Four hours of TV a day raises sleep apnoea risk by 78%, study suggests

·4 min read
Person having feet up under blanket and watching TV
Too much TV time raises the risk of obesity, a known cause of sleep apnoea. (Stock, Getty Images)

Many people look forward to a night in front of the TV after a stressful day at work.

Bingeing on boxsets may not be a harmless indulgence, however, with Harvard scientists warning too much sofa time may raise a person's sleep apnoea risk.

The team analysed the lifestyle habits of more than 137,000 people over 10 to 18 years.

Results reveal those who watched TV for at least 28 hours a week – equivalent to four hours a day – were 78% more likely to develop sleep apnoea than those who spent less than four hours a week in front of the box.

Excessive TV watching was linked to an overweight body mass index or large waist circumference, with obesity a known risk factor for sleep apnoea.

Read more: 'Sometimes' watching TV in middle-age speeds up cognitive decline

Also known as obstructive sleep apnoea (OSA), the condition occurs when a person's breathing stops and starts while they slumber, reducing oxygen levels in their blood. This can cause snoring, insomnia and fatigue the next day.

Left untreated, sleep apnoea has been linked to high blood pressure, heart disease and type 2 diabetes.

Senior woman using cpap machine to stop choking and snoring from obstructive sleep apnea with bokeh and morning light background.
In severe cases, OSA can be treated via a so-called CPAP machine, which gently pumps air into a mask worn over the mouth or nose while a patient sleeps. (Posed by a model, Getty Images)

"The difference in OSA risk between sedentary work and time spent sitting watching TV could be explained by other behaviours that are related to those activities," said lead author Dr Tianyi Huang. 

"For example, snacking and drinking sugary drinks is more likely to go along with watching TV compared with being sedentary at work or elsewhere, such as sitting during travelling. 

Read more: Exercise may counteract health harms of too little sleep

"This could lead to additional weight gain, which we know to be a risk factor OSA."

Around 1.5 million adults are thought to have sleep apnoea in the UK, of whom up to 85% are undiagnosed.

Old age, a family history of OSA and having a large neck have been linked to the condition. Smoking, drinking alcohol, having large tonsils and sleeping on your back may also be to blame.

Although not recognised by the NHS, a sedentary lifestyle could trigger sleep apnoea if it causes weight gain, inflammation or fluid retention, according to the Harvard scientists.

Read more: Prescribed sleep pills ineffective long term

To learn more, the team analysed participants of the Health Professionals Follow-up and Nurses' Health studies, none of whom had sleep apnoea at the start of the research.

The participants then completed questionnaires on their exercise and TV watching habits every two to four years.

Up to 18 years later, more than 8,700 of the participants had been diagnosed with sleep apnoea.

As well as too much TV time, failing to exercise was linked to an increased risk of the condition.

The participants whose activity level was equivalent to three hours of running a week were 54% less likely to develop apnoea as those who only walked for two hours at a normal pace every seven days, as published in the European Respiratory Journal.

Those with a sedentary job were also 49% more likely to develop apnoea as those with a more active lifestyle. Exercising in your spare time could counteract this risk, however.

People with "physical constraints" could lower their risk by spending more time standing or doing gentle activities.

"Importantly, we saw any additional increase in physical activity, and/or a reduction in sedentary hours, could have benefits that reduce the risk of developing OSA," said Dr Huang.

Watch: Sleep apnoea linked to spine fractures in women

The participants self-reported their health data, which may affect the accuracy of the results, according to the scientists. Future research could be based on wearable health monitors, they added.

Nevertheless, Professor Anita Simonds – from the Royal Brompton Hospital in London – said: "This study adds to the evidence on the importance of maintaining an active lifestyle on preventing lung disease.

"It is encouraging that even a small increase in physical activity or reduction in sedentary hours could reap potential benefits.

"OSA is a common and pervasive disorder that can have a serious impact on the quality of people's lives. 

"Although OSA can be managed with modern treatments, only a minority of studies focus on prevention. 

"Health professionals should prioritise prevention and support people who are at-risk of developing OSA to be more active before it is too late."

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