COPD and Sleep Apnea Overlap (COPD and Sleep Apnea)

What is COPD and Sleep Apnea Overlap (COPD and Sleep Apnea)?

The term “overlap syndrome” was first initiated by David C. Flenely in 1985 and describes the connection between obstructive sleep apnea (OSA) and breathing disorders such as chronic obstructive pulmonary disease (COPD). COPD refers to continuous breathing difficulties and unalterable limitations on the airflow in the lungs. People suffering from COPD often face difficulties in falling asleep and constantly wake up at night, which results in poor sleep and extreme tiredness throughout the day.

At night, problems like low oxygen levels and inadequate ventilation generally occur during the phase of sleep where your eyes move rapidly (REM sleep) for people affected by COPD. These issues arise from decreased chest movement and the relaxation of the muscles between the ribs. Conversely, patients with OSA frequently wake up during the night and experience excessive sleepiness during the day because of a blocked airway, decreased pressure within the chest, and an overactive nervous system.

Overlap syndrome patients show more prominent drops in nighttime oxygen levels than those suffering from either COPD or OSA alone, increasing their risk for heart-related issues like pulmonary hypertension, right heart failure, and irregular heart rhythms. The joint occurrence of COPD and OSA complicates both diagnosis and treatment. Given the increased health risks and potential life-threatening conditions connected with overlap syndrome, healthcare workers need to be aware of this condition for timely diagnosis and treatment.

With the increased numbers of COPD and OSA, research shows that 1 in 10 people with either condition might also have the other one, purely by chance. Yet, it is debated whether people with COPD are more likely to have OSA than people without COPD, as some studies show no difference. However, other research has identified a high rate of OSA in COPD patients with moderate to severe conditions that were referred to lung rehabilitation.

What Causes COPD and Sleep Apnea Overlap (COPD and Sleep Apnea)?

Research suggests a two-way relationship between Chronic Obstructive Pulmonary Disease (COPD) and Obstructive Sleep Apnea (OSA). This means that some people with COPD might later start suffering from OSA and vice versa. Factors such as being older, being male, smoking, alcohol intake, and a lack of physical activity can all contribute to the development of this condition.

Smoking is a widely recognized risk factor for both COPD and OSA. This is because it speeds up the worsening of the diseases by causing stress to the body’s cells, releasing inflammation-inducing substances, which in turn cause inflammation in the upper airway and increase the likelihood of OSA. Furthermore, obesity, particularly having a larger neck size, can significantly raise the chances of having OSA, as it may lead to a narrower upper airway, resulting in lower oxygen levels during sleep.

Other risk factors for OSA may include having a smaller lower or upper jaw, thyroid disorder, excessive growth hormone, being male, being between ages 40-65, and certain genetic conditions like myotonic dystrophy and Ehlers-Danlos syndrome.

COPD covers a range of airway diseases, including emphysema, chronic bronchitis, and chronic obstructive asthma. The possibility of developing OSA varies depending on the type of COPD. For instance, patients with emphysema often have over-inflated lungs and lower body weight due to difficulty breathing and increased effort to breathe, especially in the later stages of COPD. On the other hand, those with chronic bronchitis frequently have a higher body weight, which can increase their risk of developing OSA, especially if they have a lot of fat tissue around their neck. In developing countries, exposure to certain job or environmental conditions can significantly contribute to COPD onset and progression.

Risk Factors and Frequency for COPD and Sleep Apnea Overlap (COPD and Sleep Apnea)

COPD and OSA are among the most common lung diseases worldwide, but they don’t always occur together. Research says that about 1 in 10 people diagnosed with either of these conditions may also have the other. In the general and hospital populations, the rate of both diseases existing together ranges from 1.0% to 3.6%.

