Getting enough sleep is important, but new research shows that sticking to a regular sleep schedule may be even more crucial for heart health.
A study published in the Journal of Epidemiology & Community Health found that people with irregular sleep-wake cycles are at a higher risk of major cardiovascular events, such as heart attacks and strokes, even if they sleep the recommended number of hours each night.
What is irregular sleep?
Irregular sleep means going to bed and waking up at different times every day.
Unlike most studies that focus on sleep duration, this research looked at how inconsistent sleep patterns affect health.
The study included 72,269 participants aged 40 to 79 from the UK Biobank, none of whom had a history of major heart problems. Participants wore activity trackers for a week to monitor their sleep habits. Based on the data, researchers calculated a Sleep Regularity Index (SRI) score:
- Regular sleepers: SRI score above 87
- Irregular sleepers: SRI score below 72
- Moderately irregular sleepers: Scores in between
The participants were then monitored for eight years to track incidents of cardiovascular problems, including heart attacks, strokes, and heart failure.
The study found that irregular sleepers were 26% more likely to have a major cardiovascular event compared to regular sleepers. Moderately irregular sleepers had an 8% higher risk.
Interestingly, even if irregular sleepers got the recommended amount of sleep—7 to 9 hours per night for adults under 65 and 7 to 8 hours for those 65 and older—they were still at higher risk for heart problems.
Regular sleepers were more likely to meet the recommended sleep duration (61%) than irregular sleepers (48%).
Why does sleep regularity matter?
The risk of heart problems decreased almost linearly as sleep regularity improved, meaning the more consistent your sleep schedule, the lower your risk. The researchers suggest that irregular sleep patterns may disrupt the body’s natural rhythms, potentially affecting heart health.
While the study had a large sample size, it’s important to note that it was observational, meaning it cannot prove that irregular sleep directly causes heart problems. Other factors, such as assessing sleep patterns over only one week and not accounting for naps, may also have influenced the results.
Key takeaways
This research highlights the importance of maintaining a consistent sleep schedule, not just focusing on sleep duration.
“Our findings suggest that sleep regularity may be more important than simply getting enough hours of sleep in reducing the risk of major heart problems,” the researchers said.
To improve heart health, public health guidelines and clinical advice should include recommendations for regular sleep patterns, alongside other lifestyle changes like a balanced diet and exercise.
If you care about heart health, please read studies about the best time to take vitamins to prevent heart disease, and scientists find how COVID-19 damages the heart.
For more information about heart health, please see recent studies about Aspirin linked to higher risk of heart failure, and results showing Blackcurrants could improve artery functions, blood pressure in older people.
