Sleep and Ideal Cardiovascular Health

During the AHA’s Scientific Session 2021, heart health, defined by the Life’s Simple 7 metric, was often woven into health equity conversations.

Empirical evidence consistently supports AHA’s recognition of these seven risk factors that people can avoid or improve on through lifestyle changes to help achieve ideal cardiovascular health. Regardless of how challenging this goal is for the average American, Life’s Simple 7 is an essential benchmark for staying heart-healthy.

More attention is now being directed at the role of sleep in maintaining heart-healthy lifestyle practices. Sleep plays an important role in overall health and well-being. In-kind, there exists a reciprocal relationship between the quality of one’s diet, physical activity, and stress on the quality of sleep achieved. Ideally, sleep needs to be deep and restorative to support good cardiovascular health. Specifically, the Centers for Disease Control and Prevention recommend that adults between 18-65 years aim for at least seven hours of quality sleep per night. However, sleeping well is not common. 4 in 10 adults report consistently good sleep at night, and 50 million to 70 million American adults suffer from chronic sleep problems or sleep disorders.

As an early career epidemiologist, who was not too long ago a pre-doctoral candidate, I am familiar with several factors that contribute to trouble with sleep. These have included staying up late to work on an analysis or drafting a manuscript whose internal deadline was already past due; following up on emails while binging a popular streaming series and munching on some snacks; juggling a busy household with two young children that always find a reason to wake up sometime after midnight. Perhaps these experiences are relatable. Often lifestyle choices, poor sleep habits, stress, and medical conditions can play a role in why you can’t sleep.


  • A glass of wine before bed might not interfere with your ability to drift off but indulging in more servings of alcohol before bedtime may impair your sleep by interfering with your sleep cycle, especially REM sleep. This leads to fragmented, unrefreshing rest.

Poor Sleep Habits

  • Habits that make it harder to fall and stay asleep may include (1) staying up late, (2) watching television in bed, (3) playing or browsing on your phone in bed, (4) having an irregular sleep schedule. Simple lifestyle changes to your nightly routines could help to remedy these issues.

Bed Sharing

  • Whether with a partner, child, or pet, reduced sleep quality can be caused by sharing your bed. Anything that can make you uncomfortable (i.e., snores, crowding, pulled covers, or mismatched sleep condition preferences like temperature, light, or noise level) will disrupt your sleep.

Poor Sleep Environment

  • Sleeping environments that are too hot or too cool will disrupt your sleep. Sleep experts recommend a bedroom temperature at a moderate climate between 65 to 72 degrees Fahrenheit at night. The body needs to cool at night for the most refreshing sleep, but a too-cold room will cause you to wake up. Don’t forget about light exposure. Whether it’s from a reading lamp, television, streetlight, or even the glow from a device, this could be enough to signal your brain to wake up.


  • Some folks may argue that coffee has no effect on their ability to sleep at night and will enjoy a cup before bed. However, caffeine has a half-life of three to five hours, so even a late afternoon caffeinated beverage can disrupt your sleep later that night.


  • Often the events of the day that creep back into our minds at night are not the positive experiences but the ones that fill our minds with worry and stress. Stress is one of the most cited symptoms of sleep problems.


  • Exercise, like an evening walk, is excellent for fostering better sleep. But intense, heart-pumping, and sweat-inducing cardio workouts within three hours of your bedtime may be too much. Both your body temperature and heart rate naturally drop as you fall asleep. Exercise stimulates your entire nervous system and raises these two body functions making it difficult to sleep.

Snack Choices

  • Snacks or meals high in fat or protein consumed right before bedtime can overstimulate your digestive system, cause heartburn and make it difficult to sleep. A late-night sugar rush can also lead to hunger pangs and drops in blood sugar, causing you to wake up.

Sleep Disorders and Mental Health

  • Importantly other factors like sleep disorders and mental health problems can make it difficult to sleep. You should talk with your doctor if you suspect that a medical or mental health condition may be contributing to your poor sleep.

Insufficient sleep and poor sleep quality, in addition to sleep disorders, are linked to a wide range of adverse health effects. Major physical and mental health consequences include anxiety, bipolar disorder, hormone imbalances, weakened immune system, cardiovascular disease, and major heart disease risk factors like obesity, inflammation, Type 2 diabetes, high blood pressure. Additionally, poor sleep is linked to overall decreased quality of life and increased mortality risk.

If good sleep habits are not currently part of your daily routine, consider some useful strategies to alleviate some of the factors that have interfered with your quality and quantity of sleep. Here in this infographic are a few tips and techniques developed by AHA to help those who do not have a sleep disorder make small daily changes to establish healthier sleep habits.

