Sleep Like Your Heart Depends on It
- Julie Peterson
- 5 days ago
- 9 min read
A Quick Guide to Heart-Healthy Rest
Science has shown that sleep disorders—deficiencies in the quantity, timing, and quality of sleep—are risk factors for cardiovascular disease (CVD). This is important as CVD remains the leading cause of death globally, as well as in the United States.
Sleep disorders can stem from a wide variety of factors, including air pollution, lifestyle, traumatic brain injury, or daylight savings time. In light of the connections between heart health and getting adequate, daily amounts of restorative sleep, researchers are searching for ways to help people get their best possible sleep.
Cardiovascular Disease
The World Health Organization (WHO) defines CVDs as “a group of disorders of the heart and blood vessels and include coronary heart disease, cerebrovascular disease, rheumatic heart disease and other conditions.”
The magnitude of death caused by CVD is shocking: According to the World Health Organization, an estimated 17.9 million people globally die each year from CVD. The US Centers for Disease Control and Prevention (CDC) says that, in the US, a person dies every 33 seconds from this disease. Death rates vary by sex, race, and ethnicity, but CVD is still the leading cause of death for people of most racial and ethnic groups.
Risk of CVD can be increased by one’s lifestyle choices, health conditions, environment, family history, or age—hence they are called “risk factors” for CVD. According to the CDC, major risk factors for CVD include high blood pressure, high cholesterol, obesity, and smoking.
The public has long been warned about artery-clogging junk food, smoking, obesity, and a sedentary lifestyle as risk factors for heart problems. Likewise, patients who have high blood pressure, chronic inflammation, atherosclerosis, diabetes, and certain genetic factors are routinely educated about their higher risk for developing debilitating or deadly heart or vascular problems.
Now, researchers are focusing on lack of sleep as another serious risk factor. It has become widely accepted throughout the scientific and medical community that without enough quality sleep, one’s risk of CVD increases.
Not Sleeping Well or Enough
According to the CDC, people need less sleep as they age. The CDC also reminds us that sleep helps the body repair itself. But people aren’t getting what is recommended.
In every US state, “30% to 44% of adults … are not getting enough sleep,” Michael Twery, PhD, said in 2020 when he led the National Heart, Lung, and Blood Institute’s National Center on Sleep Disorders Research.
It’s not just in the US, it’s all over the world, he added. “Whether we’re talking about South Africa…Kenya, Vietnam, Bangladesh, Indonesia, India, there is a large percentage of people in every country worldwide, which are experiencing insufficiency of regular sleep.”
Dangers of Inadequate Sleep
Understanding the specific effects of sleep deprivation on heart function and overall cardiovascular health is a continuing focus of researchers like Twery, who said, “The need for sleep is a non-negotiable requirement for life…Sleep gives your heart and vascular system a much-needed rest.” When the body can’t work as it should, problems arise.
American Heart Association researchers found that a lack of sleep is associated with increased calcium buildup in the heart’s arteries.
For example, American Heart Association researchers found that a lack of sleep is associated with increased calcium buildup in the heart’s arteries, which causes plaques that can put one at risk for a heart attack. In the study, sleeping one hour less each night increased the risk of arterial calcium build-up by 33%. Sleeping less than six hours per night put people at the greatest risk.
Not getting enough sleep also reduces the body’s production of certain appetite-suppressing hormones, which may lead to weight gain. Several studies have linked not getting enough sleep to an imbalance in hormones that regulate metabolism.
“Exactly how sleep influences the coronary arteries is still being studied, but we do know that not getting enough sleep is associated with risk factors for heart disease,” says cardiac surgeon A. Marc Gillinov, MD, at Cleveland Clinic.
Why is Sleep Elusive?
There are numerous and varied reasons for sleep deprivation. Most research studies to date have examined one or two factors for their contributions to inadequate sleep, yet it is likely that a person’s lack of sufficient sleep results from a combination of multiple influences. These contributing factors can be classified into categories, some of which may overlap.
1. Circumstances of Life
There are personal situations and day-to-day realities a person faces, some controllable and some not, that can cause sleep loss.
