Sleep apnea is a sleep disorder that can be life-threatening if left undiagnosed and untreated. Within the United States, up to 18 million people have been diagnosed with sleep apnea; however, it is estimated that up to 4% of Americans have an undiagnosed case of sleep apnea. The two types of sleep apnea include obstructive sleep apnea, affecting 10-30% of American adults, and central sleep apnea, affecting less than 1% of adults. (5, 6)
Sleep apnea is not a benign condition. Due to daytime fatigue and poor concentration, people with sleep apnea are six times more likely to die in a car accident (5). In fact, the National Highway Traffic Safety Administration has estimated that drowsy driving causes 800 fatalities annually. Additionally, sleep apnea is associated with poorer cardiovascular health and obesity and increases the risk of heart failure by 140%.
What is Sleep Apnea?
Sleep apnea is a condition in which breathing stops and restarts during sleep. There are two types of sleep apnea. (1)
Obstructive sleep apnea (OSA) occurs when the upper airway becomes blocked during sleep, reducing or completely stopping airflow. OSA is the most common type of sleep apnea. Obesity, central fat distribution, enlarged tonsils, advanced age, male gender, pregnancy, alcohol use, smoking, and sleeping supine can increase the risk for OSA. (1, 2)
Central sleep apnea (CSA) is less common than OSA and occurs when the brain doesn't send the proper signals to the muscles involved in breathing. Risk factors for CSA include male gender, age over 60, atrial fibrillation, congestive heart failure, brain tumors, brainstem lesions, history of stroke, high altitude, and opioid use. (1, 3)
5-15% of people with OSA develop CSA using their continuous positive airway pressure (CPAP) machine. This is called treatment-emergent CSA, a combination of obstructive and central sleep apneas. Treatment-emergent CSA resolves on its own within the first few months of CPAP treatment in more than 50% of cases. Other patients require a change in treatment therapy. (4)
Sleep Apnea Symptoms
Sleep apnea symptoms include (7, 8):
- Loud snoring
- Fatigue and excessive daytime sleepiness
- Irritability, depression, and anxiety
- Memory loss and trouble concentrating
- Repeat wakings during the night
- Sexual dysfunction
- Waking with a headache and dry mouth
Some sleep apnea symptoms may be harder to identify or may be observed by others. Repeated waking during the night is common, but many people with sleep apnea don't remember doing this or think they've awoken for another reason, like needing to use the bathroom. Loved ones sharing a bed or room with the patient may note that the patient stops breathing, gasps for air, or chokes during the night. (7, 8)
Cheyne-Stokes breathing (CSB) is a distinct breathing pattern of CSA characterized by fast breathing that gets deeper and shallower until breathing stops.
Can You Die From Sleep Apnea?
Research shows that people with OSA have a higher risk of all-cause mortality, meaning they are more likely to die of any cause than those without OSA. The severity of OSA is correlated with the risk of all-cause mortality. Untreated OSA has been linked to an increased risk of death from cardiovascular complications (i.e., abnormal heart rate, high blood pressure, heart attack, stroke, heart disease, type 2 diabetes, pulmonary hypertension), life-threatening postoperative complications, and liver disease. Additionally, daytime sleepiness and lack of concentration make potentially fatal car crashes more likely. (9)
It is uncommon, but people with OSA can die during sleep if they cannot reinitiate breathing during an apneic episode (9). The good news is that treating OSA with a CPAP is associated with a significant decrease in all-cause mortality.
There are fewer studies on CSA and its effect on the risk of death. However, CSA is associated with health problems (e.g., heart failure) that increase the risk of death. (9)
What Causes Sleep Apnea?
