Sleep is crucial to your heart health and your overall health, said a study published in the Journal of the American Heart Association. The study, published on Feb. 15, 2023, found that adults 45 and older who fall asleep at different times and don’t sleep a regular number of hours per night are at higher risk for hardening of the arteries and heart attack or stroke.

The findings came out of a subset of participants in the large Multi-Ethnic Study of Atherosclerosis study. MESA involves more than 6,000 men and women from six communities in the United States and is sponsored by the National Heart, Lung, and Blood Institute of the National Institutes of Health.

If you don't sleep enough on a regular basis, all risk factors for heart disease go up, said U.S. Air Force Col. (Dr.) Travis Batts, the medical director of cardiology at Wilford Hall Ambulatory Surgical Center at Joint Base San Antonio, Texas. “Sleep and heart health go hand in hand.”

Current heart health guidelines recommend adults get seven to nine hours of sleep per night.

“Sleep is the body's time to repair and rejuvenate,” Batts said. “When your body doesn't have time to repair—when it feels like it's at that state of stress—the body tries to fix things in a way that is often harmful to your health.”

Your risk of heart attack goes up about 20% if you are a short sleeper, and about 34% if you are a long sleeper, according to a September 2019 study in the Journal of the American College of Cardiology. The data came from the UK Biobank, a database of 461,000 participants.

“We all recognize that sleep impacts the body in a multitude of ways,” Batts explained. These include “higher risk of cardiometabolic syndrome, obesity, hypertension, and diabetes, not to mention varying degrees of insulin insensitivity. These risks increase our body's propensity for inflammation,” and up the chances for heart disease, he said.

Significance of the Multi-Ethnic Study

The study advances knowledge that can affect how a provider might treat different patients because it is based on a more diverse population than earlier heart risk studies.

“We’ve seen this relationship between irregular [sleep] patterns,” and heart health in earlier studies, but this study “spanned gender, spanned economic status, and spanned education—across the board,” Batts said. “That is where it gets very, very interesting.”

Until MESA, the Framingham, Massachusetts study, launched in 1948, was the study doctors referred to for more than 65 years.

Framingham was used to create 10-year risk models based on many factors, including sleep, with data gathered by following Framingham families’ heart health and genetics across decades. Using the risk model meant “we would put a patient’s data into a calculator and say, ‘This is your risk.’ And we would base our therapies on that,” Batts explained.

The original MESA study, published in 2015, refined that calculation by looking at actual physical measures such as hardening of the arteries and led to a new risk calculator

“No one's ever really thought about if sleep is quite variable. Or what if your bedtime is quite variable? And that seems to be a problem based on the results of this study,” said U.S. Air Force Col. (Dr.) Matthew Brock, chief of the San Antonio Market Sleep Disorders Center at Wilford Hall, the largest sleep center in the Defense Health Agency.

The study was notable not only because it was done in a diverse population, like the military, but also because it factored in health conditions that could skew results, including severe sleep apnea, body mass index, and prevalent cardiovascular disease, Brock explained.

While the study was in older patients, and the military population tends to be younger, healthy patients, “developing good habits, and good sleep duration, and timing when you're young, is important,” Brock said.

The Bottom Line

“Although it might not say this is a direct link, the study should cause at least a hypothesis-generating idea, and I think that's what this does, and it builds upon other literature,” Batts said.

That’s important for the military population with its differing sleep patterns based on type of work or deployment, Batts said. The DHA and the armed services emphasize the importance of sleep as part of Total Force Fitness and through service policies such as the Army’s Performance Triad.

For Batts, the bottom line is communication between patients and providers about sleep, adding, “How do we tie it in and make it substantive for providers to have a conversation about sleep with their patients?” By having those conversations as early as pediatric care, providers could address lifestyle habits that may prevent poor heart health, he said.