Irregular Sleep Patterns Linked to Higher Risk of Heart Disease and Stroke: Study

Going to bed at different times each night may be putting your heart at risk, even if you are getting enough sleep. New research suggests that inconsistent sleep schedules and changes in sleep duration are associated with a higher risk of heart attack, stroke, heart failure and other cardiovascular complications.

The preliminary findings are scheduled to be presented at the American Heart Association's Scientific Sessions 2026, taking place from November 6 to 9 in Chicago.

Researchers analysed more than one million nights of sleep data from 10,362 adults participating in the US National Institutes of Health's All of Us Research Program.

Participants, whose average age was 53 years, wore activity-tracking devices that recorded sleep duration, timing, quality and sleep cycles.

Sleep patterns were assessed over approximately six months, followed by a median observation period of 3.7 years to identify cardiovascular events.

The findings revealed that greater variations in sleep timing from night to night were associated with a 20% to 23% higher risk of serious cardiovascular events, including heart attacks, strokes and heart failure.

Importantly, every 29-minute increase in nightly variation in sleep duration was associated with a 24% higher risk of the combined cardiovascular outcome.

Researchers also observed a 29% higher risk of heart muscle disease and a 20% higher risk of heart failure with greater sleep-duration variability.

Interestingly, completing more sleep cycles each night was associated with a 28% lower risk of atrial arrhythmia, a type of irregular heartbeat.

However, unusually long sleep cycles were linked to a 55% higher risk of heart attack or stroke.

Researchers suggested that maintaining consistent bedtimes and wake-up times may be an important consideration for cardiovascular health.

Nevertheless, the study was observational and could not establish that irregular sleep directly causes heart disease.

The findings are also preliminary and further research is needed to determine whether improving sleep regularity can independently reduce cardiovascular risk.

REFERENCE: Nguyen Minh Tuan Viet, et al.; Is a consistent sleep schedule important to heart health?; American Heart Association Scientific Sessions 2026, Abstract; https://newsroom.heart.org/news/is-a-consistent-sleep-schedule-important-to-heart-health?preview=a459&preview_mode=True