COPD is a major health problem. It is the third most common cause of death in the world, leading to 3.23 million deaths in 2019. Around 55% of the people living with chronic respiratory disease in 2017 had COPD. Overall, about 10% of the world’s population has COPD. Most of these cases are linked to smoking (70% in high-income countries, 30% in low- and middle-income countries), while indoor air pollution is another major risk factor in low- and middle-income countries.

On the other hand, about 30% of people in the U.S suffer from OSA, which affects an estimated 1 billion people globally. Among adults aged 30 to 60, the rate of OSA is 24% for men and 9% for women. The increasing rates of obesity have largely contributed to the growing number of OSA cases.

Data on the prevalence of patients with both COPD and OSA (also known as overlap syndrome) is still under review. A review of studies shows a significant range in prevalence rates, making it difficult to accurately calculate the true incidence. For those primarily diagnosed with COPD, between 2.9% and 65.9% also have OSA. Among those primarily diagnosed with OSA, the incidence of COPD varies between 7.6% and 55.7%. In older patients with COPD and those on long-term oxygen therapy, overlap syndrome rates are 21.4% and 15.7%, respectively.

However, accurately determining the number of people with overlap syndrome is challenging due to several factors:

• Varying definitions and diagnostic criteria for COPD and OSA
• Missing a COPD or OSA diagnosis when the other has been established
• No standard definition or specific diagnostic code for overlap syndrome
• Updated criteria to categorize nighttime breathing issues
• Difficulty defining and including additional breathing-related issues like low oxygen levels, arousal related to breathing, and disturbances in the body’s automatic functions
• Study selection bias caused by small convenient samples or diverse groups
• Differences in results from at-home and traditional overnight sleep studies
• Varying definitions of what constitutes sleep apnea
• Effects of long-term oxygen therapy on sleep study results
• Cost of overnight sleep studies

Signs and Symptoms of COPD and Sleep Apnea Overlap (COPD and Sleep Apnea)

Overlap syndrome is a medical condition that displays symptoms of both chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA). People suffering from this condition often experience:

• Obesity
• Increased neck size
• Excessive sleepiness during the day
• Disruptions in sleep
• High blood pressure

People with COPD usually have symptoms of:

• Producing a lot of mucus (sputum)
• Shortness of breath
• Coughing
• Wheezing sounds when breathing
• Forgetfulness and confusion
• Disrupted sleep, possibly due to breathing issues

On the other hand, people with OSA often experience:

• Excessive sleepiness during the day
• Loud snoring
• Gasping for air while asleep
• Needing to urinate frequently at night (nocturia)
• Headaches in the morning
• Choking during sleep

Quite often, their snoring and pauses in breathing are noticed by their sleeping partner.

People with overlap syndrome (COPD and OSA) can also face more complications that include:

• Decreased oxygen levels in the blood (hypoxemia)
• Increased carbon dioxide levels in the blood (hypercapnia)
• High blood pressure in the blood vessels carrying blood to the lungs (pulmonary hypertension)

They may also struggle with headaches in the morning due to hypercapnia, bluish skin color from hypoxemia, and swelling in the hands and feet due to heart strain related to lung disease (cor pulmonale).

Testing for COPD and Sleep Apnea Overlap (COPD and Sleep Apnea)

There are no established guidelines for screening COPD patients for OSA. But, experts suggest using the STOP-Bang questionnaire that looks at snoring, tiredness, observed sleep apnea, blood pressure, body mass, age, neck size, and gender. Patients with a score between 5 and 8 are at high risk for moderate to severe OSA while those scoring between 0 and 2 are at low risk. For those with a score of 3 or 4, a closer look at the patient’s overall health is needed.

Patient with COPD, pulmonary hypertension, and low or unstable oxygen levels during sleep may need a sleep study. Those with even mild COPD and signs of high blood pressure in the lung vessels might require a sleep test. There are other questionnaires also available that look for potential OSA patients including the NoSAS and Berlin questionnaires.

Patients suffering from both OSA and COPD demonstrate higher scores on several medical assessments, but not all patients with these conditions experience excessive sleepiness, but may report fatigue which is slightly different and can create inaccuracies in questionnaire results.

