Scientists Find ‘Night Owl’ Sleep Pattern Increases Risk of Heart Attack, Stroke

After an average of 14 years, researchers identified heart attack and stroke prevalence in participants and compared the instances to their LE8 scores. Those who were self-proclaimed night owls and had lower scores were among the most affected by heart events, which led researchers to determine that night owls had a 16% higher risk of experiencing a heart attack or stroke compared to “definite” morning people or those who had an “intermediate sleep-wake preference,” meaning they fell somewhere in between a morning person and a night owl.

Specifically, researchers identified that increased heart disease risk in night owls was largely driven by poor diet, high nicotine use, poor sleep, infrequent exercise, high body weight, and unmanaged blood sugar.

However, “When these risk factors were accounted for statistically, the excess cardiovascular risk associated with being a night owl was largely eliminated,” says Allen Taylor, M.D., a cardiologist and chairman of cardiology at MedStar Heart and Vascular Institute. That means the findings indicate an association, rather than causation, between delayed sleep and heart health. But sleep remains an important pillar.

How sleep affects heart health

Each individual’s circadian rhythm varies slightly, but the human brain is in large part influenced by light (or lack thereof) to release the hormones necessary to wake up and fall asleep, which is why most of us feel tired when it gets dark and energized by sunlight. So, it makes sense that resisting such a natural cycle may encourage poor health.

“Sleep supports cardiovascular health through physiological changes in heart rate and blood pressure,” says Carleara Weiss, Ph.D., M.S., R.N., a sleep scientist, assistant professor at the State University of New York, and sleep educator at Aeroflow Sleep.

“Adequate sleep duration and quality also regulate immune function and hormone levels, and reduce inflammatory response,” Weiss adds. “Oxygen saturation is another important aspect of sleep, and cardiovascular health is negatively impacted in people with untreated obstructive sleep apnea.” (Sleep apnea is characterized by lack of oxygen during sleep.)

Sleep also regulates the hormones ghrelin, which signals hunger, and leptin, which signals satiety, she explains. Therefore, poor sleep may trigger cravings for high-fat and processed foods, promoting weight gain and, therefore, potentially leading to negative heart health impacts.

How to get better sleep

“Behavioral changes are often the first step in readjusting sleep and circadian rhythms,” says Weiss. This might mean shifting bedtimes or using light therapy when needed to cue your body to wake up (like the Hatch alarm clock). Of course, changing the modifiable LE8 factors—like diet and exercise—can also inherently improve lifestyle and sleep routines, notes Dr. Taylor. It’s all connected.

However, there are specific cases, such as night shift workers and people with delayed sleep phase syndrome, for example, who may need assistance from a medical provider to ensure quality sleep, says Weiss.

The bottom line

Instituting positive cardiovascular health habits (like getting good sleep, eating a nutritious diet, mitigating stress, etc.), the risk associated with the night owl sleep schedule “can be substantially reduced or eliminated,” says Dr. Taylor. In other words, sticking to heart-healthy habits—which includes getting good sleep—is more important than when you hit the hay.