Health · Medical Research · 4 hrs ago
Irregular sleep schedules linked to higher risk of heart problems
A study led by researchers at Harvard and Boston Children’s Hospital found that irregular sleep schedules were linked to higher cardiovascular risk.
It tracked 10,362 adults who had no heart or metabolic disease when the study began.
Participants wore devices for about six months to record when and how long they slept, and researchers followed their health for a median of 3.7 years.
People with greater night-to-night changes in sleep timing had a 20% to 23% higher risk of heart attack, stroke or heart failure.
More variation in sleep duration was also linked to increased cardiovascular risk, while completing more sleep cycles was associated with a lower risk of atrial fibrillation.
The findings describe an association, not proof that irregular sleep causes heart problems, and do not mean one short night is dangerous on its own.
The study used data from the US National Institutes of Health’s All of Us programme and was presented at the American Heart Association’s 2026 Scientific Sessions.
Irregular bedtimes and wake times were associated with a 20% to 23% higher risk of heart attack, stroke or heart failure.
The study followed 10,362 adults who had no heart or metabolic disease at the start.
Participants’ sleep was recorded for about six months, and their health was followed for a median of 3.7 years.
The analysis found associations, not proof that irregular sleep directly causes cardiovascular problems.
The research was presented at the American Heart Association’s 2026 Scientific Sessions.
- Who
- Researchers led by Nguyen Minh Tuan Viet studied 10,362 adults.
- What
- The study linked irregular sleep schedules with a higher risk of cardiovascular events.
- When
- Sleep was recorded for about six months, followed by a median of 3.7 years of health follow-up. The research was presented at the AHA’s 2026 Scientific Sessions.
- Where
- The participants were part of the US National Institutes of Health’s All of Us programme.
- Why
- The researchers examined whether sleep timing, duration and cycles were associated with cardiovascular health; the reasons for the associations were not established.
This story does not have two clearly opposing sides.
Participants wore devices that recorded their bedtimes, wake times, sleep duration and sleep phases.
Researchers followed participants to identify heart and cerebrovascular problems.
The research was presented at the American Heart Association’s Scientific Sessions.
- Participants
- 10,362 adults
- Sleep data
- More than one million nights
- Bedtime and wake-time variation
- Associated with a 20% to 23% higher risk of heart attack, stroke or heart failure
- Sleep-duration variation
- Each 29-minute increase was associated with a 24% higher risk of a combined cardiovascular outcome
- Participants’ average age
- 53 years
- Women in the sample
- 69%