Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) are two conditions found commonly in the adult population. They’re one of the conditions that physicians at a sleep disorder center in Riverview, Michigan commonly deal with. Both COPD and OSA plague a person’s breathing and sleep capability to a significant extent. However, when they coexist, they manifest even more pronounced health concerns. This association is known as the overlap syndrome and is our topic of interest in this article.
Here, we will address this condition’s pathophysiology, scope, and clinical presentation. In addition, we’ll also compare the effect of OSA and Chronic obstructive pulmonary disease singularly and together as the overlap syndrome. Finally. we’ll conclude the article with the management and treatment options the physicians are leveraging for this association.
Before we begin with the overlap syndrome, we’ll look into COPD and OSA, along with their interaction with sleep physiology.
Chronic Obstructive Pulmonary Disease
COPD or chronic obstructive pulmonary disease is an inflammatory lung condition. It is characterized by obstructed airflow that compromises breathing. COPD is an umbrella term that includes various diseases such as emphysema and chronic bronchitis. In emphysema, the lung tissue is damaged whereas the latter is characterized by a consistent, mucus-producing cough.
Chronic obstructive pulmonary disease plagues more than 15 million Americans and is the third most common cause of disease-related deaths. Even more so, COPD is responsible for one death every four minutes, a fact that speaks for its seriousness. However, in addition to causing shortness of breath, wheezing, and persistent cough, COPD also affects sleep.
Sleep and COPD: How Do They Affect Each Other?
It is common for people suffering from chronic obstructive pulmonary disease (COPD) to experience trouble falling or staying asleep. It affects sleep quality and duration through various physiological mechanisms. For instance, sleep in COPD is commonly impaired through oxygen desaturation, i.e. decreased percentage of oxygen in the blood. The extent of oxygen desaturation here is even greater than the degree of desaturation during physical exertion and hence renders a person significantly out of breath.
Various mechanisms contribute to the onset of oxygen desaturation and consequently sleep trouble. It can be due to hypoventilation, in which breathing is too shallow to meet the body’s requirements. Another factor is a ventilation-perfusion mismatch, i.e. when the lung or some of its parts may receive blood without oxygen or oxygen without blood flow. Moreover, in severe cases, the breathing irregularities are not just nocturnal but may persist during the day as well. In such cases, a person may experience daytime hypoxemia which might be related to much more pronounced episodes during the night. To help you understand better, hypoxemia is a condition in which the blood contains unusual concentrations of oxygen.
On the other hand, sleep also influences breathing patterns in a variety of ways. When you sleep, there’re certain changes in central respiratory control, lung mechanics, and muscle contractility. These insignificant changes can have a greater adverse impact if COPD exists. Now, the same mechanism can lead to hypoxemia and hypercapnia (unusually high concentration of carbon dioxide in the blood), especially during REM sleep.
How Common Are Sleep Disorders in People with COPD?
One of the most common symptoms that are reported by Chronic obstructive pulmonary disease (COPD) patients is sleep trouble. Moreover, a study shows that around 40% of COPD patients complained of sleep disturbance. This irregularity can be classified as difficulty in falling or remaining asleep, having light sleep, or decreased REM sleep. In addition, such patients may also experience frequent changes in sleep stages as well as micro-arousals.
In COPD, another factor that plays a vital role in impairing sleep is a breathing-related disorder known as obstructive sleep apnea (OSA). It is usually associated with COPD as a condition that frequently appears and causes a person to experience consistent nocturnal awakening.
In OSA, the upper airway is blocked repetitively at night due to the frequent relaxation of muscles that support the tongue and soft palate. As a result, the airway narrows or even closes, leading to a temporary and short-lived interruption in breathing. It is one of the most common sleep disorders and is more prevalent in men and postmenopausal women. Being a prevalent condition, it is not very difficult to diagnose OSA. One of its most prominent signs includes snoring, gasping for air, and choking.
Coexistence of Sleep Disorders and COPD: The Overlap Syndrome
Both COPD and OSA are prevalent in the general population. However, When the two conditions exist simultaneously, they increase the enhanced risk of increased morbidity and mortality. This coexisting of COPD and OSA in a patient is known to be an overlap syndrome. Its prevalence is known to be 1% of the human population.