Polysomnography is the gold standard for detecting sleep disturbances, but overnight oximetry, which measures oxygen levels in the blood, can also help identify hypoxia (lowered oxygen levels than normal) during sleep and suggest a likelihood of OSA in COPD patients. However, it is necessary to confirm this with overnight polysomnography.

The severity of OSA is calculated using the Apnea-Hypopnea Index (AHI) and Respiratory Disturbance Index (RDI), which calculate the number of sleep disruptions per hour. A number above 30 events per hour is categorized as severe.

Though some patients may opt for a home sleep apnea test, it is not generally recommended for people with severe lung disease due to its limitations, such as its inability to detect low oxygen levels resulting from inefficient breathing. Overestimating oxygen levels can result in the wrong treatment being prescribed.

To diagnose COPD, a spirometry test, which measures how much air you can inhale and exhale and how quickly, is necessary. Tests results vary from mild to very severe depending upon the percentage of predicted FEV1 (the volume of air that can forcibly be blown out in one second, after full inspiration).

Blood tests are not necessary for diagnosis, but they help to understand the severity of the disease and its impacts on the body like insulin resistance, liver problems, anaemia etc. A radiographic scan will reveal lung hyperinflation, a flattened diaphragm, and increased diameter of the anterior-posterior.

Treatment Options for COPD and Sleep Apnea Overlap (COPD and Sleep Apnea)

Overlap syndrome, which involves having both COPD and OSA, leads to higher rates of illness and death than either condition individually. As such, it’s critical to manage both conditions concurrently to stabilize oxygen levels while sleeping, prevent repeated awakenings, and enhance life quality.

Lifestyle Changes and Exercise

• Organized exercise programs can improve AHI (an indicator of sleep apnea severity), daytime sleepiness, and sleep quality, especially in COPD patients. These exercises also help improve muscle wastage in these patients.
• Pulmonary rehabilitation, a program designed for lung disease patients, can reduce hospital visits, boost mood, reduce breathlessness, and enhance the quality of life.
• Weight loss immensely benefits OSA and obese patients. Contrarily, extreme weight loss or cachexia escalates the risk of death in advanced COPD patients. Advisedly, weight management should target enhancing health and not as a result of disease progression in severe COPD cases.

Healthcare professionals should also advise all patients to quit smoking, as this can significantly reduce the health risks associated with overlap syndrome.

Supplemental Oxygen

Additional oxygen is central to COPD management, as it improves daytime and night-time oxygen levels, decreasing the chance of death. Nevertheless, despite reducing oxygen slumps during sleep, its effectiveness in reducing obstructive events in OSA is not satisfactory. Supplements will be required when significant night-time oxygen slumps persist even after medication adjustments. These supplements do not seem to carry increased hypercapnia (build-up of CO2) risk.

Existing studies show increased heart irregularities due to oxygen supplementation in COPD patients prone to sleep apnea. Therefore, heart patients should be given oxygen cautiously. Also, oxygen therapy alone doesn’t adequately treat overlap syndrome. A recent trial revealed that night-time oxygen supplements neither reduced COPD patient deaths nor delayed long-term oxygen therapy progression. But, studies suggest that nasal high-flow air might be better than oxygen supplementation for night-time gas exchange. In a small study of 40 patients aged over 65, it was found that nasal high-flow oxygen therapy improved OSA severity, with almost half the patients having an AHI of fewer than five events per hour.

Drug Therapies

The drug regimen for COPD patients is defined by symptom severity and future exacerbation risk. Maintenance therapy mostly involves the use of inhaled bronchodilators, with the addition of inhaled steroids possible. All COPD patients should have a quick relief, or ‘rescue’, inhaler available. Moreover, receiving vaccinations for various respiratory ailments is vital to these patients.

