• Posted August 11, 2023

Bad Sleep Can Harm Your Heart, and Weekend 'Catch-Up' Sleep Won't Help

Poor sleep takes a toll, and catching up on the weekends just won't fix it, researchers report.

A small new study showed that heart rate and blood pressure, important measures of cardiovascular health, worsen as the week goes on when someone sleeps only about five hours a night.

Catching up on sleep over the weekends didn't return those health measures back to normal.

"Only 65% of adults in the U.S. regularly sleep the recommended seven hours per night, and there's a lot of evidence suggesting that this lack of sleep is associated with cardiovascular disease in the long term,"said study co-author Anne-Marie Chang, associate professor of biobehavioral health at Penn State University.

"Our research reveals a potential mechanism for this longitudinal relationship, where enough successive hits to your cardiovascular health while you're young could make your heart more prone to cardiovascular disease in the future," Chang said in a university news release.

The researchers studied 15 healthy men ages 20 to 35 over an 11-day period.

Participants were allowed to sleep up to 10 hours a night over the first three nights, which let researchers note their baseline.

Over the next five nights, the men were limited to five hours sleep per night. That was followed by two recovery nights, when they were allowed to sleep up to 10 hours per night.

Throughout the study, researchers measured participants' resting heart rates and blood pressure every two hours during the day. This made it possible to account for any effects that time of day might have, such as a naturally lower heart rate upon waking.

Participants' heart rates increased nearly one beat per minute (BPM) with each successive day of the study.

The average baseline heart rate was 69 BPM. By the end of the study, it was 78 BPM.

Systolic blood pressure rose each day, from a baseline average of 116 mm Hg to nearly 119.5 mm Hg by the end of the recovery period. Systolic blood pressure, the top number in a blood pressure reading, measures pressure in the arteries when the heart beats. (A reading of 120 or less is considered normal.)

"Both heart rate and systolic blood pressure increased with each successive day and did not return to baseline levels by the end of the recovery period," lead author and Penn State grad student David Reichenberger said in the release. "So, despite having additional opportunity to rest, by the end of the weekend of the study, their cardiovascular systems still had not recovered."

His adviser, Chang, said longer periods may be needed to recover from multiple, consecutive nights of sleep loss.

"Sleep is a biological process, but it's also a behavioral one and one that we often have a lot of control over," she noted.

"Not only does sleep affect our cardiovascular health, but it also affects our weight, our mental health, our ability to focus and our ability to maintain healthy relationships with others, among many other things," Chang said. "As we learn more and more about the importance of sleep, and how it impacts everything in our lives, my hope is that it will become more of a focus for improving one's health."

Study results were recently published in the journal Psychosomatic Medicine.

More information

The U.S. Centers for Disease Control and Prevention has some tips for better sleep.

SOURCE: Penn State University, news release, Aug. 9, 2023