New research suggests that irregular sleep patterns may increase the risk of heart attack, stroke, and other cardiovascular events, even for individuals who get the recommended amount of sleep, CNN reports
The study, published this week, sheds light on how inconsistent sleep schedules—such as varying bedtimes and wake-up times—can be detrimental to heart health.
While much of the prior research on sleep has focused on the duration of sleep, this study specifically examined how variations in sleep timing could affect cardiovascular risk. Researchers tracked the sleep habits of 72,269 participants aged 40 to 79, who had no prior history of major heart-related issues. Over a period of eight years, the team monitored incidents of cardiovascular death, heart attack, stroke, and heart failure.
The results revealed that individuals with irregular sleep schedules had a 26% higher risk of experiencing a major cardiovascular event compared to those with more consistent sleep patterns. This risk remained even among participants who achieved the recommended 7 to 9 hours of sleep per night.
The researchers used a metric known as the Sleep Regularity Index (SRI) to assess how regular participants’ sleep habits were. A higher SRI score indicated a more regular sleep cycle, while lower scores indicated more variation in sleep times. Interestingly, those with more regular sleep patterns were more likely to meet the recommended sleep duration, with 61% of regular sleepers achieving the ideal amount of rest compared to 48% of irregular sleepers.
Lead author Jean Pierre Chaput, a professor of pediatrics at the University of Ottawa, emphasized that the findings suggest sleep regularity might be even more important than sleep duration when it comes to heart health. He noted that growing evidence links sleep irregularity with higher mortality risk.
“Our results suggest that sleep regularity may be more relevant than sufficient sleep duration,” Chaput stated.
He advised individuals to aim for seven to nine hours of consistent, restorative sleep each night, as disrupted sleep patterns can contribute to high blood pressure, a significant risk factor for cardiovascular disease.
Chaput also recommended keeping bedtimes and wake-up times within 30 to 60 minutes of each other each day to support the body’s natural circadian rhythm. Small variations in sleep times are acceptable, but consistency can improve sleep quality, cognitive function, and reduce the risk of health problems like heart disease and diabetes.
Chaput cautioned against relying on weekend sleep catch-ups to compensate for poor sleep during the workweek. While extra sleep on weekends may provide temporary relief, it does not negate the long-term effects of inconsistent sleep during the week.
While the study highlights an important connection between sleep patterns and heart health, some experts caution against drawing definitive conclusions about causality. Naveed Sattar, a cardiometabolic medicine professor at the University of Glasgow, pointed out that other factors, such as late-night alcohol consumption, could also contribute to poor health outcomes and irregular sleep.
Despite this, researchers continue to stress the importance of healthy sleep habits as a key factor in preventing heart disease and other chronic conditions.
The study, published in the Journal of Epidemiology & Community Health, calls for further research to explore the long-term impacts of sleep irregularity and its role in cardiovascular health.