Studies show barely any changes in sleep quality or oxygen saturation after treatment with inhaled long-acting beta-agonist and anticholinergic drugs. Theophylline reduces night-time low oxygen levels, benefiting OSA patients, but its side effects limit its use. The role of inhaled steroids is debatable, with one study showing improved AHI, night-time low oxygen, daytime PaCO2, and lung function by decreasing inflammation. Conversely, the use of inhaled steroids may lead to muscle weakening, worsening the collapsibility of the upper airway.

Respiratory stimulants also improve oxygenation but may not provide a noticeable clinical benefit, limiting their use.

Positive Airway Pressure and Noninvasive Ventilation

For patients with COPD-OSA overlap syndrome, PAP therapy is the go-to. PAP helps eliminate breathing events, restricts airflow, and counters snoring. Studies indicate an increased survival rate in OSA and COPD patients symptomatic for low oxygen when treated with PAP.

It’s essential to consider the root cause of a patient’s condition when choosing the type of PAP therapy in COPD cases. COPD patients with emphysema may experience more sleep-related breathing insufficiencies. These patients benefit from continuous positive airway pressure (CPAP) or similar techniques to support their breathing. CPAP has to be carefully adjusted so it does not overburden or under-support the lungs.

Although some recommend using bilevel positive airway pressure (BPAP) to aid in chronic bronchitis, its superiority over other forms of PAP therapy is not yet certain.

In recent times, the use of high-intensity non-invasive ventilation (NIV) has been reviewed, especially in COPD patients with chronic high respiratory failure conditions. This technique involves using high inspiratory positive airway pressure (IPAP) settings and a backup respiratory rate to normalize the level of CO2 in the bloodstream or achieve a 20% decrease in CO2 levels. If tuned correctly, this can potentially improve COPD patients’ survival chances.

The tuning of high-intensity NIV for patients with COPD-OSA and chronic high respiratory failure generally requires an IPAP of 15 to 20 cm H2O. The EPAP level is calculated based on either the pressure found during the sleep study or an estimate based on body weight.

What else can COPD and Sleep Apnea Overlap (COPD and Sleep Apnea) be?

If you’re experiencing the symptoms of a medical condition called COPD-OSA overlap syndrome, it might actually be another respiratory disease. One common confusion is with asthma and COPD happening together.

To correctly identify this overlap syndrome from others, doctors do a test called pulmonary function testing and look for symptoms that are specific to asthma. Plus, if you don’t show signs of obstructive sleep apnea (OSA), it could mean you don’t have COPD-OSA overlap syndrome.

Similar symptoms may come from many other conditions. For COPD, these include:

• Asthma that obstructs your airways but without any risk factors for COPD
• Blockage to your central airways
• Chronic bronchitis, but your spirometry (a test for lung function) is normal
• Bronchiectasis, which is a condition that enlarges your airways
• Heart failure
• Tuberculosis
• A condition causing narrowing of your bronchioles, called constrictive bronchiolitis
• A rare disease called diffuse panbronchiolitis
• Lymphangioleiomyomatosis, a rare disease that disrupts normal lung function

For obstructive sleep apnea alone, alternate conditions could be:

• Asthma that’s worse at night
• Excess fluid in the lungs, which is known as pulmonary edema
• A condition called idiopathic hypersomnia, which is excessive sleepiness with no apparent cause
• Not getting enough sleep over a long period
• Panic attacks that occur at night
• A lung condition called nonobstructive alveolar hypoventilation
• A syndrome related to obesity paired with hypoventilation or limited breathing, also known as Pickwickian syndrome
• A sleep disorder where you experience uncontrollable limb movements, known as periodic limb movement disorder
• Just simply snoring

What to expect with COPD and Sleep Apnea Overlap (COPD and Sleep Apnea)

Overlap syndrome, which is when a patient has both COPD and OSA, can be more dangerous compared to having just one of these conditions. It increases the chances of heart-related health issues, required hospital stays due to worsening COPD symptoms, and even death.

