Sleep and Cardiovascular Health
Thank you to Xiaoyue Liu, PhD, RN, Post-doctoral Fellow and Yvonne Commodore-Mensah, PhD, MHS, RN, Associate Professor for this article on sleep and cardiovascular health.
What Nurses Need to Know About Sleep and Cardiovascular Health
Understanding the interconnectedness of sleep and cardiovascular health allows nurses and other healthcare providers to help patients reduce their risk of cardiovascular disease and help improve patient outcomes.
Sleep and Cardiovascular Disease
Approximately 70 million Americans suffer from sleep-related issues.[i] Sleep is a complex and dynamic process that plays an essential role in cardiovascular homeostasis.[ii] Current evidence suggests 7 to 9 hours of daily sleep is optimal for adults, and more for children, depending on age.[iii],[iv] However, over one-third of adults in the U.S. report sleep deprivation, and these individuals are more likely to develop cardiovascular disease (CVD) in comparison to adults with normal sleep duration.[v]
Numerous studies have demonstrated that deviations from optimal sleep are associated with CVD risks, such as hypertension, diabetes, coronary heart disease, myocardial infarction, and cardiovascular mortality. The most recent report by the American Heart Association added sleep duration as one of the essential components of cardiovascular health, along with the other components: diet, physical activity, nicotine exposure, body mass index, blood lipids, blood glucose, and blood pressure.3 The recognition of sleep health in Life’s Essential 8TM has emphasized the necessity of incorporating sleep assessment into routine clinical practice for nurses. Sleep health characterizes multiple domains, including regularity, alertness, efficiency, latency, and satisfaction with sleep quality.[vi] As such, a holistic approach is required to better understand the multidimensional aspects of sleep.
Pathways Underlying the Association Between Sleep and Cardiovascular Disease
There are several mechanisms linking sleep to cardiovascular health. Poor sleep is known to influence the pathogenesis of CVD through biological pathways that include autonomic imbalance, inflammation, and impaired glucose regulation.[vii],[viii] Sleep may also result in adverse cardiovascular outcomes through psychological pathways by increasing stress and depression.[ix] In addition, individuals with chronic sleep problems are more likely to engage in unhealthy behaviors such as unhealthy eating, physical inactivity, alcohol consumption, and smoking, which are strongly associated with CVD risk.
Another important mechanism that underlies sleep and CVD is obstructive sleep apnea (OSA). This sleep disorder is characterized by recurrent complete and partial upper airway obstructive events that result in intermittent hypoxemia, autonomic fluctuation, and sleep fragmentation. OSA is prevalent in the general population, but also frequently co-occurs with hypertension, heart failure, atrial fibrillation, and stroke.[x]
Sleep and Cardiovascular Health Disparities
Poor sleep fundamentally contributes to cardiovascular health disparities in vulnerable populations.[xi] Persons from racial/ethnic minority or socioeconomically disadvantaged backgrounds disproportionately suffer from poor sleep. This high burden is considered a main contributor to disparities in cardiovascular health.[xii] One recent study showed that minorities experience increased levels of CVD risk as a result of differences in sleep duration and sleep efficiency, at 41% and 58%, respectively.[xiii]
Social determinants can operate on multiple levels (individual, interpersonal, neighborhood, and system) that both independently and synergistically influence sleep.[xiv] These factors, such as low socioeconomic status, inadequate social support, neighborhood deprivation, and systemic racism, can greatly shape sleep health and consequently increase CVD risk.
Currently, the ramifications of sleep are far-reaching and underappreciated in the U.S. healthcare systems.[xv] The challenges faced by primary care clinicians in assessing and managing sleep problems for patients include time pressures, high workloads, and a general lack of sleep expertise among providers.[xvi] Therefore, nurses are well-positioned to identify high-risk populations and initiate early intervention to improve patients’ sleep outcomes.
