COPD: Respiratory Health Inequalities

Chronic obstructive pulmonary disorder (COPD) is a respiratory condition that causes respiratory airways to be partially blocked, negatively impacting a person’s ability to breathe. COPD can be associated with obstructions that affect the bronchi or the alveoli. Hence, COPD can also be referred to as bronchitis and emphysema. COPD is a condition that often co-occurs with other morbidities and shares symptoms with other respiratory maladies, such as asthma. However, the global burden of COPD is disquieting; it is currently the third most common cause of mortalities and is projected to lead to more than 5.4 million deaths each year by 2060. Although COPD is primarily linked to the regular inhalation of tobacco smoke, and therefore often has a stigma attached to it as it can be perceived as a self-inflicted disease, a range of other factors have been connected to its pathogenesis (Agusti et al., 2023).

A trend recently observed is that COPD is more prevalent among people of lower socioeconomic status (SES) (Pleasants et al., 2016). According to the World Health Organisation (WHO), 40% of cases can be attributed to smoking in low-income countries. Hence, a majority of COPD afflictions result from other determinants that are often not addressed in intervention plans (World Health Organization [WHO], 2023).

Therefore, this article aims to educate about the deleterious impacts that COPD can have on a person’s life by outlining the pathophysiology and symptoms of the disease while also mentioning the potential causes. It will then focus on the challenges that impede the quality of diagnosis and treatment of COPD, especially in low-income countries. Finally, recommendations will be given on what actions should be taken to tackle these issues.

Figure 1: An summary of the symptoms and causes of COPD (Patel, n.d.).

Pathophysiology

COPD is an inflammatory disease. The common pathogenesis pathway involves inhaled particles acting as triggers for the local immune response in the respiratory system. A range of external signals can cause immune cells to mount an inflammatory response, ranging from pathogens to chemicals. The first responders of the immune system are cells of the innate immune system, such as macrophages and neutrophils. The activation of these cells drives a cascade of events, like the secretion of chemical messengers and the switching on of certain factors, leading to inflammation. Inflammation is a natural response to infection or exposure to foreign substances and is conventionally a useful mechanism; it fends off the invading particles and clears them out of the body. However, inflammation can become chronic if the exposure to the trigger is continual (Hikichi et al., 2019).

Over time, the hyperactivated state of the immune system can initiate irreversible structural changes in parts of the respiratory system. Some of the most common alterations include the destruction of the elastic walls of the alveoli (site of gas exchange in the lungs) and the accumulation of mucous, secreted by goblet cells, in the airways. Consequently, obstructions in the respiratory system develop (Rodrigues et al., 2021). COPD can persist asymptomatically while this manifests and only becomes obvious when the structural changes are severe. Emphysema, bronchitis, and the enlargement of lung tissue, due to the inability to exhale air out of them, can all be present when a patient is affected by COPD (Devine, 2008). Exacerbations of the disease can be seen whenever the respiratory system reencounters the trigger (Agarwal et al., 2023).

Figure 2: Comparison between healthy lung and lung with COPD (Supnik, 2019).

Symptoms of COPD and their Impact on Daily Life

People living with COPD can experience heterogeneous respiratory symptoms. Symptoms can vary as the disease progresses but also because of changes in environmental conditions and time of day. The key signs that may suggest that you have COPD include dyspnoea (shortness of breath), a regular cough, and a hyperproduction of sputum. These symptoms are directly associated with the pathological changes that occur in the lungs and the airways (NHS, 2018). Yet, these localised symptoms can then lead to the deterioration of a person’s overall health. COPD patients report that their symptoms are most burdensome in the mornings as they hamper their ability to go about their morning routine.

Additionally, individuals who have trouble breathing tend to abstain from physical exercise which, in the long term, weakens their muscles and worsens their prognosis. Furthermore, as breathing is a vital function, COPD symptoms can lead to mental distress and trouble sleeping (Miravitlles & Ribera, 2017). A study that collated patients’ opinions on how living with COPD affected them throughout the day showed that those who experienced one or more respiratory symptom was more likely to be affected by depression and anxiety than someone who was asymptomatic (Miravitlles et al., 2014). Overall, difficulty breathing and other symptoms that COPD patients present with can greatly reduce a person’s quality of life.