Treating OSA with a strategy called CPAP can significantly lower the risk of death and heart-related problems, no matter the patient’s age, gender, body weight, or if they have existing heart conditions. Other useful approaches include quitting smoking, long-term oxygen therapy, noninvasive ventilation, and medication. These are all crucial in reducing the health risks associated with COPD.

Possible Complications When Diagnosed with COPD and Sleep Apnea Overlap (COPD and Sleep Apnea)

According to the St. George’s Respiratory Questionnaire, people who suffer from overlap syndrome generally experience a poorer quality of life compared to those only dealing with COPD.

Overlap syndrome can lead to several complications:

• High blood pressure
• Coronary artery disease
• Heart attack
• Peripheral arterial disease
• Heart failure
• High cholesterol
• New-onset atrial fibrillation
• Pulmonary hypertension
• Worsening of COPD
• Bronchiectasis
• Car accidents
• Impaired executive function
• Increased medical costs

Improper treatment of overlap syndrome can result in reduced respiration, worsening lung function, and low therapy adherence, negatively affecting patient’s health. Research has shown that people with a type of lung disorder called emphysema are less likely to stick with CPAP therapy. This lack of treatment adherence can lead to worsening health outcomes. Moreover, bronchiectasis, which is associated with severe low nighttime oxygen levels and increased sleep time spent with SpO2 below 90%, is more common in individuals with overlap syndrome. This emphasizes the importance of the severity of diseases, especially COPD, in shaping the health outcomes of overlap syndrome.

Additional complications related to COPD include:

• Wasting and shrinking of skeletal muscles
• Anemia with normal red blood cell size and color
• Excessive red blood cell production
• Bone loss
• Depression and anxiety

Complications linked to Obstructive Sleep Apnea (OSA) are:

• Car accidents
• Stroke
• Insulin resistance
• Diabetes
• Fatty liver disease unrelated to alcohol
• Sexual dysfunction
• Potentially gout and venous thromboembolism

Preventing COPD and Sleep Apnea Overlap (COPD and Sleep Apnea)

Overlap syndrome refers to the simultaneous occurrence of two health conditions, chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA). COPD, a long-term lung disease, is primarily tied to smoking in rich countries and indoor air pollution in less affluent areas. Ranking as the third leading cause of death worldwide, people with COPD often suffer from breathlessness and continual coughing, usually with mucus.

OSA, on the other hand, is a sleep condition where a person’s airway becomes blocked or closes up, causing interruptions in breathing when sleeping. Despite these interruptions, people with OSA might not realize they’re happening. Instead, they might wake up choking or gasping for air, which their bed partners often notice along with loud snoring. Notable signs of OSA include restless sleep, morning headaches, a dry mouth or sore throat, waking up multiple times to urinate, waking up feeling tired or dull, and trouble thinking or remembering things. This disorder increases the person’s risk for insulin resistance, diabetes, heart disease, stroke, high blood pressure, heart attack, liver disease related to nonalcohol factors, and even death.

It can be hard to detect overlap syndrome because COPD and OSA share many symptoms. This syndrome significantly affects the patients’ quality of life and increases their risk for many health-related complications, like severe low oxygen levels during sleep, heart disease, worsening of COPD, irregular heart rhythms, and death. Therefore, healthcare professionals need to be very attentive in identifying this syndrome. Lung function tests are crucial for diagnosing COPD and a sleep study is needed to confirm OSA. These combined tests help doctors recognize and manage overlap syndrome more effectively.

It’s crucial to manage COPD and sleep apnea effectively to lessen risks related to heart disease and overall death rates. Addressing obesity, a key risk factor for OSA, requires targeted steps like structured weight loss plans. Possible treatments include pulmonary rehabilitation, therapy with positive airway pressure, stopping smoking, additional oxygen therapy, and medication. Besides, doctors put a high priority on giving recommended vaccinations to protect against lung illnesses, which pose an increased risk to people with COPD.