Working to alleviate factors that contribute to insufficient sleep and poor sleep quality may also be another critical metric for cardiovascular health. Preliminary findings presented at the AHA’s 2021 Epidemiology and Prevention/Lifestyle and Cardiometabolic Health Scientific Sessions recommended revising the AHA’s Life’s Simple 7 to include sleep as a metric creating a new “Simple 8 or Essential 8” metric measuring cardiovascular health. The study’s lead investigator, Nour Makarem, Ph.D., explained that while sleep is a health behavior that people engage in every day, like diet and exercise, it has received far less attention. However, increasing evidence links sleep to heart disease and risk factors for cardiovascular disease.

Along with her team of investigators, Dr. Makarem assessed whether a cardiovascular health score that includes the Life’s Simple 7 combined with sleep metrics would be more strongly associated with cardiovascular disease than the Life’s Simple 7 score. The study found that when at least one measure of sleep was added with the Life’s Simple 7 measures, the new heart health score was more strongly associated with cardiovascular disease than the traditional Life’s Simple 7. The results were compelling and showed, for example, that study participants who received seven to eight hours of sleep a night in addition to meeting Life’s Simple 7 guidelines had up to 61% lower odds of having heart disease. Those who got less than six hours of sleep scored lower for overall cardiovascular health and had a higher prevalence of overweight and obesity, Type 2 diabetes, and high blood pressure. Sleep duration and the other sleep metrics included in the study made the cardiovascular health scores more predictive of cardiovascular disease risk than the seven metrics alone.


Like several current Life’s Simple 7 measures, clocking 7-9 hours of sleep per day can be challenging. However, the traditional cardiovascular health metric may need to be revisited for a potential upgrade in providing yet another vital benchmark for predicting and promoting ideal cardiovascular health.


  1. Lloyd-Jones, Donald M., et al. “Defining and setting national goals for cardiovascular health promotion and disease reduction: the American Heart Association’s strategic Impact Goal through 2020 and beyond.”Circulation 4 (2010): 586-613.
  2. https://www.heart.org/en/health-topics/sleep-disorders/sleep-and-heart-health
  3. https://www.heart.org/en/news/2020/03/06/sleep-should-be-added-as-measure-of-heart-health-study-says
  4. https://www.verywellmind.com/reasons-for-not-sleeping-well-and-how-to-fix-350760
  5. https://www.heart.org/en/healthy-living/healthy-lifestyle/sleep/sleep-well-infographic
  6. https://www.ahajournals.org/doi/10.1161/circ.141.suppl_1.36

“The views, opinions and positions expressed within this blog are those of the author(s) alone and do not represent those of the American Heart Association. The accuracy, completeness and validity of any statements made within this article are not guaranteed. We accept no liability for any errors, omissions or representations. The copyright of this content belongs to the author and any liability with regards to infringement of intellectual property rights remains with them. The Early Career Voice blog is not intended to provide medical advice or treatment. Only your healthcare provider can provide that. The American Heart Association recommends that you consult your healthcare provider regarding your personal health matters. If you think you are having a heart attack, stroke or another emergency, please call 911 immediately.”



Start 2021 in a Good Night Sleep

Picture source: (Kuehn 2019)

Should you make new year’s resolutions? Many may think the new year’s resolutions are meaningless. Especially after a year of frustration and uncertainty, New year’s resolutions seem less encouraging. A few small and attainable goals could help to provide a sense of purpose and improve our well-being. The most popular goals for new year’s resolutions include exercise more, eat healthier, and get rid of bad habits.

[1]Sleep deprivation is one of the common bad habits in modern society. According to a study in the Centers for Disease Control and Prevention’s (CDC) Morbidity and Mortality Report, 1 in 3 Americans don’t get enough sleep on a regular basis. To promote optimal health and well-being, the American Academy of Sleep Medicine and the Sleep Research Society recommend at least 7 hours of sleep each night for adults aged 18-60 years old. The adverse effects of sleep deprivation (less than seven hours per day) include obesity(Beccuti and Pannain 2011), diabetes(Shan et al. 2015), high blood pressure(Gangwisch et al. 2006), cardiovascular disease(Nagai, Hoshide, and Kario 2010; Kuehn 2019), stroke, and mental distress(Baglioni et al. 2016). It’s undeniable that having sufficient sleep is essential to our optimal health and well-being. Here are some helpful tips to start your 2021 with a good night’s sleep.

