World's biggest blood pressure genetics study ‘most major advance to date'
DNA samples from more than one million people have helped scientists identify 500 new gene regions influencing blood pressure.
The British-led global study, the biggest of its kind ever conducted, increases the number of known genetic regulators of blood pressure to more than 1,000.
Scientists can now explain almost a third of the heritable risk factors for high blood pressure, or hypertension.
Understanding the genetic causes of high blood pressure could potentially prevent thousands of heart attacks and strokes in the UK each year, according to the British Heart Foundation.
Lead researcher Professor Mark Caulfield, from Queen Mary, University of London, said: “This is the most major advance in blood pressure genetics to date.
“We now know that there are over 1,000 genetic signals which influence our blood pressure. This provides us with many new insights into how our bodies regulate blood pressure, and has revealed several new opportunities for future drug development.
“With this information, we could calculate a person’s genetic risk score for high blood pressure in later life.
“Taking a precision medicine approach, doctors could target early lifestyle interventions to those with a high genetic risk, such as losing weight, reducing alcohol consumption and increasing exercise.”
High blood pressure was responsible for an estimated 7.8 million deaths worldwide in 2015.
More than a quarter of adults in England – around 12.5 million people – are thought to be affected by hypertension.
As many as seven million people in the UK are believed to be living with undiagnosed high blood pressure, unaware of their condition.
For most people, hypertension is defined as a blood pressure reading of 140/90 millimetres of mercury (mmHg) or above.
The first figure refers to systolic blood pressure, which occurs with each pump of the heart. The second, diastolic, reading shows blood pressure during the relaxed phase between heart beats. A lower threshold is set for heart patients.
The new study found that known genetic variants more than tripled the risk of hypertension and increased the likelihood of poor cardiovascular outcomes 1.52 times.
It also identified a number of potential new targets for novel drugs or medicines already developed to treat other conditions. One example of a medicine that potentially could be “repurposed” to treat high blood pressure is the Type 2 diabetes drug canagliflozin.
APOE, a gene that when mutated is strongly associated with hereditary Alzheimer’s disease, is one of the new candidate genes thought to play a role in hypertension.
Genes in the DNA regions highlighted in the study also appear to play key roles in the function of adrenal glands and body fat.
Professor Jeremy Pearson, associate medical director at the British Heart Foundation, said: “Having high blood pressure puts you at significantly higher risk of having a heart attack or stroke.
“Lifestyle factors like not doing enough exercise, being overweight or regularly drinking too much can cause high blood pressure. However, our genes can also play a major role. Unfortunately some people simply draw the genetic short straw and must work harder to stay healthy.
“Knowing which genes cause high blood pressure may help us to spot the people who are at risk, before the damage is done. Those at risk can be treated – either with medication or lifestyle changes – potentially preventing thousands of heart attacks and strokes every year.”
The study, published in the journal Nature Genetics, was funded by the National Institute for Health Research (NIHR), the Medical Research Council (MRC) and the British Heart Foundation.
Professor Chris Whitty, chief scientific adviser for the Department of Health, said: “This large and significant piece of research shows how multiple genetic factors influence blood pressure, providing evidence that is likely to translate into preventative and curative measures for patients in years to come.”