Causes of COPD

Smoking

Exposure to cigarette smoke has been held responsible for a large percentage of COPD cases. Inhalation of cigarette smoke exposes the respiratory system to a variety of toxic substances, such as tobacco, tar, and oxidants (Laniado-Laborín, 2009). Smoking is directly linked to the development of COPD, with recent studies portraying that even secondary exposure to cigarette smoke can be relevant in predisposing someone to the condition. Cigarette smoke induces inflammation and is a significant driver of lung cell death, mucous production, and alveolar disruption. Presently, smoking cigarettes is considered to be the most prominent risk factor for developing COPD (Song et al., 2021).

Figure 3: Smoking cessation (Armand, 2016).

Environmental Factors

Planetary health refers to the interdependency of the well-being of the planet (the environment) and the health of the people that occupy it. It is undeniable that human actions are leading to the degradation of the Earth, with climate change, global warming, and air pollution being poignant issues. It is now being acknowledged that human health is also being negatively impacted by these changes (Iyer et al., 2021). Air pollution specifically has been a point of focus when exploring the alternative causes of COPD. In a large analysis study performed on 452,762 participants from the UK, the researchers concluded that people who lived in areas where air pollution with nitrogen species and particle matter was prevalent were more likely to develop COPD than those who lived in regions with cleaner air (Wang et al., 2022).

Furthermore, an important factor that came to the attention of researchers is the effect of biomass fuel emissions. COPD mortality is heavily concentrated in low-income countries, where the use of biomass fuels is common. Therefore, researchers wanted to identify if there is a relationship between the use of biomass fuels and COPD morbidity in low-income countries. It is now approximated that 41% of the global population relies on biomass fuels (organic products such as food waste and wood) for energy. When these products are burned, mostly on an open fire, pollutants are released into the surrounding air. These energy sources are usually utilised in homes and therefore, lead to household air pollution. Results from analysis studies suggest that high household air pollution from biomass fuels can drastically increase a person’s chances of acquiring COPD (COPD being almost three times more likely in those who employ biomass fuels in their daily chores than those who do not) (Torres-Duque et al., 2021). Furthermore, predictions for the future suggest that the effects of COPD on a person’s quality of life will continue to worsen as soaring global temperatures and increases in humidity will cause more severe exacerbations of COPD (Tran et al., 2023). Consequently, environmental factors as potential causes of COPD should not be ignored and should be explored further to mitigate the impact they have on human health.

Figure 4: Woman using biomass fuels for cooking (Vohra, 2022).

Occupational Exposures

Reactants that can cause an inflammatory response in the respiratory system, leading to the development of COPD, are also present in fumes and dust. Occupational exposure to irritants, in coal miners, construction workers, and factory workers, has become an important risk factor for COPD. It is suspected that individuals with a low SES are more likely to have an occupation that leaves them unprotected from chemicals and fumes compared to those with a higher SES. As a result, occupational exposure as a cause of COPD can be a major factor that increases the burden of the disease in low-income countries (Pleasants et al., 2016). However, it is rarely a point of attention in medical policies and treatments of COPD, potentially due to the lack of awareness. It is difficult to address occupational exposures as these cases can be crudely underdiagnosed. This can occur due to a person’s lack of knowledge that their job poses a risk to their health. The treatment of these patients also proves difficult as they may be unwilling to give up their jobs, as this may be their only source of income, or may have no access to protective gear (Murgia & Gambelunghe, 2022). Therefore, more research is needed to determine what groups are most at risk of occupational exposure and strategies need to be implemented to make work environments safer, especially in low-income countries.

