Needing a nap each afternoon could be a sign that you’re at risk of a stroke, a study suggests.
Chinese researchers examined the daytime sleeping habits of 60,000 middle-aged and elderly Britons, tracking their health for 15 years.
Results revealed those who ‘usually’ napped were 12 per cent more likely to develop high blood pressure, compared to those who ‘never’ got 40 winks.
And they were nearly a quarter more likely to suffer a stroke.
However, experts at Xiangya Hospital Central South University in Hunan doubt naps themselves are to blame.
Instead, always needing a ‘siesta’ could simply be a sign of poor sleep quality, which, over the years, has repeatedly been linked to high blood pressure.
And those who don’t sleep enough are more likely to be in poor health, such as being overweight.
Chinese researchers, who examined the daytime sleeping habits of 60,000 middle-aged and elderly Britons, found that those who ‘usually’ nap are a tenth more likely to develop high blood pressure, compared to those who ‘never’ nap
HOW MUCH SLEEP SHOULD I GET?
Most adults need between six and nine hours of sleep every night.
Going to bed and getting up at a similar time each night programmes the brain and internal body clock to get used to a set routine.
But few people manage to stick to strict bedtime patterns.
To get to sleep easier, the NHS advises winding down, such as by taking a bath, reading and avoiding electronic devices.
The health service also recommends keeping the bedroom sleep-friendly by removing TVs and gadgets from the room and keeping it dark and tidy.
For people who struggle to sleep, the NHS says keeping a sleep diary can uncover lifestyle habits or activities that contribute to sleepiness.
Approximately a third of adults in the UK and half of Americans have hypertension, which puts strain on blood vessels, the heart and other organs.
It increases the risk of strokes and heart attacks.
Dozens of studies have found that those who nap – even just for 30 minutes a day — tend to have higher blood pressure by the evening.
However, the truth remains clouded, given some research has found the opposite.
The new study, published in the journal Hypertension, aimed to get to the bottom of the debate.
Dr E Wang and colleagues used information from the UK Biobank – a database containing the health records of half a million Britons aged 40 to 69, who regularly provide detailed information about their lifestyle.
Some 60,686 of those in the Biobank provided information on their napping habits four times between 2006 and 2019.
All of the participants were asked ‘do you have a nap during the day’ and given the options of ‘rarely/never’, ‘sometimes’ or ‘usually’.
The researchers divided the volunteers into one of these three groups, depending on their answer.
Due to the way the question was asked, experts could not calculate the number of days per week and the duration volunteers napped for.
Napping during the day was riskier for younger groups.
Under-60s who usually napped were a fifth more likely to suffer high blood pressure compared to those who never napped.
The risk was half that among the over-60s.
A higher rate of ‘usual’ nappers were men, had lower qualifications and income and were smokers, daily alcohol drinkers and suffered insomnia and snoring, compared to ‘never’ and ‘sometimes’ nappers.
A separate analysis showed that as napping increased by one category – from never to rarely, or rarely to usually– the risk of suffering high blood pressure increased by 40 per cent.
But Dr Michael Grandner, a sleep expert at the University of Arizona, explained that napping itself may not be the cause.
‘Although taking a nap itself is not harmful, many people who take naps may do so because of poor sleep at night,’ he said.
‘Poor sleep at night is associated with poorer health, and naps are not enough to make up for that.’
Dr Grandner added: ‘This study echoes other findings that generally show that taking more naps seems to reflect increased risk for problems with heart health and other issues.’
The study authors called for more research on the links between a healthy sleep pattern, including daytime napping and heart health.
The results excluded anyone who had had a stroke or high blood pressure at the start of the study.
The authors noted that they only looked at daytime napping frequency, not duration of naps, so it is yet to be determined whether the length of a nap affects blood pressure and stroke risks.
And participants were middle-aged or elderly Britons – so the results may not apply to other age and ethnic groups.
The NHS says you should get six to nine hours of sleep every night.
Blood pressure drops during sleep so getting too little means it stays higher for a longer period of time.