OSA occurs when the muscles in the back of the throat, which support the soft palate, uvula, tonsils, throat, and tongue, relax. When these muscles relax, the airway narrows during inhalation, impairing normal breathing. The brain senses lower oxygen levels in the blood, which causes the patient to awaken. There are many risk factors for OSA. Excess weight and obesity, especially when fat deposits around the upper airway, can obstruct breathing. Anatomical variations of the head and neck, including a larger tongue, thicker neck, shorter lower jaw, and enlarged tonsils, can block the airways. (6, 7)
Alcohol, sedatives, and narcotics are associated with an elevated risk of OSA because they can relax the muscles in the throat. Additionally, smoking can cause inflammation and fluid retention in the upper airway, contributing to airway blockages. (6, 7)
Medical conditions, including congestive heart failure, high blood pressure, type 2 diabetes, chronic lung disease, and nasal congestion, are associated with an increased risk of developing OSA. Under active thyroid function (hypothyroidism or subclinical hypothyroidism) and excess growth hormone can lead to higher body mass and swelling of the airway tissues. (6, 7)
CSA most often occurs due to another medical problem affecting the brain stem. Medical conditions associated with CSA include stroke, heart failure, and end-stage kidney disease. The use of opiate medications, including morphine, oxycodone, codeine, and methadone, can also interfere with normal brain signals that control breathing. Lastly, sleeping in high altitudes can contribute to CSA because of decreased oxygen availability. (3, 6)
Functional Medicine Labs to Test for Root Cause of Sleep Apnea
Functional medicine labs help practitioners personalize treatment options for their patients. Below are some of the most common labs ordered for patients suffering from sleep apnea.
Polysomnography, or a sleep study, is the gold standard for diagnosing sleep apnea. It is recommended to refer patients for diagnostic testing for sleep apnea with excessive daytime sleepiness and at least two of the following symptoms: diagnosed hypertension, loud snoring, witnessed apneas, or gasping/choking episodes during sleep. The Epworth Sleepiness Scale and STOP-Bang Questionnaire are validated screening tools that can easily be administered in the primary care setting to evaluate a patient's likelihood of having sleep apnea.
Given that cardiometabolic disease increases the risk for sleep apnea and vice versa, a comprehensive cardiometabolic assessment should be ordered for all patients with diagnosed sleep apnea to assess metabolic function.
A comprehensive metabolic panel (CMP) is an excellent screening tool that includes 14 biomarkers related to metabolic function, including blood glucose and kidney and liver function markers. It can be helpful for patients presenting with vague symptoms like fatigue and weight gain and is part of routine blood work for patients with chronic conditions like diabetes, hypertension, and kidney disease.
In addition to blood glucose on the CMP, fasting insulin and hemoglobin A1c (HbA1c) should be ordered to screen for and monitor insulin resistance, dysglycemia, and diabetes.
An advanced lipid panel measures important biomarkers related to cholesterol levels, lipid composition, and cardiovascular disease risk.
Ruling out hypothyroidism with a thyroid panel is important because underactive thyroid can contribute to weight gain, difficult weight loss, and cardiovascular disease.
Undiagnosed and untreated allergies can exacerbate sleep apnea by contributing to nasal congestion and inflammation/narrowing of the airways. Screening of common food and environmental allergens can be performed through a blood draw.
Food sensitivities can also contribute to allergy-like symptoms and cause low-grade systemic inflammation. Especially for patients with concurrent gastrointestinal symptoms, a food sensitivity panel may be warranted.
Conventional Treatment for Sleep Apnea
The first-line treatment for sleep apnea is continuous positive airway pressure (CPAP), which keeps the airways open. CPAP adherence varies from 17-85%. Other airway pressure devices and oral appliances are available as alternative options for those who cannot tolerate CPAP. In some instances, surgery may be required to correct anatomical obstructions.
Functional Medicine Sleep Apnea Treatment
Functional medicine protocols for sleep apnea also emphasize the use of CPAP, especially for OSA, given that research shows that compared to no treatment, CPAP results in a clinically significant reduction in disease severity, sleepiness, blood pressure, and motor vehicle accidents. In addition, your functional provider will recommend alternative strategies to address the root causes and comorbidities of sleep apnea.