Challenges of Diagnosing and Managing COPD

Conventionally, COPD is diagnosed based on a patient’s symptoms and by performing a spirometry test. Spirometry can be used to determine the volume of air that a person can forcedly exhale (Forced expiratory volume). Presently, spirometry is considered the gold-standard test when diagnosing COPD and is relatively easy to implement in screening (Vogelmeier et al., 2020). Despite this, studies continue to display the underutilisation of spirometry, the limited availability of screenings and the absence of training in medical professionals. A COPD intervention in Quebec highlighted the lack of screening services and the lack of professional knowledge as key problems that limit the effective diagnosis of COPD. In addition to this, due to a lack of awareness about COPD in the public, patients tend to understate the severity of their symptoms, leading doctors to incorrectly grade the stage of COPD (Vachon et al., 2022). A literature review of the availability of spirometry tests in Africa portrayed that access to the required equipment, training and specialists is very poor. These issues are commonalities that are observed in most low-income and middle-income countries (Masekela et al., 2018). When drafting health policies and interventions, priority needs to be given to these regions, where the burden of COPD is higher (Meghji et al., 2021). Steps need to be taken to improve the provision of training and education in vulnerable countries, the distribution of spirometry equipment and the awareness of the population about the symptoms of COPD.

Figure 5: Spirometry test (Cleveland Clinic, 2022).

Treating COPD encompasses the management of symptoms and the prevention of disease progression. Although medication is commonly prescribed to relieve symptoms, upstream interventions are needed to target the causes of the disease (NHS, 2019). As exposure to cigarette smoke is the main contributor to COPD pathogenesis, smoking cessation is an intervention often being implemented. Strategies to quit smoking that are recommended include nicotine alternatives, therapy, and the use of chewing gum. Although cessation programs are well-established tools, the propensity to smoke cigarettes remains higher in low SES groups than in higher SES groups. Furthermore, cessation programs lose their efficacy when delivered to people of lower SES, with people being less likely to complete the program and higher rates of reverting to the habit being seen. This suggests that cessation programs need to be flexible and require adjustment for the appropriate audience if they currently fail to be effective in vulnerable groups. For example, a study conducted in the Netherlands hypothesised that a rolling group intervention (which had no set start or end date) would be more appealing to individuals from low SES groups (Landais et al., 2021).

Yet, as aforementioned, smoking is not the only factor that leads to the development of COPD. Environmental factors, such as household air pollution and exposure to toxic fumes, can also induce an inflammatory response in the airways. Pulmonary rehabilitation is a management strategy that is often offered to people living with COPD (NHS, 2019). It is a multifaceted intervention; sessions typically include physical training as well as education about the disease, symptoms, and positive lifestyle changes.

Figure 6: Pulmonary rehabilitation infographic (Chartered Society of Physiotherapy, 2019).

Despite being prominent risk factors, especially in low-income countries, discussions about the environmental triggers of COPD are usually omitted from the educational sessions. Researchers Souto-Miranda and colleagues trialled a pulmonary rehabilitation intervention that had a dedicated session on indoor and outdoor air pollution. All participants had been diagnosed with COPD and were aware of the effects of pollution on their condition. However, the educational session proved useful in helping individuals work around environmental triggers instead of completely avoiding them, which is what the participants believed to be the only way of tackling the issue before the session. Similar educational sessions must be delivered to patients living in low-income countries who are more prone to using biomass fuels daily (Souto-Miranda et al., 2020). Additionally, work providers should minimise the health hazards that their workers are exposed to by using cost-effective interventions. This is especially important for people from low SES groups as they are at the highest risk of occupational exposure to dust, pollution, and fumes.

Conclusion

Chronic obstructive pulmonary disease (COPD) is a condition with a high global burden. It has a complex pathogenesis that involves inflammation in regions of the respiratory symptoms. People living with COPD experience debilitating symptoms, including dyspnoea, a constant cough and sputum production. There is a disparity in the populations that are affected by COPD, with people from low-income countries and those from groups of lower socioeconomic status suffering the highest morbidity and mortality rates. This outcome can be attributed to health inequalities caused by upstream factors. To improve the situation, efforts should be made to educate vulnerable groups about the existence of COPD, provide adequate equipment and training to improve diagnosis, and modify management strategies to make them accessible and useful for marginalised populations.

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