Q&A on Narcolepsy and Heart Health, with Dr. Bogan, MD

Richard K. Bogan, MD, FCCP, FAASM

A good night’s rest is an important piece of cardiovascular (CV) health. But for the nearly one in 2,000 people in the United States living with narcolepsy, sleep is just one of the issues that affect the health of their hearts.¹ In fact, research shows that narcolepsy patients have an increased prevalence of developing high blood pressure, cardiovascular disease, and diabetes.²

And while a connection between narcolepsy and heart health has been established, new findings are helping healthcare providers better understand how to manage patients with narcolepsy in various aspects, including sodium intake. For Heart Month, Dr. Bogan took part in a Q&A to discuss the importance of heart health in narcolepsy and shed light on some of the recent developments that are helping both patients and doctors make more informed decisions about this condition.

For those who are unfamiliar, what is narcolepsy?

Narcolepsy is a chronic, debilitating neurological disorder characterized by excessive daytime sleepiness (EDS) and the inability to regulate sleep-wake cycles normally.³ The primary symptoms of narcolepsy include EDS, cataplexy, disrupted nighttime sleep, sleep-related hallucinations, and sleep paralysis.These symptoms can have a devasting impact on people living with narcolepsy and unplanned lapses into sleep can affect daily activities like driving, eating, or talking.⁴

How does narcolepsy affect the heart?

Any sleep interruption has an impact on heart health. When people sleep, our blood pressure lowers naturally, which is known as nocturnal dipping. Studies have shown that non-dipping nocturnal blood pressure is associated with increased cardiovascular risk and is prevalent in people with narcolepsy. In addition, the blunted nocturnal blood pressure dipping observed in people with narcolepsy was associated with sleep fragmentations and arousals.⁵ Additionally, narcolepsy patients are at an increased risk of developing hypertension and cardiovascular disease.^2,6,7,8 Further, mood disturbances including depression and anxiety often affect patients with narcolepsy and research has shown that people experiencing depressive and anxiety disorders may experience certain effects on the body.^9,10 This includes increased cardiac reactivity (e.g., increased heart rate and blood pressure), reduced blood flow to the heart, and heightened levels of cortisol.¹⁰ Thus, there are a series of issues that affect the heart health of narcolepsy patients and create greater health challenges.

How important is the role of cardiology in helping to manage narcolepsy patients’ heart health?

Cardiology has a major role in helping narcolepsy patients because of the way their condition specifically affects heart health. Narcolepsy patients have to be very cognizant of the amount of sodium they consume in their diet as well as the medications they take, as some medications when taken on a daily, consistent basis can result in a higher sodium intake.^11,12 The impact of excessive sodium consumption on heart health is well established and there is more that can be done to help narcolepsy patients understand their risk factors. This is where cardiologists come in: they can help lead discussions with their patients on the impact of high sodium intake on long-term health as well as the types of treatment options that can affect the sodium intake of these patients.

Does medication play a role in affecting narcolepsy patients’ hearts?

Although food and beverages are common sources of sodium consumption, some medications, including one used to treat narcolepsy, can also have high levels of sodium, which can play a role in affecting the heart health of narcolepsy patients.^11,12 This is why it’s important for cardiologists to understand how medications might affect their patients' heart health and encourage them to make healthy lifestyle choices including eating a healthy diet and reducing sodium intake levels.¹³ Researchers have estimated that reducing sodium by a half teaspoon a day could prevent up to 120,000 new cases of coronary heart disease, 66,000 strokes, and 99,000 heart attacks, so taking this one step could make a significant difference in lowering risks among narcolepsy patients.¹⁴

What should cardiologists be talking about with their patients living with narcolepsy?

First and foremost, cardiologists should be talking about comorbidities, especially if their patient hasn’t developed any yet. Research has showed that inadequate sleep triggers a part of the brain that plays a role in hunger and appetite, which may cause obesity in narcolepsy patients, as individuals with sleep-wake abnormalities typically have a higher calorie intake.^15,16 Staying ahead of heart disease, working to prevent diabetes, and keeping track of high blood pressure should all be a priority at any stage of a patient’s journey. If we can protect a patient’s heart through education and conversation, it goes a long way in preventing further damage to their overall health. Cardiologists should be mindful of the CV risks their narcolepsy patients face, any existing comorbidities they may have and their underlying cardiovascular status to understand the best approach for those who need it the most.

