Sleep apnoea greatly increases risk of stroke, US scientists find
Snoring loudly and feeling tired even after a full night’s sleep could leave people at an increased risk of a stroke, a study has shown.
Hundreds of millions of people globally have sleep apnoea, a disorder with symptoms including stopping and starting breathing, making snorting noises, waking up a lot and loud snoring. Many have the condition but are undiagnosed.
The condition is already known to heighten the risk of serious health problems such as high blood pressure, type 2 diabetes and depression. Now US researchers have uncovered more evidence about its impact on the heart.
Sleep apnoea significantly raises the risk of atrial fibrillation and stroke, they say.
The findings are being discussed by doctors this weekend at the annual meeting of the European Society of Cardiology, the world’s largest heart conference.
A pair of studies involving experts from Stanford University looked at about 1.7 million people aged 20 to 50 over a decade. Those with sleep apnoea were five times more likely to develop atrial fibrillation and 60% more likely to experience a stroke later in life, they found.
Sanjiv Narayan, a professor of cardiovascular medicine at Stanford and the study’s author, said: “We found a 60% increased risk of having a stroke if you have sleep apnoea.“Sleep apnoea is really common but we sort of ignore it because we think it’s trivial or just a little bit of a nuisance. Until now no one’s really shown the magnitude of the size of the risk.
“That’s what really surprised us. And also this is in the relatively young. People that if they had a stroke it would devastate young families. It could take them away from the workplace. It would destroy their lives for the next 40 years.”
Sleep apnoea happens if your airways become too narrow while you sleep. This stops you breathing properly. Its causes are not always clear, but it has been linked to factors such as obesity, having a large neck, smoking and drinking alcohol and sleeping on your back.
Atrial fibrillation is a heart condition that causes an irregular and often abnormally fast heart rate.
A normal heart rate should be regular and between 60 and 100 beats a minute when you are resting.
Narayan said: “When you are unable
to breathe it raises the pressure in the lungs until you ultimately wake up gasping for breath.
“That puts a pressure load on the heart, which causes stretch in the heart chambers, and that could cause the atrial fibrillation. Another theory could be that the oxygen levels in the blood fall for tens of seconds and that could put stress on the heart.”
Sleep apnoea can sometimes be treated by making lifestyle changes such as losing weight, giving up smoking and reducing how much alcohol you drink. But many people need to use a device called a Cpap machine.