Heart disease is the leading killer of Americans. But by going to bed between the hours of 10 p.m. and 11 p.m., you may lower your risk of developing this condition, according to a recent study published in European Heart Journal – Digital Health.
As part of the study, researchers looked at more than 88,000 individuals between 2006 and 2010. Study participants used a wrist-worn accelerometer to gather data about sleep onset and waking time in participants, whose average age was 61.
Following up an average of 5.7 years later, it was found that 3,172 participants had developed cardiovascular disease. Among those participants, the incidence of heart disease was highest for those who fell asleep at midnight or later and lowest for those who hit the sack from 10 p.m. to 10:59 p.m.
Researchers found that compared with falling asleep between 10 p.m. and 10:59 p.m., there was:
- A 25% greater risk of cardiovascular disease for those going to sleep at midnight or later
- A 12% greater risk with sleep starting between 11 p.m. to 11:59 p.m.
- A 24% greater risk with sleep starting before 10 p.m.
In a press release, study author Dr. David Plans of the University of Exeter says:
“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.”
The researchers note that the association with increased cardiovascular risk was stronger in women. In fact, only sleep onset before 10 p.m. raised the risk significantly for men.
It is unknown why women are at greater risk, Plans said, although he speculated that “it may be that there is a sex difference in how the endocrine system responds to a disruption in circadian rhythm.”
He also said the older age of the study participants could be a factor, as “women’s cardiovascular risk increases post-menopause — meaning there may be no difference in the strength of the association between women and men,” Plans said.
For more on keeping your ticker ticking, check out “Eating This Food Can Sharply Lower Your Risk of Cardiovascular Disease.”