What sets overlap syndrome apart from Chronic obstructive pulmonary disease (COPD) and OSA is the severity of its symptoms. Overlap patients experience much more pronounced sleep-related hypoxemia and hypercapnia than patients with just COPD or OSA. The same is the case with oxygen desaturation which is also much more severe when the two diseases coexist. Furthermore, the changes in respiratory physiology during sleep also increase in severity in overlapped patients. The adverse effects that were once negligible are now prominent as COPD and OSA coexist. They now increase greater the risk of cardiovascular diseases, acute COPD aggravation, as well as hospitalization.
The diagnosis, treatment, and patient outcome of overlap syndrome are of great clinical importance. The syndrome presents a greater risk of morbidity and mortality rate as compared to the rate of the two diseases alone. However, it is now that the clinicians are keen to understand the interaction and existence of COPD and OSA together and to determine remedial strategies for it. Today, the medical field is vigilantly evaluating the definition, prognosis, and ideal treatment for overlap syndrome.
What are Some Signs That Indicate Overlap Syndrome
To begin with the treatment of overlap syndrome, clinicians should assess the patient for the symptoms of OSA and COPD. Patients who are more likely to be diagnosed with Chronic obstructive pulmonary disease (COPD) will report deteriorated sleep quality and daytime fatigue. On the other hand, patients suffering from OSA will complain of snoring, excessive daytime sleepiness, and drowsiness.
In addition to these distinct signs, the co-existence of OSA and COPD is also manifested as:
Increased chances of exacerbation.
- Greater mortality rate.
- Nocturnal oxygen desaturation persists for a long time.
- Poor quality of life.
- Increased chances of nocturnal mortality rates.
When both COPD and OSA exist simultaneously, the symptoms of OSA are as follows:
pulmonary hypertension
- hypercapnia
- fatigue
- Frequent urination
- Coughing
Diagnosing Overlap Syndrome: is it the Same or is it Different?
Since the symptoms of the overlap syndrome are the same as COPD and OSA, so are their diagnostic approach. Polysomnography which is the gold standard for diagnosing OSA holds similar importance for OS. In addition, physicians also leverage overnight oximetry as a screening test for diagnosing nocturnal hypoxia during sleep. If the oximetry test reveals a cyclical (sawtooth) pattern, it is an indication of sleep apnea in a COPD patient. As a result, the physicians then confirm the diagnosis through polysomnographic studies.
However, according to Sleep Heart Health, patients with mild COPD might not necessarily present the typical symptoms of OSA. In such cases, the patients may not complain of poor quality of sleep. Nonetheless, the physician should rule out sleep apnea, only after performing polysomnography.
Can You Sleep Well Despite This Syndrome?
Yes, you can. Physicians have now derived adequate treatments for overlap syndrome that helps you and others sleep well at night. If you think that the treatment strategy for OS would mimic that of Chronic obstructive pulmonary disease (COPD) and OSA, you are not wrong. In fact, the mainstay of OS treatment is to ensure consistent COPD
management ad continuous positive airway pressure ventilation (CPAP). CPAP is a device that patient uses during sleep to prevent their oxygen level from dropping. The CPAP device delivers a stream of air at a uniform pressure that prevents the airway from collapsing. As a result, the patient does not experience hindrance in breathing. CPAP holds great importance in maintaining the patient’s REM sleep phase during which the muscles of the airways are most likely to collapse.
However, in addition to CPAP, there are other treatment approaches that may manage OS, such as:
Losing weight: Obesity plays an important role in OSA and both Chronic obstructive pulmonary disease (COPD). So much so, that in the latter condition, obesity is known to increase the mortality rate. While no data prove weight loss is a therapeutic strategy, the physician believes that the approach can offer symptomatic relief.
Supplemental Oxygen:
It is a viable strategy if and when the patient experiences both daytime and nocturnal hypoxemia. Furthermore, various studies prove that when delivered for more than 18 hours per day, supplemental oxygen can also improve the disease’s mortality.
Medications:
Bronchodilators and Corticosteroids play a helpful role in treating underlying lung diseases such as Chronic obstructive pulmonary disease (COPD). Oral steroid therapy has shown satisfactory results in improving nocturnal oxygen desaturation and total sleep duration.
Sleep Well, Live Well..!
Overlap syndrome can be a tricky condition to live with, provided it’s a combination of two serious diseases. However, a timely visit to a certified lung and sleep specialist in Michigan can help with adequate management. Book an appointment today to have better control over your breathing, and ultimately your life.
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