THE ESSENTIAL
- An irregular sleep-wake cycle is associated with an increased risk of major cardiovascular events, according to a new study.
- Irregular sleepers were 26% more likely to have a stroke or heart attack.
- Having the recommended quota of hours of sleep did not offset the impact of the irregular sleep/wake cycle.
Going to bed at set times in order to get quality sleep is one of the first recommendations of health professionals. Not following this advice would not only result in greater fatigue.
According to a study published in the journal Journal of Epidemiology & Community Healthan irregular sleep-wake cycle is associated with an increased risk of cardiovascular disorders (heart attack, stroke), even if the person sleeps well for the recommended 7 to 9 hours.
Sleep: irregular schedules increase cardiovascular disorders
Researchers discovered the link between irregular sleep and increased risk of cardiovascular incidents by reviewing the records of 72,269 people aged 40 to 79 who participated in the British Biobank study. These volunteers wore an activity tracker for seven days to record their sleep. The data collected was used, among other things, to calculate their sleep regularity index (SRI Sleep Regularity Index) score. The team also noted deaths from cardiovascular disease, heart attacks, heart failure and stroke over the next 8 years.
By bringing together and analyzing all the information collected, the scientists discovered that sleepers who went to bed and woke up at different times were 26% more likely to have a major cardiovascular event than those who slept at fixed times. Those who had moderately irregular sleep had an 8% increased risk of stroke or heart attack.
“More detailed analysis of the data showed that the relationship between decreasing SRI score and higher risk of events was almost linear, with a stronger reduction in risk at higher (better) SRI scores.“, specify the authors in their press release.
Stroke, heart attack: a good amount of sleep does not reduce the risks
Despite their changing bedtimes and wake-up times, nearly 5 in 10 irregular sleepers achieved the recommended amount of nighttime sleep. That is to say between 7 and 8 hours for people aged 18 to 64 and between 7 and 8 hours for people aged 65 and over.
However, “getting enough sleep” does not seem to have a protective effect on their cardiovascular system. “When the impact of increasing the recommended sleep quota was taken into account, the risk of a major cardiovascular event was not offset in affected irregular sleepers. However, it was offset in moderately irregular sleepers.”
For the researchers, their study shows that it would be more interesting to take into account the regularity of sleep rather than its duration to assess and modulate the risks of cardiovascular events in patients. “The results of this study suggest that more attention should be paid to sleep regularity in public health guidelines and clinical practice because of its potential role in cardiovascular health”conclude the experts.
