Finnish researchers have found that going to bed at the same time every night can reduce the risk of cardiovascular disease, even if sleep quality or duration is not perfect. In a recent study, researchers tracked the sleep patterns of more than 3,000 middle-aged people in Finland for about 10 years, using wearable devices to measure sleep and other vital indicators. The study found that the regularity of three key factors—bedtime, wake-up time, and sleep midpoint (the time in the middle of the sleep period between falling asleep and waking up)—could predict future cardiac risk. The results showed that people who sleep less than eight hours a day and experience irregularity in their sleep times or fluctuations in their sleep midpoint face a higher risk of serious cardiac events. Conversely, sleeping for more than eight hours may provide a certain level of protection for the heart, regardless of sleep schedule regularity. However, excessive sleep may also be linked to other health problems such as diabetes and metabolic disorders. Researcher Laura Naha, one of the study's authors, noted that these results are the first to separate the effects of irregular bedtime and wake-up times and sleep midpoint, and to study their relationship with heart disease independently. She added that regularity in bedtime, in particular, may be an important factor for heart health as it reflects the stability of the daily life rhythm. The researchers emphasize that the body's circadian rhythm, which operates on a 24-hour cycle, plays a crucial role in regulating hormones and protecting the body from many diseases, including heart disease. The study also suggests that disrupting sleep schedules can throw this balance off and prevent the heart from getting an optimal recovery period at night. Among other factors linking sleep to heart health is chronic stress. A stressful lifestyle, psychological pressure, and fatigue can negatively affect both sleep quality and heart health simultaneously. Interestingly, wake-up time did not show a significant impact on heart health in this study, although other research suggests that the way a person wakes up, such as using annoying alarms, can raise blood pressure and heart rate. These findings confirm that two pre-sleep habits increase the risk of heart attacks: irregular sleep times and fluctuations in the midpoint of the sleep period, even if the duration of sleep is sufficient. This underscores the importance of sleep schedule regularity as a simple yet impactful factor in protecting heart health.
