknown, each of which increased the risk of hypertension by a tiny amount. For people who had multiple variants, the effects on blood pressure readings became significant.
The researchers used their findings to develop a risk score for higher-than-normal blood pressure among the test subjects that was applicable across ethnic groups. The risk score was also a good indicator for hypertension complications, such as increased thickness of heart chambers, heart failure, stroke and coronary artery disease.
“This is one of the most important studies of the genetics of high blood pressure to date and a significant step toward finding better therapies for it,” says acting Director Susan B. Shurin of the National Heart, Lung and Blood Institute.
The findings were published in the September issue of the journal Nature, in the same month that the U.N. General Assembly focused on noncommunicable diseases and the need to address them with global cooperation, assistance and collaboration. The cardiovascular diseases associated with high blood pressure are leading causes of death worldwide, in both developed and developing countries.
The U.N. session focused particular attention on the fact that many noncommunicable diseases, including cardiovascular diseases, are preventable. Doctors advise people to make good lifestyle choices to avoid premature death from cardiovascular diseases —eat a balanced diet, don’t smoke, and engage in physical activity on a regular basis.