Heart disease and stroke link to poor sleep

25^th May 2017 – Many people at risk of heart disease and diabetes are at a higher risk of dying from heart disease or stroke if they get less than 6 hours sleep a night, says a US study.

Researchers writing in the Journal of the American Heart Association say the risk could be around double that of those who don't have the same risk factors – known as metabolic syndrome.

Sleep lab tests

Sleep deprivation has previously been linked to many health conditions including high blood pressure, stroke and heart disease. But the researchers say their study is unique because it's the first to measure sleep duration in the laboratory rather than rely on self-reporting by patients.

The study, led by a team from the Hershey Medical Center in Hershey, Pennsylvania, examined data from 1,344 men and women with an average age of 49. All the participants spent a night in a sleep laboratory as part of a health study.

The participants were assessed for metabolic syndrome. Risk factors included being obese with a body mass index ( BMI) of more than 30, high cholesterol, high blood pressure and elevated levels of fasting blood sugar and blood fats known as triglycerides.

The results showed that 39.2% of those taking part had at least 3 of these factors that increased their risk of heart disease.

All of the participants were monitored for an average of 16.6 years, during which time 22% of them died.

Death risk

The researchers found that compared to people without the same cluster of risk factors, those with metabolic syndrome who slept for more than 6 hours in the laboratory had a 49% higher risk of dying from heart disease or a stroke than those who did not have the risk factors.

However, those who slept less than 6 hours were slightly more than twice as likely to die of heart disease and stroke.

Also, those who slept least were more likely to die for any reason compared to those without metabolic syndrome, the results show.

The researchers say the accuracy of their findings are boosted because they took into account other factors such as whether individuals had sleep apnoea – a condition in which breathing stops during sleep and which is known to increase the risk of developing heart disease.

The authors say they can't prove cause and effect because they carried out an observational study in which the findings were outside their control. Also, they could only draw on information from one day of sleep laboratory results.

They say that future research should concentrate on whether longer sleep patterns could help people with metabolic syndrome.

Cardiovascular health

Commenting on the findings by email, Professor Jeremy Pearson, associate medical director at the British Heart Foundation, says: "This strengthens the evidence that a lack of sleep may increase your risk of cardiovascular disease, and that we should all try to find ways of making sure we get a proper night's rest.

"There are simple things you can do to help, such as being more active during the day, but if you’re struggling to sleep then speak to your GP."