People with certain blood types are more likely to suffer a heart attack during periods of pollution, warns new research.
The study shows that people who have A, B, or AB blood types have an ‘elevated risk’, compared to those with the O blood type.
Scientists have known for some time that pollution is linked to a raised chance of a heart attack but it is the first time that the risk has also been linked to blood type.
A study of 14 years of patient data discovered that the risk of a heart attack or chest pain doubled for people of type A, B, or AB blood when pollution hits high levels.
In comparison, the risk rose by 40 percent for those with type O, according to researchers from the Intermountain Medical Center Heart Institute in Utah, US.
Risk of a heart attack or chest pain during periods of pollution doubled for people of type A, B, or AB blood (stock photo)
Study lead investigator Doctor Benjamin Horne said: ‘We wondered, if someone has a specific variation in this ABO gene, are they more or less likely to experience a heart attack in times of higher pollution?
‘The primary mutation we studied differentiates between O blood types and non-O, which includes positive and negative A, B, and AB blood types.
‘The one that’s been found in genetic studies to be lower risk is O. The other three were higher risk.’
Not something to panic over
Previous studies have also shown links between small-particulate PM2.5 pollution and heart attacks, admission to the hospital with unstable chest pain, heart failure, and atrial fibrillation, also known as an irregular heartbeat.
The new study was designed to build on and tie together those findings and test the influence of one variation, the impact of an individual’s blood type.
Dozens of genes have been shown in large international studies to predict the onset of coronary artery disease in people who are free of the disease.
But the vast majority of people won’t have a heart attack unless they already have coronary artery disease. Nor is a heart attack a certainty even with heart disease.
Dr Horne said: ‘You have to have other characteristics for coronary disease to progress to a heart attack.
‘The association between heart attacks and pollution in patients with non-O blood isn’t something to panic over, but it is something to be aware of.’
He said the researchers had already identified a level of pollution at which the increased risk occurred for people with non-O blood types, and that threshold is 25 micrograms of pollution per cubic metre.
‘Two years ago we published findings that showed once you go above that, each additional 10 micrograms of pollution per cubic metre of air provided substantially higher risks,’ he added.
‘At levels higher than 25 micrograms per cubic metre of pollution, the increase in risk is linear, while below that level there’s little if any difference in risk.’
AIR POLLUTION LINKED TO WEAKER BONES
Air pollution could cause brittle bone disease, according to new research.
A study by Columbia University’s Mailman School of Public Health that analyzed data on more than nine million people enrolled in Medicare in the Northeastern US is the first to find a link between traffic fumes and fractures caused by osteoporosis.
In the US, 9 million men and have osteoporosis, leading to a bone fracture every three seconds, according to the International Osteoporosis Foundation.
The study linked pollution exposure to low levels of parathyroid hormone, which regulates calcium production, leading to weaker bones and more hospitalizations for fractures.
Smog-filled towns and cities have been linked to an increased risk of stroke, heart disease, lung cancer, acute respiratory diseases such as asthma and even dementia.
But this study is the first to link air pollution to the degradation of the weakened bones of 200 million people around the world.
The clinical data used for the study came from Intermountain Healthcare patients seen between 1993 and 2007.
Study co-author Professor Arden Pope, of Brigham Young University, provided the air pollution data.
He said, during a winter inversion, the PM2.5 pollution level can occasionally reach as high as 100 micrograms per cubic metre, but 50 to 60 is more typical.
The researchers found that people with type O blood also have higher risk of heart attack or unstable chest pain in times of high air pollution.
But Dr Horne said their level of risk is much smaller, at 10 per cent instead of the non-O blood type’s 25 per cent per 10 additional micrograms per cubic metre,
He said at the 65 micrograms per cubic metre pollution level, a person with type O blood faces risk that’s 40 per cent higher than if the air wasn’t polluted.
Dr Horne added: ‘In the information we provide to our patients about pollution, we try to stress that they can do something about it to reduce their risks: stay indoors out of pollution. Exercise indoors. And make sure they’re compliant with taking their heart medication to reduce their risk.’
The findings are due to be presented at the American Heart Association Scientific Sessions in Anaheim, California.