References

1. Ahmed I, Thorpy, M. Clinical Features, Diagnosis and Treatment of Narcolepsy. Clin Chest Med. 2010;31(2):371-381.
2. Black J, Reaven NL, Funk SE, et al. Medical comorbidity in narcolepsy: findings from the Burden of Narcolepsy Disease (BOND) study. Sleep Med. 2017;33:13-18. doi:10.1016/j.sleep.2016.04.004
3. Thorpy M, Krieger A. Delayed diagnosis of narcolepsy: characterization and impact. Sleep Med. 2014;15(5):502–507.
4. National Institute of Neurological Disorders and Stroke. Narcolepsy Fact Sheet. https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Narcolepsy-Fact-Sheet. Accessed January 2022.
5. Dauvilliers Y, Jaussent I, Krams B, et al. Non-dipping blood pressure profile in narcolepsy with cataplexy. PLoS One. 2012;7(6):e38977. doi:10.1371/journal.pone.0038977
6. Ohayon MM. Narcolepsy is complicated by high medical and psychiatric comorbidities: a comparison with the general population. Sleep Med. 2013;14(6):488-492. Doi:10.1016/j.sleep.2013.03.002
7. Cohen A, Mandrekar J, St Louis EK, Silber MH, Kotagal S. Comorbidities in a community sample of narcolepsy. Sleep Med. 2018;43:14-18. Doi:10.1016/j.sleep.2017.11.1125
8. Jennum P, Ibsen R, Knudsen S, Kjellberg J. Comorbidity and mortality of narcolepsy: a controlled retro- and prospective national study. Sleep. 2013;36(6):835-840. Published 2013 Jun Doi:10.5665/sleep.2706
9. Ruoff CM, Reaven NL, Funk SE, et al. High Rates of Psychiatric Comorbidity in Narcolepsy: Findings From the Burden of Narcolepsy Disease (BOND) Study of 9,312 Patients in the United States. J Clin Psychiatry. 2017;78(2):171-176. doi:10.4088/JCP.15m10262
10. Centers for Disease Control and Prevention. Heart Disease and Mental Health Disorders. https://www.cdc.gov/heartdisease/mentalhealth.htm#:~:text=People%20experiencing%20depression%2C%20anxiety%2C%20stress,and%20heightened%20levels%20of%20cortisol. Accessed January 2022.
11. Perrin G, Korb-Savoldelli V, Karras A, Danchin N, Durieux P, Sabatier B. Cardiovascular risk associated with high sodium-containing drugs: A systematic review. PLoS One. 2017;12(7):e0180634. Published 2017 Jul 6. doi:10.1371/journal.pone.0180634
12. Quader ZS, Zhao L, Gillespie C, et al. Sodium intake among persons aged ≥2 years — United States, 2013–2014. MMWR Morb Mortal Wkly Rep. 2017;66:324–238. DOI: http://dx.doi.org/10.15585/mmwr.mm6612a3
13. Centers for Disease Control and Prevention. Prevent Heart Disease. https://www.cdc.gov/heartdisease/prevention.html. Accessed January 2022.
14. Bibbins-Domingo K, Chertow GM, Coxson PG, et al. Projected effect of dietary salt reductions on future cardiovascular disease. N Engl J Med. 2010;362(7):590‐599.doi:10.1056/NEJMoa0907355
15. Greer SM, Goldstein AN, Walker MP. The impact of sleep deprivation on food desire in the human brain. Nat Commun. 2013;4:2259. doi:10.1038/ncomms3259
16. Chabas D, Foulon C, Gonzalez J, et al. Eating disorder and metabolism in narcoleptic patients. Sleep. 2007;30(10):1267-1273. doi:10.1093/sleep/30.10.1267