The Sleep Apnea Cardiology Connection
Obstructive sleep apnea is a common sleep health condition characterized by breathing that starts and stops intermittently throughout the night. People who suffer from sleep apnea experience daytime sleepiness, overall fatigue, and a lack of mental clarity. It is estimated that over 30 million Americans have OSA, with over 1 billion suffering globally. These staggering statistics are equaled only by the fact that up to 80% of those with the disease go undiagnosed. Sleep apnea goes beyond being just a disease characterized by snoring. Instead, it poses serious comorbidities such as hypertension, stroke, diabetes, and several others associated with cardiovascular health.
What Happens During an Apnea Event?
To fully understand the correlation between heart health and sleep-disordered breathing, it is first essential to learn what the body goes through during an apnea event. The first stage of sleep apnea occurs when the tongue and the muscles surrounding the upper airway relax and collapse, obstructing airflow to the lungs. When breathing stops, blood oxygen levels also drop. Our bodies respond by releasing the stress hormone epinephrine, more commonly known as adrenaline. This “fight or flight” response elevates the heart rate and can lead to high blood pressure. Because the heart becomes less efficient at pumping blood, overall heart function decreases.
The heart itself is affected because of the pressure changes taking place in the chest. The National Institute of Health reports that OSA increases the risk of heart failure by 140%, the risk of stroke by 60% and the risk of coronary heart disease by 30%.
AFib: The Most Common Heart Irregularity
The most common irregular heartbeat or arrhythmia type is Atrial Fibrillation or AFib. According to the Centers for Disease Control and Prevention, AFib affects nearly 6 million people in the US, and it is estimated that 12 million people will have AFib by 2030.
Typically the upper chambers of the heart (atria) and the lower chambers (ventricles) work together to pump blood throughout the body. With AFib, there is a change in the electrical signaling, which directs the heart to beat, resulting in the heart beating faster or slower than normal. As a result, blood pools in the atria, increasing the chance of blood clots and stroke.
The risk factors for developing atrial fibrillation include being over 60, having high blood pressure, diabetes or coronary heart disease and more recently discovered, having sleep apnea.
Shared Risk Factors
The American Heart Association journal Circulation published a review of studies discussing the high prevalence of cardiac comorbidities in patients with obstructive sleep apnea and conversely, the high prevalence of sleep apnea in cardiac patients. While sleep disorders have been linked to a higher risk of cardiovascular disease, common risk factors between the two conditions make the relationship bi-directional.
Obesity is the most common risk factor for sleep apnea and a leading risk factor for heart disease, poor diet, and lack of physical activity. Common sleep apnea comorbidities include high blood pressure and diabetes, also considered risk factors for cardiovascular disease. Because so many patients with cardiovascular disease also suffer from sleep apnea, it makes sense that treatment should be a collaborative effort between sleep medicine practitioners and cardiologists. While this seems like a logical next step, sleep medicine has not been well integrated into various practice areas.
Without sleep medicine being an active part of their practice, Cardiologists risk losing their patients to a sleep medicine system that is not well-coordinated nor working in partnership with the common goal of better patient outcomes. It is no wonder that patients continue to go undiagnosed for sleep apnea when there is not a coordinated effort between their doctors to work together.
Can You Treat Coexisting Heart Disease and Sleep Apnea?
Obesity is a common thread in sleep apnea and cardiovascular diseases, but they can independently increase the risk for various heart conditions. Lifestyle changes such as losing weight and becoming physically more active are suitable for the heart and lessening sleep apnea symptoms. The gold standard in sleep apnea treatment is Continuous Positive Airway Pressure or CPAP.
CPAP is often the first course of treatment doctors suggest when a patient is initially diagnosed with moderate to severe sleep apnea. The CPAP machine takes in the room’s air, filters and pressurizes it, and then delivers it through a hose attached to a mask you wear during sleep. The continuous flow of air keeps the soft tissues of the tongue and palate from relaxing and blocking the airway. According to the National Sleep Foundation, CPAP can lower blood pressure over time. By eliminating fragmented sleep, there is less pressure on the heart and the erratic heartbeats associated with AFib can also be reduced.
Sleeps Role in Overall Health
The importance of sleep on overall health can’t be underestimated. One of the important functions of sleep is to allow the body to rest and repair. Deep sleep is restorative and allows your body to replenish energy and repair cells. Chronic sleep deprivation has been linked to elevated blood pressure and increased risk of heart attacks, diabetes and stroke.
Some of the most recent studies on sleep and heart health from Columbia University find that consistent sleep plays a vital role in heart health and overall health. And a lack of sleep causes many other physiological changes, including hormonal changes that increase our food cravings, once again leading to obesity which is at the center of sleep apnea as well as many heart conditions.
If you have sleep apnea symptoms, it is crucial to get tested, especially if you already have heart disease or high blood pressure. While medications can help control heart disease, and CPAP can ease sleep apnea symptoms, the best advice might be to eat a well-balanced diet, exercise regularly, and ensure you have good, consistent sleep.