Sleep Assessment Tools
The initial step of sleep assessment is to obtain an accurate, thorough sleep history from patients. This includes assessing sleep/wake schedule, bedtime routine, daytime dysfunction, and potential causes.[xvii] Several instruments are available to assist nurses with understanding patients’ sleep patterns and the severity of sleep problems. The Pittsburgh Sleep Quality Index ([PSQI], 19 items),[xviii] Insomnia Severity Index ([ISI], 7 items),[xix] Epworth Sleepiness Scale ([ESS], 8 items),[xx] and sleep diaries have been widely used to measure individuals’ subjective sleep characteristics.
Objective measures (e.g., polysomnography and actigraphy) are more frequently used for the diagnosis of sleep disorders. Polysomnography or sleep study consists of a simultaneous recording of several physiologic parameters related to sleep and wakefulness.[xxi] This non-invasive technique is the gold standard for diagnosing OSA and other sleep disorders. Actigraphy captures and records movements continuously over an extended period. The wrist-size device is useful in the estimation of total sleep time, sleep efficiency, sleep onset, wake after sleep onset, and the number of awakenings.
Linking sleep and cardiovascular health expands beyond the healthcare setting. With the rapid advances in health technologies, patients can track their sleep and promote sleep knowledge and hygiene through various self-monitoring tools—for instance, smartwatches such as Fitbit,[xxii] and mobile health applications.
Sleep Management Strategies
A growing number of studies have suggested that improving sleep quality may modify the risk of CVD. Even though sleep medications are readily accessible and effective in the short term, current evidence suggests using non-pharmacological approaches as the first-line treatment to manage poor sleep.[xxiii] It is essential that nurses identify the underlying cause of poor sleep and develop targeted interventions that consider the patients’ social context.
Examples of sleep management strategies include:
- Provide sleep hygiene education
- Establish and adhere to a regular sleep-wake schedule
- Limit the duration and frequency of daytime naps
- Maintain regular exercise
- Avoid caffeine, alcohol, heavy meals, and exercise before bedtime
- Establish a comfortable sleep environment, such as eliminating environmental noise and reducing nocturnal light exposure
- Use stress-reduction techniques, such as massage, acupuncture, music, and natural sounds
- Implement cognitive behavioral therapy for insomnia (CBTI), as appropriate.
Nurses play a critical role in assessing and delivering patient-centered care in clinical practice. Emerging evidence has shown positive outcomes from nurse-led sleep interventions, such as CBTI. CBTI is a first-line treatment of chronic insomnia that includes changing behavioral patterns as well as addressing dysfunctional thoughts about sleep.[xxiv] Integrating the essential components of CBTI while addressing social determinants unique to each individual could be a potential approach to improve sleep outcomes. More importantly, improving knowledge and skills of sleep promotion will allow nurses to take initiative and provide high-quality care for patients with poor sleep, thereby forestalling CVD development.
[ii] Wolk R, Gami AS, Garcia-Touchard A, Somers VK. Sleep and cardiovascular disease. Curr Probl Cardiol. 2005;30(12):625-662. doi:10.1016/j.cpcardiol.2005.07.002
[iii] Lloyd-Jones DM, Allen NB, Anderson CAM, et al. Life’s Essential 8: Updating and Enhancing the American Heart Association’s Construct of Cardiovascular Health: A Presidential Advisory From the American Heart Association. Circulation. 2022;146(5):e18-e43. doi:10.1161/CIR.0000000000001078
