The study, published in the journal of the European Society of Cardiology, used data from more than 88,000 participants in the British Biobank. Scientists focused on information about cardiovascular diseases in volunteers, as well as the time when they usually went to bed, which was recorded by special gadgets on the wrist (sliptracker).
The participants were followed up for 5.7 years, with 3172 cases of cardiovascular disease recorded in the cohort during this period. According to scientists, the lowest risk of developing such pathologies was in people who went to bed no earlier than 22:00 and no later than 23:00. Notably, the association between cardiovascular risk and bedtime was stronger in women.
The study authors also reported that a later time to fall asleep is associated with an increased risk of congestive heart failure. The most “dangerous” was the time after midnight – the later a person goes to bed, the higher his risk of developing cardiovascular diseases.
“Our results also showed the benefits of collecting sleep time data using special devices with accelerometric functions, which can serve as indicators of cardiovascular risk,” the scientists said.
According to the National Sleep Foundation, an adult needs at least 7-9 hours of sleep a night. Scientists found that people who slept an average of 7 hours a day had the lowest risk of heart disease. Those who slept 6 or 8 hours each had an excess heart age of 4.5 years, and those who slept an average of 5 hours or less – this figure was 5.1 years.