Maintaining a consistent sleep schedule may be more important for heart health than previously recognized, according to preliminary research presented at the American Heart Association's Scientific Sessions 2026. The study, which analyzed more than 1 million nights of sleep from over 10,000 adults, found that irregular sleep patterns were associated with a 20% to 23% higher risk of serious cardiovascular events, including heart attack, stroke, and heart failure.
The findings, presented at the Association's premier global exchange of scientific advancements, highlight sleep regularity as a potentially modifiable factor for cardiovascular disease. Lead researcher Nguyen Minh Tuan Viet, M.D., Ph.D., a neuroscientist at Boston Children's Hospital and Harvard Medical School, said, "Having a regular sleep schedule - consistent bedtimes, wake times, and sleep duration from night to night is a practical, actionable step anyone can take that may help protect their heart and blood vessels." The study used data from the National Institutes of Health's "All of Us" Research Program, tracking sleep quantity, quality, regularity, timing, and cycles.
Each 29-minute increase in night-to-night sleep length variability was linked to a 24% higher risk of the combined cardiovascular outcome, including a 29% higher risk of cardiomyopathy and a 20% higher risk of heart failure. More complete sleep cycles per night were associated with a 28% lower risk of atrial arrhythmia, while an unusually long sleep cycle was linked to a 55% higher risk of heart attack or stroke. Viet noted that irregular sleep is often due to weekends or shift work, and that while sleep quality may be beyond control, regularity is something some people can control.
The study's preliminary nature means it has not been peer-reviewed, and experts caution against overinterpretation. Marie-Pierre St-Onge, Ph.D., C.C.S.H., FAHA, a volunteer expert for the American Heart Association who chaired its 2025 scientific statement on Multidimensional Sleep Health: Definitions and Implications for Cardiometabolic Health, said the research adds to the body of evidence on sleep duration but does not establish causality. "This study should prompt scientists to further evaluate links between sleep regularity and cardiovascular disease, so that we can make the same recommendations for regularity that we can for duration," St-Onge said. She added that stable sleep schedules can help achieve better sleep duration.
The analysis included 10,362 adults with an average age of 53, followed for a median of 3.7 years. Limitations include the observational design and the use of wearable devices rather than lab-based sleep monitoring. The findings are considered preliminary until published in a peer-reviewed journal. The research will be featured at Scientific Sessions 2026, and additional details are available in the abstract and the 2026 Online Program Planner. A Spanish news release is also available.
For more information on heart health, visit heart.org and stroke.org. The original release can be viewed at www.newmediawire.com.