Bedroom: light, noise, and temperature

Research shows artificial light at night can disrupt circadian rhythms and cause adverse effects on sleep(Aulsebrook et al. 2018). A dim bedroom environment can help the body to recognize the time to rest. Electronic devices emit blue lights, many studies show that blocking blue light is beneficial for patients to suffer from insomnia(Janků et al. 2020). Restricting electronic devices before sleep or using blue-light blocking approaches are helpful to maintain a good quality sleep.

Noise can also affect sleep(Basner and McGuire 2018). Try to reduce noise in the bedroom environment could fall asleep faster and minimize disruption during sleep. Both environmental and body temperature impact sleep duration and sleep quality(Troynikov, Watson, and Nawaz 2018). Increased bedroom and body temperature decrease sleep quality. Finding a comfortable temperature for yourself will improve sleep quality. For most people, the desirable bedroom temperature is around 70 ˚F (20 ˚C). Taking a good bath or shower before bed will prepare the body to adjust to a favorable temperature for sleep.

De-stress: mentally and physically

Most of us have experienced some form of insomnia when we have something in our minds. Integrative approaches to insomnia such as mind-body therapies (mindfulness mediation, yoga, tai chi) have been shown beneficial to de-stress the body as well the mind(Zhou, Gardiner, and Bertisch 2017). Exercise is beneficial for the overall well-being, can improve the quality of sleep(Kelley and Kelley 2017). Various approaches can help relax the body and mind, finding your favorite ones requires a little bit of exploration.

Routine: timing and time

We are creatures of habits. Especially when it comes to sleep. Disruption of the circadian clock adversely affects sleep, which causes cardiovascular diseases(Chellappa et al. 2019). Cultivating a wake-up and night-time routine will have profound impacts on the overall performance. When to go to bed is different for everyone. Anecdotally, it’s best to go to bed earlier and wake up early each day. This may not work for everyone’s schedule. Keeping the recommended amount of sleep is more important than strictly enforcing yourself against your circadian clock.

Food and drink

Investigation of the impact of food choice and consumption on sleep is an emerging field. Early clinical studies investigated the effects of certain macronutrients such as carbohydrate, protein or fat on daytime alertness and nighttime sleep. Some popular sleep–promoting foods, such as milk, fatty fish, cherries, and kiwifruit have been reported(St-Onge, Mikic, and Pietrolungo 2016). Avoid late caffeine consumption(Clark and Landolt 2017) and alcohol(Thakkar, Sharma, and Sahota 2015) are common practices to improve sleep quality.

All of the above are potential strategies for sleep improvement. Making small adjustments in your sleep hygiene routine could have a promising outcome. The key is to start small and stick to it until it incorporates into your day-to-day life.


Aulsebrook, Anne E., Therésa M. Jones, Raoul A. Mulder, and John A. Lesku. 2018. “Impacts of Artificial Light at Night on Sleep: A Review and Prospectus.” Journal of Experimental Zoology Part A: Ecological and Integrative Physiology. https://doi.org/10.1002/jez.2189.

Baglioni, Chiara, Svetoslava Nanovska, Wolfram Regen, Kai Spiegelhalder, Bernd Feige, Christoph Nissen, Charles F. Reynolds, and Dieter Riemann. 2016. “Sleep and Mental Disorders: A Meta-Analysis of Polysomnographic Research.” Psychological Bulletin. https://doi.org/10.1037/bul0000053.

Basner, Mathias, and Sarah McGuire. 2018. “WHO Environmental Noise Guidelines for the European Region: A Systematic Review on Environmental Noise and Effects on Sleep.” International Journal of Environmental Research and Public Health. https://doi.org/10.3390/ijerph15030519.

Beccuti, Guglielmo, and Silvana Pannain. 2011. “Sleep and Obesity.” Current Opinion in Clinical Nutrition and Metabolic Care. https://doi.org/10.1097/MCO.0b013e3283479109.

Chellappa, Sarah L., Nina Vujovic, Jonathan S. Williams, and Frank A.J.L. Scheer. 2019. “Impact of Circadian Disruption on Cardiovascular Function and Disease.” Trends in Endocrinology and Metabolism. https://doi.org/10.1016/j.tem.2019.07.008.

Clark, Ian, and Hans Peter Landolt. 2017. “Coffee, Caffeine, and Sleep: A Systematic Review of Epidemiological Studies and Randomized Controlled Trials.” Sleep Medicine Reviews. https://doi.org/10.1016/j.smrv.2016.01.006.

Gangwisch, James E., Steven B. Heymsfield, Bernadette Boden-Albala, Ruud M. Buijs, Felix Kreier, Thomas G. Pickering, Andrew G. Rundle, Gary K. Zammit, and Dolores Malaspina. 2006. “Short Sleep Duration as a Risk Factor for Hypertension: Analyses of the First National Health and Nutrition Examination Survey.” Hypertension. https://doi.org/10.1161/01.HYP.0000217362.34748.e0.

