Going to bed at right time could mean ‘difference between life and death’

By Tom Campbell via SWNS

Going to bed at the 'golden hour' of 10 pm to 11 pm could mean the difference between life and death, scientists have found.

Tucking up between those times may lower the risk of developing heart disease compared to earlier or later bedtimes, according to a new study.

Heart and blood conditions are responsible for around a quarter of all deaths in the UK, more than 160,000 per year.

Previous studies have examined whether the odds of developing a heart condition are improved by sleep duration, but rarely people’s bedtime.

Now, researchers at the University of Exeter have found making sure people get to sleep at the right time could help reduce the risk of heart disease for millions of people.

Dr. David Plans said: “The body has a 24-hour internal clock, called circadian rhythm, that helps regulate physical and mental functioning.

“While we cannot conclude causation from our study, the results suggest that early or late bedtimes may be more likely to disrupt the body clock, with adverse consequences for cardiovascular health.”

Data on 88,026 people aged 43 to 79 who had been recruited between 2006 and 2010 was analyzed by the researchers.

Participants were asked to wear an accelerometer on their wrist for seven days so the researchers could monitor their sleep and wake-up times.

They also complete assessments and questionnaires about their demographic, health and lifestyle choices.

A follow-up diagnosis of cardiovascular diseases, including heart attack, heart failure, chronic ischaemic heart disease, stroke and transient ischaemic attack, was then carried out.

People who went to bed after midnight had a 25 percent higher chance of developing one of these conditions compared to those who hit the hay between 10:00 pm to 10:59 pm, the researchers found.

Likewise, getting to bed before 10:00 pm raised the risk of cardiovascular disease by 24 percent and by 12 percent for those who nodded off between 11:00 pm and 11:59 pm.

Plans said: “Our study indicates that the optimum time to go to sleep is at a specific point in the body’s 24-hour cycle and deviations may be detrimental to health.

“The riskiest time was after midnight, potentially because it may reduce the likelihood of seeing morning light, which resets the body clock.”

The link between bedtime and risk of heart disease was strongest among women while only those before 10:00 pm remained significant for men, the researchers found after conducting further analysis by sex.

Plans said: “It may be that there is a sex difference in how the endocrine system responds to a disruption in circadian rhythm.

“Alternatively, the older age of study participants could be a confounding factor since women’s cardiovascular risk increases post-menopause – meaning there may be no difference in the strength of the association between women and men.”

While further research is needed, targeting people’s bedtimes could reduce the risk of heart disease for millions of people, if their findings are confirmed.

Plans said: “While the findings do not show causality, sleep timing has emerged as a potential cardiac risk factor – independent of other risk factors and sleep characteristics.

“If our findings are confirmed in other studies, sleep timing and basic sleep hygiene could be a low-cost public health target for lowering the risk of heart disease.”

The findings were published in the journal European Heart Journal – Digital Health.