Irregular bedtime may be an early warning sign of stroke or heart failure

New research has linked everyday sleep habits, particularly on weekends, with potentially serious heart conditions

Having a long lie-in or skipping going to bed may also have a negative effect(Image: Getty)

A person’s sleep routine could be a warning sign for heart problems, including stroke. New research suggests that regularly changing when you go to bed, such as staying up later at weekends, may be harmful to health.

Specialists studying the relationship between sleep and heart health also found that large changes in sleep length, such as long lie-ins or missing bedtime altogether, may have a negative impact.

The study has not yet been peer-reviewed and is due to be presented at the American Heart Association’s Scientific Sessions in Chicago.

Researchers examined more than one million nights of sleep and concluded that keeping a steady sleep schedule may be an important way to help protect the heart.

Lead researcher Dr Nguyen Minh Tuan Viet, a neuroscientist and postdoctoral research fellow at Boston Children’s Hospital and Harvard Medical School in the US, said: “While we often focus on getting a full eight hours of sleep every night, having a regular sleep schedule – consistent bedtimes, wake times, and sleep duration from night to night – is a practical, actionable step anyone can take that may help protect their heart and blood vessels.”

The team analysed sleep data from more than 10,000 adults who wore an activity tracker as part of the National Institutes of Health’s All of Us research programme.

They assessed sleep quantity, meaning total hours slept each night; sleep quality, or how much time was spent in light, deep and REM sleep; and how long people remained awake after first falling asleep.

Researchers also looked at how much sleep duration, bedtime and wake-up time changed from night to night over roughly six months, along with the usual times participants fell asleep and woke up. Natural sleep preference, such as being a night owl or an early bird, was also included.

The number of complete sleep cycles finished each night — measured from the end of one REM period to the end of the next, including the light and deep stages in between — was also reviewed.

The findings showed that changes in sleep timing from one night to the next over about a six-month period were associated with a 20% to 23% higher risk of serious problems, including heart attack, stroke and heart failure.

For every 29-minute increase in night-to-night variation in sleep length, the risk also rose. That included a 29% higher risk of disease of the heart muscle, which prevents the heart from pumping enough blood around the body, and a 20% higher risk of heart failure.

A greater number of complete sleep cycles each night was linked to a 28% lower risk of atrial arrhythmia, a common type of irregular heartbeat. By contrast, an unusually long sleep cycle was associated with a 55% higher risk of heart attack or stroke.

Dr Viet said: “Sleep irregularity is often due to weekends – we get to sleep a little bit later on a Friday night; or people have shift work.

“This may not be good for your heart health. Sometimes the quality of sleep is something we cannot control.

“But the regularity, consistent bedtimes throughout the week and waking up at the same time every morning, is something some people can control.”

Participants in the study had an average age of 53, and around seven in 10 were women.

None had heart or metabolic disease at the start of the study. Sleep was monitored for about six months, and participants were then followed for nearly four years to see whether they developed heart problems.