Examples include shift work (especially shifts that are partly or fully during nighttime hours), alcohol misuse, intake of stimulants such as caffeine late in the day, bad sleep-related habits (staying up late or using electronics in bed), high stress, and environmental factors.
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Air pollution, a warm bedroom, high levels of carbon dioxide, and too much ambient noise may adversely affect the ability to get a good night’s sleep, suggests a study from researchers with the Perelman School of Medicine at the University of Pennsylvania and the University of Louisville. The study is one of the first to measure multiple environmental variables in the bedroom.
Emerging evidence has also demonstrated that environmental factors in the whole household and at the neighborhood-level can alter healthy sleep. The “social features of environments, family, social cohesion, safety, noise, and neighborhood disorder” can cause restless or sleepless nights for all ages, said a 2018 study in Current Epidemiological Reports.
Pollution is another environmental issue that can include “exposure to heavy metals, noise pollution, light pollution, second-hand smoke, and air pollutants,” said a 2020 article in Environmental Research. These all have negative consequences on sleep outcomes.
Pollution is another environmental issue that can include “exposure to heavy metal, noise pollution, light pollution, second-hand smoke, and air pollutants,” said a 2020 article in Environmental Research. These all have negative consequences on sleep outcomes, including the inability to fall asleep and stay asleep, reach the deepest levels of sleep, sleep all night without being roused, and daytime drowsiness.
2. Medical Conditions
Mental health has a major impact on sleep and vice versa. This can set up a cycle that reinforces itself as it gets worse. An example would be depression that makes it harder to sleep, leading to sleep deprivation, which then makes one feel even more depressed. Other mental health issues that can affect sleep include anxiety, bipolar disorder, panic disorder, post-traumatic stress disorder (PTSD), and somniphobia (fear of sleep).
Everyone has experienced a short-term illness (colds, flu) or pain (strained muscles, broken bones) that has made sleep difficult.
But there are more than 80 sleep disorder conditions, according to the National Library of Medicine. Some stem from long-term medical problems, such as degenerative brain disorders (Alzheimer’s disease or Parkinson’s disease), concussions and traumatic brain injuries, stroke, cancer, and chronic pain. Also, medications, such as corticosteroids and stimulants, can cause insomnia, wakefulness, or change the quality of sleep.
Common sleep disorders include insomnia (being unable to fall asleep and stay asleep), restless leg syndrome (a tingling or prickly sensation in the legs with a powerful urge to move them), narcolepsy, circadian rhythm issues, and parasomnia (walking, talking, eating during sleep).
A major malady is obstructive sleep apnea (OSA), a breathing disorder in which the person stops breathing dozens and even hundreds of times during sleep.
“Humans are supposed to breathe through their nose … in many people, for various reasons, there is an obstruction ... one of the most common obstructions … is where the tongue … falls into the back of the throat and blocks the airway,” said Twery. “Where we struggle to breathe, we’re not getting enough oxygen; we’re not blowing off our C02 … [and that causes] our brain to send an alarm bell that says, ‘Hey, we’ve got a big problem!’ to wake us up. It is also causing changes in the pressure in the chest.” Twery said these changes can cause health abnormalities that eventually can lead to clinical conditions such as high blood pressure, arrhythmias, stroke, and arterial disease.
OSA is linked to issues like obesity, head and facial features, and “airway tone,” which refers to the caliber of the airway muscles. Because many people are unaware that they have OSA, it often goes untreated, which can reduce lifespan.
One source of information about OSA is the landmark Wisconsin Sleep Cohort Study, which has followed 1,500 participants for more than three decades. The study “discovered that people with sleep apnea had a 20% higher chance of dying from cardiovascular issues, particularly stroke and heart disease,” said Myohab.com, a website dedicated to helping people resolve tongue, mouth, and breathing issues.
People can become aware of sleep apnea when a spouse or family member complains of loud snoring or the snorer realizes they are always tired or have headaches during the day. A sleep study is the only way to achieve a definitive diagnosis of OSA, and this can be ordered by a sleep specialist, pulmonologist, or ENT (ear, nose, and throat) doctor.