[iv] Watson NF, Badr MS, Belenky G, et al. Recommended Amount of Sleep for a Healthy Adult: A Joint Consensus Statement of the American Academy of Sleep Medicine and Sleep Research Society. Sleep. 2015;38(6):843-844. doi:10.5665/sleep.4716
[vi] Hale L, Troxel W, Buysse DJ. Sleep Health: An Opportunity for Public Health to Address Health Equity. Annu Rev Public Health. 2020;41:81-99. doi:10.1146/annurev-publhealth-040119-094412
[vii] Jackson CL, Redline S, Emmons KM. Sleep as a Potential Fundamental Contributor to Disparities in Cardiovascular Health. Annual Review of Public Health. 2015;36(1):417-440. doi:10.1146/annurev-publhealth-031914-122838
[viii] Beaman A, Bhide MC, McHill AW, Thosar SS. Biological pathways underlying the association between habitual long-sleep and elevated cardiovascular risk in adults. Sleep Med. 2021;78:135-140. doi:10.1016/j.sleep.2020.12.011
[ix] Hall MH, Brindle RC, Buysse DJ. Sleep and Cardiovascular Disease: Emerging Opportunities for Psychology. Am Psychol. 2018;73(8):994-1006. doi:10.1037/amp0000362
[x]Yeghiazarians Y, Jneid H, Tietjens JR, et al. Obstructive Sleep Apnea and Cardiovascular Disease: A Scientific Statement From the American Heart Association. Circulation. 2021;144(3):e56-e67. doi:10.1161/CIR.0000000000000988
[xi] Park M, Martyn-Nemeth P, Hayman LL. Sleep and Cardiovascular Disease. Journal of Cardiovascular Nursing. 2022;37(1):3-4. doi:10.1097/JCN.0000000000000870
[xii] Grander MA. Addressing sleep disturbances: An opportunity to prevent cardiometabolic disease? Int Rev Psychiatry. 2014;26(2):155-176. doi:10.3109/09540261.2014.911148
[xiii] Curtis DS, Fuller-Rowell TE, El-Sheikh M, Carnethon MR, Ryff CD. Habitual sleep as a contributor to racial differences in cardiometabolic risk. Proc Natl Acad Sci U S A. 2017;114(33):8889-8894. doi:10.1073/pnas.1618167114
[xiv] Grandner MA. Chapter 5 – Social-ecological model of sleep health. In: Grandner MA, ed. Sleep and Health. Academic Press; 2019:45-53. doi:10.1016/B978-0-12-815373-4.00005-8
[xv]Institute of Medicine (US) Committee on Sleep Medicine and Research. Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem. (Colten HR, Altevogt BM, eds.). National Academies Press (US); 2006. Accessed February 27, 2022. http://www.ncbi.nlm.nih.gov/books/NBK19960/
[xvi] Ogeil RP, Chakraborty SP, Young AC, Lubman DI. Clinician and patient barriers to the recognition of insomnia in family practice: a narrative summary of reported literature analysed using the theoretical domains framework. BMC Fam Pract. 2020;21:1. doi:10.1186/s12875-019-1070-0
[xvii] Krystal AD, Prather AA, Ashbrook LH. The assessment and management of insomnia: an update. World Psychiatry. 2019;18(3):337-352. doi:10.1002/wps.20674
[xviii] Buysse DJ, Reynolds CF, Monk TH, Berman SR, Kupfer DJ. The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research. Psychiatry Res. 1989;28(2):193-213.
[xix] Bastien CH, Vallières A, Morin CM. Validation of the Insomnia Severity Index as an outcome measure for insomnia research. Sleep Medicine. 2001;2(4):297-307. doi:10.1016/S1389-9457(00)00065-4
[xx] Johns MW. A New Method for Measuring Daytime Sleepiness: The Epworth Sleepiness Scale. Sleep. 1991;14(6):540-545. doi:10.1093/sleep/14.6.540
[xxi] Gerstenslager B, Slowik JM. Sleep Study. StatPearls Publishing; 2021. Accessed May 25, 2022. https://www.ncbi.nlm.nih.gov/books/NBK563147/
[xxii] Fitbit Technology. Accessed August 4, 2022. https://www.fitbit.com/global/us/technology/sleep
[xxiii] Siebern AT, Suh S, Nowakowski S. Non-Pharmacological Treatment of Insomnia. Neurotherapeutics. 2012;9(4):717-727. doi:10.1007/s13311-012-0142-9
[xxiv] Rossman J. Cognitive-Behavioral Therapy for Insomnia: An Effective and Underutilized Treatment for Insomnia. American Journal of Lifestyle Medicine. 2019;13(6):544-547. doi:10.1177/1559827619867677