It’s not just a lack of enough sleep that affects a person’s health, a new study suggests. Having irregular sleep patterns can contribute to the risk of cardiovascular problems, according to recent evidence.
Scientists already know that sleep is of the utmost importance to health. Research has shown that without enough sleep, almost every aspect of health is affected, from cognitive functioning to immunity.
But even people who sleep for a good number of hours each night may face greater risks to their health if their sleep is irregular, that is, if the hours they sleep vary greatly from night to night, or if their bedtime and time to wake up changes a lot
A new study by researchers at Brigham and Women’s Hospital in Boston, MA, found that people with highly irregular sleep patterns are more likely to experience cardiovascular events than those with more regular sleep. The study authors report their findings in the Journal of the American College of Cardiology, stressing the importance of good sleep hygiene.
“When we talk about interventions to prevent heart attacks and strokes, we focus on diet and exercise”,says lead author Tianyi Huang.
He continues: “Even when we talk about sleeping, we tend to focus on duration, how many hours a person sleeps each night, but not on the irregularity of sleep and the impact of lying down at different times, or sleeping different amounts from night to night. night.”
“Our study indicates that healthy sleep is not just about quantity, but also variability, and that this can have a major effect on heart health”.
More than twofold increase in risk
The researchers analyzed data from 1,992 participants older than 60 and 70 years with no cardiovascular problems at the start of the study. Participants were of various ethnicities, including African American and Chinese American, and all data came from the Multi-Ethnic Study of Atherosclerosis. The team was able to map the sleep patterns of the participants, as each agreed to wear an actigraphy unit, an activity-tracking monitor worn on the wrist, over a 7-day period.
This allowed the researchers to obtain information about the participants’ bedtime, sleep duration, and wake-up time. The researchers also had access to health monitoring information, which covers an average period of 4.9 years. During that period, a total of 111 participants experienced different cardiovascular events, such as heart attacks and strokes.
The research team noted that participants who exhibited the most irregular sleep patterns – those with a 2-hour or more difference in sleep duration each night – had a more than twofold increased risk of cardiovascular problems, compared to those 1 hour or less apart. in the duration of sleep. Even after adjusting for other risk factors for cardiovascular problems, the researchers found that the association between irregular sleep patterns and cardiovascular events remained significant.
“Although we also observed that participants with irregular sleep tended to have poorer cardiometabolic risk profiles at baseline, adjusting for established risk factors [cardiovascular disease] (eg, blood pressure, lipids, diabetes, etc.) it only explained a small portion of the associations between sleep irregularity and [cardiovascular disease] risk”, they write in their study paper.
Still, the current research was not without limitations. The researchers explain that the cohort whose data they had access to was relatively small, and the follow-up time was not long enough to make the link between sleep patterns and cardiovascular risk unquestionable.
However, the team notes that if other studies confirm their findings, they will be interested in finding out whether modifying a person’s sleep patterns could reduce their risk of heart and vascular problems.
“Sleep regularity is a modifiable behavior. In the future, we would like to explore whether changing sleep patterns by going to bed consistently each night can reduce a person’s risk of future cardiovascular events”, says Huang.