Janků, Karolina, Michal Šmotek, Eva Fárková, and Jana Kopřivová. 2020. “Block the Light and Sleep Well: Evening Blue Light Filtration as a Part of Cognitive Behavioral Therapy for Insomnia.” Chronobiology International. https://doi.org/10.1080/07420528.2019.1692859.

Kelley, George A., and Kristi Sharpe Kelley. 2017. “Exercise and Sleep: A Systematic Review of Previous Meta-Analyses.” Journal of Evidence-Based Medicine. https://doi.org/10.1111/jebm.12236.

Kuehn, Bridget M. 2019. “Sleep Duration Linked to Cardiovascular Disease.” Circulation 139 (21): 2483–84. https://doi.org/10.1161/CIRCULATIONAHA.119.041278.

Nagai, Michiaki, Satoshi Hoshide, and Kazuomi Kario. 2010. “Sleep Duration as a Risk Factor for Cardiovascular Disease- a Review of the Recent Literature.” Current Cardiology Reviews. https://doi.org/10.2174/157340310790231635.

Shan, Zhilei, Hongfei Ma, Manling Xie, Peipei Yan, Yanjun Guo, Wei Bao, Ying Rong, Chandra L. Jackson, Frank B. Hu, and Liegang Liu. 2015. “Sleep Duration and Risk of Type 2 Diabetes: A Meta-Analysis of Prospective Studies.” Diabetes Care. https://doi.org/10.2337/dc14-2073.

St-Onge, Marie Pierre, Anja Mikic, and Cara E. Pietrolungo. 2016. “Effects of Diet on Sleep Quality.” Advances in Nutrition. https://doi.org/10.3945/an.116.012336.

Thakkar, Mahesh M., Rishi Sharma, and Pradeep Sahota. 2015. “Alcohol Disrupts Sleep Homeostasis.” Alcohol. https://doi.org/10.1016/j.alcohol.2014.07.019.

Troynikov, Olga, Christopher G. Watson, and Nazia Nawaz. 2018. “Sleep Environments and Sleep Physiology: A Review.” Journal of Thermal Biology. https://doi.org/10.1016/j.jtherbio.2018.09.012.

Zhou, Eric S., Paula Gardiner, and Suzanne M. Bertisch. 2017. “Integrative Medicine for Insomnia.” Medical Clinics of North America. https://doi.org/10.1016/j.mcna.2017.04.005.

[1] Picture source: (Kuehn 2019)


“The views, opinions and positions expressed within this blog are those of the author(s) alone and do not represent those of the American Heart Association. The accuracy, completeness and validity of any statements made within this article are not guaranteed. We accept no liability for any errors, omissions or representations. The copyright of this content belongs to the author and any liability with regards to infringement of intellectual property rights remains with them. The Early Career Voice blog is not intended to provide medical advice or treatment. Only your healthcare provider can provide that. The American Heart Association recommends that you consult your healthcare provider regarding your personal health matters. If you think you are having a heart attack, stroke or another emergency, please call 911 immediately.”


Why We Sleep, and Why Don’t We Let Hospitalized Patients Sleep?

Last month, I wrote about my newfound fascination with wearables and the physiological parameters I now measure on myself. One of these metrics is my “recovery score,” (Figure 1) which is heavily determined by the quantity, quality, and consistency (the regularity of the times at which I go to sleep each night and wake up each morning) of my sleep. Now that I wake up each morning being graded by my wearable on how well I slept, I have implemented strategies to improve my scores: wearing an eye mask, using blue light-blocking glasses at night, using my phone in bed, going to sleep at a regular time. These indeed have improved my recovery scores, and I honestly feel I sleep more efficiently as a result – I feel just as rested after 6 hours of sleep now as I previously did only with 7-8 hours of sleep.

Figure 1: Sample recovery score from my wearable device (Whoop strap).

Figure 1: Sample recovery score from my wearable device (Whoop strap).

My focus on my own sleeping habits led me to start reading the book, “Why We Sleep” by Dr. Matthew Walker. It is a fascinating review of the physiological role of sleep (or at least, the best knowledge we have of it), and I recommend it to anyone interested in the topic. While sleep has been studied intensely for decades, there still is much we do not know about how it benefits our bodies and minds. Some recent high-profile studies on sleep caught my attention though, including one published in Science that implicates the sleep-wake cycle in the regulation of the Alzheimer’s Disease-related tau protein in the brain.1,2 Another recent study suggests that when we cannot repay accrued “sleep debt” over the course of a week, at least with regards to its effects on metabolic dysregulation.3 However, as I continued to read about the importance of sleep and its health benefits, I could not help but think about some of the most sleep-deprived people we encounter regularly – our own patients.

