Sleep’s Heartfelt Connection Goes Deeper Than Hours

Cardiologists Urged to Look Beyond Duration for Optimal Cardiovascular Health

While a good night’s sleep has long been celebrated for its health benefits, from the Dalai Lama’s praise to Benjamin Franklin’s wisdom, new research suggests the American Heart Association’s recognition of sleep duration is just the beginning.

Expanding the Sleep Health Framework

The AHA has expanded its “Life’s Simple 8” checklist to include sleep duration, acknowledging strong links between inadequate sleep and adverse cardiometabolic outcomes like obesity, type 2 diabetes, and stroke. However, experts now emphasize that consistency and individual sleep timing, known as chronotype, are equally critical factors for heart health.

Martha Gulati, MD, director of Preventive Cardiology at the Smidt Heart Institute at Cedars-Sinai, highlighted that while 7-9 hours of sleep is associated with positive health markers such as better blood pressure and cholesterol, the depth of sleep health extends further.

Emerging studies underscore this complexity. A 2023 UK study found that self-identified “night owls” showed potentially harmful cardiac remodeling compared to “morning larks.” Furthermore, research in adolescents linked shorter sleep durations to adverse indicators of heart and liver health, suggesting a cumulative impact over time.

The MESA Sleep Ancillary study also revealed that individuals with more irregular sleep schedules—going to bed at different times nightly—exhibited higher coronary artery calcium levels than those with consistent routines.

Julie Marcus, MD, a cardiologist at Weill Cornell Medicine/New York Presbyterian Hospital, stated that addressing poor sleep is a vital, yet often overlooked, aspect of maintaining heart health. She noted that patients need to understand how sleep affects their well-being, and that the conversation about sleep quality involves more than just snoring or breathing cessation.

A Multidimensional Approach to Sleep Health

This year, the AHA released an updated scientific statement that embraces a broader definition of sleep health. This expanded view encompasses not only duration but also timing, regularity, daytime functioning, satisfaction, continuity (the ability to initiate and maintain sleep), and sleep architecture (the different stages of sleep).

Marie-Pierre St-Onge, PhD, a leading sleep health researcher and the AHA statement’s lead author, explained the update aims to reflect the growing body of research. “We want to let people know that sleep is more than just how long you sleep at night,” she commented.

St-Onge pointed to research linking excessive daytime sleepiness with cardiovascular diseases, stroke, and all-cause mortality, as well as the connection between sleep disturbances and hypertension. As of 2024, over 30% of U.S. adults report getting less than the recommended seven hours of sleep per night, according to the CDC, highlighting the widespread impact of insufficient sleep on public health.

Unraveling Sleep’s Impact on Cardiovascular Health

New research is shedding light on the mechanisms through which poor sleep negatively affects cardiometabolic outcomes. St-Onge’s work suggests sleep restriction can increase oxidative stress in artery linings, potentially leading to endothelial dysfunction, while also hindering the body’s ability to combat this stress. She noted that poor sleep quality and duration are linked to immune suppression.

Furthermore, links have been established between sleep regularity and eating patterns. Gulati believes the AHA’s comprehensive statement serves as a critical call to action for greater awareness among patients and healthcare professionals regarding the multifaceted effects of poor sleep health on cardiovascular well-being. She emphasized the need for improved sleep assessment in research to understand effective interventions.

Initiating the Sleep Health Conversation

While the AHA statement does not yet provide clinical guidance, St-Onge stresses the importance of starting conversations about sleep with patients. She suggests open-ended questions like, “How’s your sleep?” can encourage individuals to share their specific concerns, whether it’s difficulty falling asleep, staying asleep, or waking up feeling unrefreshed despite adequate hours.

Marcus agrees that prioritizing sleep health discussions is crucial, even though it presents a challenge as “sleep is not a number” like blood pressure or cholesterol. She believes understanding a patient’s sleep patterns can uncover new modifiable risk factors for enhancing cardiovascular health.

“Sleep is the next target,” Marcus asserted. “We know it impacts health, and it’s just a matter of how do we screen for it.”