Sleep Apnea Diet and Exercise
Weight loss can reduce fatty deposits in the neck, tongue, and abdomen, which improves airflow and lung volume. Dietary modifications are essential to weight loss; however, despite extensive research studying the efficacy of various nutritional plans, no one diet is superior for every person in facilitating weight loss goals. The Mediterranean and DASH diets have been studied as cardioprotective dietary plans effective in managing weight (11, 12).
Aerobic exercise and strength training mitigate cardiovascular consequences of sleep apnea, including heart disease and glucose intolerance, facilitate weight loss, and improve energy levels. Research shows that patients with OSA who partake in regular, predominantly aerobic, exercise have reduced disease severity and daytime sleepiness. However, physical activity provides additional benefits beyond these. Regular exercise strengthens muscle tone within the upper airway, reduces fluid accumulation in the neck, and has anti-inflammatory effects, improving airway patency. (10)
Alcohol and Sleep Apnea
Many studies have found that alcohol exacerbates sleep apnea, worsens the severity of disease symptoms, and can contribute to adverse cardiovascular outcomes. This meta-analysis demonstrated a 25% increased risk of sleep apnea with higher levels of alcohol consumption.
Alcohol raises a person's arousal threshold, making it more challenging to wake up and restart breathing during an apneic episode. Alcohol can also increase nasal congestion and induce relaxation of the mouth and throat muscles, worsening OSA. (13)
Supplements for Sleep Apnea
There are limited human studies that investigate nutraceutical therapies for treating sleep apnea, but those that are available support antioxidant and cardiovascular-specific supplements and warrant continued examination of their use in treating sleep apnea.
NAC given orally three times for one month improves apnea severity, oxygen saturation, daytime sleepiness, and snoring.
Vitamins C and E
Studies that have administered antioxidant cocktails containing vitamins C and E found improved markers of cardiovascular oxidative stress, endothelial function of blood vessels, daytime sleepiness, and sleep quality. In addition, patients taking vitamins C and E have reductions in apneic episodes and can reduce the pressure settings of their CPAP machines. (14-16)
Coenzyme Q10 (CoQ10)
CoQ10 is best known for its beneficial effects on the cardiovascular system and metabolism due to its involvement in mitochondrial energy production. CoQ10 administered with vitamins C and E improved respiratory function in men with OSA (16). CoQ10 should be considered in patients with sleep apnea who are at risk of or have been diagnosed with cardiovascular comorbidities, including hypertension and diabetes.
Lower vitamin D status has been noted in patients with OSA compared to healthy controls. Low vitamin D status is associated with an increased risk for insulin resistance, diabetes, and metabolic syndrome in patients with OSA (17, 18). A small study concluded that supplementing vitamin D at 4,000 IU daily improved metabolic biomarkers hs-CRP, Lp-LPA2, lipids, and fasting glucose.
Complementary and Alternative Medicine for Sleep Apnea
In addition to lifestyle modifications and nutraceutical supplementation to promote weight loss and reduce inflammation, functional practitioners may refer you to a functional dentist, speech therapist, or chiropractor for additional evaluation of the mouth and cervical spine to get to the root cause of airway issues contributing to OSA.
Additional modalities used to treat sleep apnea may include allergen immunotherapy (AIT) to induce tolerance of allergens contributing to nasal congestion, positional therapy that prevents back-sleeping during the night, and soft palette-strengthening exercises.
Sleep apnea is a sleep disorder related to physical obstruction of the airways or a lack of brain communication that impairs breathing during sleep, causing snoring and daytime sleepiness. Undiagnosed sleep apnea can increase the risk of chronic medical conditions and, in severe cases, death. Medical interventions, like a CPAP machine, are often required and effective in treating sleep apnea. A functional medicine approach to sleep apnea also appreciates the utility of incorporating alternative strategies into the treatment protocol to maintain a healthy weight and support cardiovascular health.
Lab Tests in This Article
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