Anyone who has worked in the inpatient hospital setting knows that admitted patients are regularly disrupted throughout the evenings in the hospital, and it is a rare evening they can get a full, restful night’s sleep. Indeed, one study showed that inpatients on average get 83 fewer minutes of sleep compared to their sleep duration at home.4 Some factors preventing sleep are related to the nature of their hospitalization and are difficult to circumvent – severe pain, hemodynamic instability, infections that produce significant discomfort (e.g., fever, cough).

Yet many factors are systematic and iatrogenic. Often, nurses receive orders to check vital signs every 4 hours, and thus are required to check in on patients in the middle of the night to measure blood pressures. Intravenous medication infusion pumps alarm seemingly every 5 minutes. Daily lab work is ordered to be performed early in the mornings, so that results will be ready by the time physician teams begin their rounds. And in teaching institutions, medical students and housestaff “pre-round” in the early hours (sometimes as early as 5:00am), waking their patients to briefly interview and examine them (Figure 2).

elderly man in hospital

Figure 2: Depiction of early morning “pre-rounding.”

While clearly many hospitalized patients are in the hospital precisely because they need close monitoring, there is a large subset of admitted patients who, despite the need to be hospitalized, could be provided an environment in which they can get a full night’s rest. Many hospital systems are attuned to these issues, and I am proud to say that mine is as well, but many of the systematic factors that interfere with sleep are unfortunately just part of the rounding culture at academic hospital centers (early labs, pre-rounding, etc.).

A recent Twitter thread from a former co-resident of mine, Dr. Dan Wheeler (@WheelerMed), made me reflect on the purpose of morning rounds. Dr. Wheeler’s thread highlighted the heterogeneity in how different teams rounded and the challenges this may pose to trainees. Yet I could not help but think that the major problem with rounds is that, in my opinion at least, it is not patient-centered. In fact, given that many features of rounds interfere with an inpatient’s ability to obtain adequate sleep, rounds actually impede patient recovery.

Isn’t patient recovery our ultimate goal? When I spend so much time trying to improve my own “recovery score,” shouldn’t I also focus energy to improve the recovery scores of those who need it much more than I do?

As trainees, we arguably do not have much control of the rounding schedule and culture. But, my goal in writing this post is to challenge us to be mindful of these factors when we eventually do have the capacity to restructure the inpatient hospital routine, to focus appropriate attention and efforts to allow for adequate patient sleep and recovery. This field may actually be an exciting avenue for research, particularly in wearables that can appropriately monitor inpatients’ physiological parameters during sleep without disturbing them.

So before you go entering your patients’ rooms at 5:30am in the morning to pre-round, I encourage you to take an extra moment to ask yourself whether it’s truly necessary to wake them, or whether you can allow them the chance to improve their recovery score just a bit more.



  1. Holth JK, Fritschi SK, Wang C, Pedersen NP, Cirrito JR, Mahan TE, Finn MB, Manis M, Geerling JC, Fuller PM, Lucey BP, Holtzman DM. The sleep-wake cycle regulates brain interstitial fluid tau in mice and CSF tau in humans. Science. 2019;363:880–884.
  2. Noble W, Spires-Jones TL. Sleep well to slow Alzheimer’s progression? Science. 2019;363:813–814.
  3. Depner CM, Melanson EL, Eckel RH, Snell-Bergeon JK, Perreault L, Bergman BC, Higgins JA, Guerin MK, Stothard ER, Morton SJ, Wright KP. Ad libitum Weekend Recovery Sleep Fails to Prevent Metabolic Dysregulation during a Repeating Pattern of Insufficient Sleep and Weekend Recovery Sleep. Curr Biol. 2019;29:957-967.e4.
  4. Wesselius HM, van den Ende ES, Alsma J, Ter Maaten JC, Schuit SCE, Stassen PM, de Vries OJ, Kaasjager KHAH, Haak HR, van Doormaal FF, Hoogerwerf JJ, Terwee CB, van de Ven PM, Bosch FH, van Someren EJW, Nanayakkara PWB, “Onderzoeks Consortium Acute Geneeskunde” Acute Medicine Research Consortium. Quality and Quantity of Sleep and Factors Associated With Sleep Disturbance in Hospitalized Patients. JAMA Intern Med. 2018;178:1201–1208.