A trip to the dentist can also identify airway obstructions according to studies. “When you consider that obstructive sleep apnea affects approximately 20% of US adults, of whom about 90% are undiagnosed, it is imperative to evaluate all our patients for the presence of any physiologic and behavioral predisposing factors,” says Claire Stagg, DDS, in an interview. Stagg is founder and owner of Health Connections Dentistry and author of Smile, It’s all Connected! She also points out that sleep apnea can sometimes be prevented with early detection of structural abnormalities in developing children.
Tips to Improve Sleep Quality and Quantity
To prepare for a good night’s sleep, counselors first suggest making sure the bedroom is quiet, dark, and cool. People should try to follow a regular sleep schedule and avoid drinking caffeinated beverages late in the day. Sleep counselors also advise people to avoid blue and green light before bed, which means shutting off televisions and cell phones and other electronic devices.
For teens, an Australian research group found that those who established a nighttime routine and limited the use of digital devices before bed got 40 minutes more sleep a night.
For teens, an Australian research group found that those who established a nighttime routine and limited the use of digital devices before bed got 40 minutes more sleep a night.
The National Library of Medicine’s Medline Plus website offers advice on “sleep hygiene” that includes:
Avoid nicotine.
Exercise regularly, but don't exercise too late in the day.
Avoid alcoholic drinks before bed.
Avoid large meals and beverages late at night.
Don't take a nap after 3 p.m.
Relax before bed, for example by taking a bath, reading or listening to relaxing music.
Get enough sunlight exposure during the day.
Don't lie in bed awake; if you can't sleep for 20 minutes, get up and do something relaxing.
See a doctor if you have continued trouble sleeping.
Sleep Research is Ongoing
It’s impossible for any one study to account for every factor that causes sleep loss. For example, PTSD can cause sleep loss, and sleep loss can cause increased cortisol, which can lead to inflammation that can increase risk of CVD. However, PTSD alone can cause increased cortisol. So, it’s not clear that an increase in cortisol is due to lack of sleep or a concomitant condition.
In addition, there is still much to learn about sleep. For example, there are questions about how sex and age differences can impact sleep loss. Other study topics include the role of inflammation or hormonal changes on sleep.
In a 2021 clinical review published in Europe, an overview on the bidirectional relationship between cardiovascular disease and sleep was done. “While impaired sleep and bad sleep quality are often present in patients with cardiovascular diseases due to the underlying disease…, short duration of sleep and sleep fragmentation as such could increase the risk of developing coronary artery disease, arrhythmia, and heart failure,” said the article in the European Journal of Preventive Cardiology.
The clinical review points out that “a major difficulty in this field is that population-based studies are hampered by individual and inter-individual confounding factors (environment, social conditions, cultural habits). In addition, duration and quality of sleep are often self-reported and not assessed objectively, which can lead to controversial results.”
What About Snoozing?
A common debate in many homes is whether the morning snooze button is helpful. Researchers from Stockholm University, who conducted a pair of studies, found that for some people, snoozing is beneficial.
One study found that if people “snoozed” for an extra 30 minutes, their performance on cognitive tests was normal or improved, compared with those who had “abrupt awakenings.”
“Our findings show that those who snooze on average sleep slightly shorter and feel more drowsy in the morning compared to those who never snooze,” study co-author Tina Sundelin said. “But there were no negative effects of snoozing on cortisol release, morning tiredness, mood, or sleep quality throughout the night.”
Studies also show that “catching up” on sleep has benefits.
Research presented in 2024 at the European Society of Cardiology Congress looked at irregular sleep schedules, as are common in teens, shift workers, and caretakers who may not get enough sleep during the week and then want to nap or sleep in on weekends.
“Sufficient compensatory sleep is linked to a lower risk of heart disease,” said study co-author Yanjun Song of the National Centre for Cardiovascular Disease in Beijing. “The association becomes even more pronounced among individuals who regularly experience inadequate sleep on weekdays.”
*Julie Peterson writes science-based articles about holistic health, environmental issues, and sustainable living from her small farm in Wisconsin.
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