By Nikhil Ramburn and Sat Bir Singh Khalsa, Ph.D.
Chronic obstructive pulmonary disease (COPD) is an inflammatory lung disease characterized by obstruction of lung airflow. Emphysema and chronic bronchitis are the two most common conditions that contribute to COPD. COPD symptoms include difficulty breathing, cough, wheezing, and shortness of breath. Individuals suffering from COPD are at risk for more frequent respiratory infections, cardiovascular conditions, lung cancer, and pulmonary hypertension. An individual’s quality of life is likewise affected because of their inability to partake in daily activities due to difficulty breathing and this can lead to psychological distress and depression. A primary cause of COPD is long-term exposure to lung irritants that damage the lungs and the most common irritant is cigarette smoke. Other lifestyle risk factors include lack of physical activity, a shallow and rapid breathing pattern, and psychological stress. In fact, stress is a common cause of flare-ups in COPD patients since stress itself can cause shallowness of breath and faster breathing.
COPD is the third leading cause of death in the U.S. behind cancer and heart disease and more than 3 million Americans are diagnosed with the condition each year. Current estimates suggest that COPD costs the nation about $50 billion annually in direct and indirect healthcare expenditures. In addition to the large burden on the healthcare system, the economic costs of COPD are compounded by lost productivity to premature morbidity and mortality making this condition a major public health concern. Unfortunately, the conventional methods of treatments are only of limited efficacy for this condition since existing medications do not modify the long-term deterioration of lung function. The increasing prevalence of COPD requires that we develop effective behavioral interventions that go beyond symptomatic treatment and focus on rehabilitation. While aerobic exercise and strength training are moderately effective behavioral interventions, yoga and especially controlled yogic breathing (pranayama) have been shown to improve respiratory rate, oxygen levels in the blood, and overall quality of life in patients with COPD.
Several of the disease factors can be addressed by a therapeutic yoga intervention. Yoga may be a beneficial therapy for COPD because it involves physical activity along with breath regulation and has well documented stress-reduction benefits. Indeed, yoga training reduces respiratory rate and increases the strength of respiratory muscles. Slow, abdominal, yogic breathing is known to be more efficient in gas exchange of oxygen and carbon dioxide through deeper opening and expansion of the lungs. In addition, yoga decreases autonomic arousal and heart rate while reducing depression, anxiety, and panic attacks. Yoga also promotes healthy behavior habits, which can contribute to reducing lifestyle risk factors such as smoking. Finally, yoga may help COPD patients gain confidence that they can control their breathing, which along with the increase in physical performance could significantly improve their quality of life.
It is therefore not surprising that pranayama techniques have been shown to have therapeutic potential in treating COPD. In a case control study, conducted at a tertiary care institution in India, 50 individuals with moderate to severe COPD were divided into an intervention arm and control group. Half the individuals were trained in pranayama for 30 minutes twice a day while receiving their usual medication while the control group only received their usual medical treatment. Outcomes were assessed after 3 months and the intervention arm revealed significant improvement in the COPD assessment test and a 6-minute walk test, whereas the control group showed no such improvement. Researchers have suggested that pranayama results in various mechanisms of lung efficiency such as the rehabilitation of nonfunctional or closed airways. In addition, since pranayama promotes abdominal respiration it relieves the breathing diaphragm, improves oxygenation, and increases overall circulation. Pranayama also clears the airways and improves ciliary action, which helps to combat mucous secretions. Consequently, systemic inflammation is reduced and so are its manifestations. Therefore, more traditional yoga styles/practices that include pranayama as a key component are likely to be a better treatment strategy than the use of physical yoga exercises alone.
In the first meta-analysis and review of research on the efficacy of yoga for COPD, Liu et al. looked at five randomized controlled trials (RCTs) from 1978 to 2012 which encompassed 233 participants. The sample size per RCT ranged from 30 to 100 subjects per study and the duration of studies ranged from 12 weeks to 9 months. The reviewed trials all included pranayama alone or with yoga postures and the results reveal improvements in a variety of measures demonstrating improved lung capacity, ventilation and breath holding capacity after short-term yoga practice. In addition, studies suggested that yoga training may improve exercise capacity, prevent lung function decline, improve quality of life, and reduce dyspnea (a feeling of insufficient breathing or air hunger) in patients with COPD. However, these studies have a number of research design limitations including the small sample size of some studies. Despite these limitations, these preliminary results are encouraging and indicate that yoga training may be effective in improving lung function and functional exercise capacity in COPD patients compared with conventional therapy.
The first study to specifically measure the effects of yoga breathing on respiratory pattern and oxygen saturation in patients with COPD was published in 2009. This pilot study was conducted in Nepal by the team of Italian yoga researcher Luciano Bernardi and involved 11 patients, aged 59 to 80 years, with moderate to very severe COPD. Three of the patients were smokers, 2 nonsmokers, and 6 were former smokers. The patients practiced a complete, deep, slow yogic breathing pattern where they were asked to mobilize in sequence the diaphragm, lower chest, and then the upper chest during both inspiration and expiration. The main finding is that participants showed significant improvement in oxygen saturation (blood levels). To its credit, the yogic technique was not difficult to achieve and maintain, requiring at most 12 minutes to learn and patients reported feeling comfortable during the session. Despite the small sample size and lack of randomization, this pilot study provides encouraging preliminary evidence and encourages more extensive randomized trials to assess the long-term effects of yoga training for patients with COPD.
A more recent study evaluating yoga for COPD was a RCT involving 60 patients from the Guru Teg Bahadur Hospital in New Delhi, India. The 30 subjects from the experimental group practiced yoga for 2 months for 45 minutes in the morning and were monitored weekly for compliance at the cardiopulmonary laboratory. The transfer factor of the lung for carbon monoxide (TLCO), a measure of the ability of gas to transfer from the alveoli to the red blood cells, was recorded in both the control and experimental groups at baseline and after 2 months. This is significant because diffusion capacity is impaired in chronic lung disease and this was the first time that the effect of yogic exercises on lung transfer factor was evaluated. The results showed a statistically significant improvement after two months of yoga training whereas the control group which underwent conventional drug treatment had no change in TLCO.
In summary, studies to date have demonstrated the short-term efficacy of yoga to improve lung function and functional exercise capacity in patients with COPD compared with conventional therapy. This suggests that yoga could be a useful an adjunct pulmonary rehabilitation program for COPD patients. This is a cost-effective, easy to learn solution that addresses the underlying causes of COPD rather than just the symptoms. In addition, yoga provides the benefits of alleviating anxiety, improving quality of life and preventing deterioration of the lungs and musculature due to inactivity. Future research should ideally address the previous limitations of small sample sizes, lack of longer-term studies and inadequate data reporting and also provide information on the underlying mechanisms of yoga in COPD treatment. Innovative solutions such as Tele-Yoga interventions where classes are delivered via multipoint videoconferencing promise to make yoga therapy even more accessible and affordable to patients with COPD.