A new 10-year study suggests that bedtime consistency may matter as much as sleep duration for heart health after age 40. Published in BMC Cardiovascular Disorders, the research followed 3,231 adults, all age 46 at the start, and tracked their sleep patterns alongside medical outcomes over a decade.
What the researchers observed
By the end of the study period, 128 participants had experienced a major cardiovascular event, including unstable angina, stroke, heart failure, or a cardiac-related death. After adjusting for factors such as body mass index and cholesterol, the clearest pattern was that people with highly variable bedtimes faced greater risk.
The risk of heart problems was especially elevated among those whose bedtime kept shifting and who also slept less than eight hours a night. In contrast, changes in wake-up time did not appear to have the same effect.
Lead author Laura Nauha of the University of Oulu said the findings point to bedtime regularity as a meaningful marker of everyday rhythm. Specialists in sleep medicine and cardiology note that the body's circadian system helps regulate hormones, blood pressure, and heart function, making stable sleep timing an important part of recovery.
How to build a steadier sleep rhythm
Experts recommend a simple routine: begin winding down about an hour before bed, reduce screen use, avoid caffeine and intense activity late in the evening, and keep the bedroom calm and dark. If sleep does not come quickly, getting up briefly and returning only when drowsy can help the brain reconnect the bed with rest.
As sleep science continues to connect daily habits with long-term wellness, consistent bedtimes may become a practical tool for protecting cardiovascular health in the years ahead.