CE
Pharmacists: 1.00 contact hour (0.1 CEUs)
Released: January 29, 2024
Expiration: January 28, 2025
Some Things Haven’t Changed: COPD in the US
The annually updated GOLD report serves as go-to guidance for healthcare professionals (HCPs) around the world. The 2023 update included significant changes from 2022, and many of those changes were carried forward into the GOLD 2024 report. No matter the level of changes in the GOLD report and its subsequent recommendations for diagnosing COPD, how HCPs manage patients with COPD in the United States has remained unchanged for years.1
Approximately 16 million Americans have been diagnosed with COPD, and that number has increased annually. In addition, the CDC says that many more people have unrecognized COPD. These data make clear the need to improve the recognition and diagnosis of COPD.
Although COPD ranks sixth among the leading causes of mortality, the data were captured during the COVID-19 pandemic.2 Over the past decade, COPD has ranked as high as the third-leading cause of death.
If you look at disability-adjusted life-years, COPD—astoundingly—ranked second as a cause of disability in the United States in 2010, following ischemic heart disease. In 2016, it was third. A disability-adjusted life-year is the sum of years lost because of premature mortality or the years of life lived with disability adjusted for the severity of the disability. Therefore, it is clear that COPD is a debilitating disease with a high degree of mortality in the United States.3,4
Furthermore, COPD ranks 176th in terms of federal funding for research. Despite its high degree of disability and mortality, research funding is relatively low.5
When you think of patients with COPD, who is typically diagnosed? Traditionally, HCPs will say people who smoke. I will point out and reemphasize over the course of this module that COPD is no longer simply a disease of current or former smokers.
COPD: Prevalence and Burden
Looking at COPD prevalence and burden, what stands out to me here—outside of the estimated 3 million global deaths and it being somewhere between the second- and sixth-leading cause of death in the United States—is that there is a high prevalence of COPD in the Midwest and Southeastern states. Many of these states continue to have a high rate of smoking, as well as other environmental-related pollutions that may not have been previously considered as a contributor to COPD, whether people are diagnosed or not.1,6,7
GOLD Report Updates: Making Progress
The GOLD 2024 report continues to refine terminology and taxonomy related to COPD—specifically, etiologies of COPD. Furthermore, it includes more specific adjustments in defining pre-COPD vs COPD, discussions of treatment-related impact on mortality, and considerations regarding adherence. Finally, the role of CT imaging in diagnosing COPD is further explored.
Although some updates were added on the assessment and management of exacerbations, these are outside the scope of this module.1
GOLD: Redefining COPD
Perhaps one of the most significant changes carried forward in the GOLD 2024 report is the specific reference to the heterogeneity of the disease in defining COPD.1
It’s All Fun and Games Until It Overlaps
COPD formerly was defined as “patients with chronic bronchitis or emphysema.” These both fall under the same umbrella of diseases causing blockage in airflow and breathing issues as COPD.8 Within the past decade, asthma–COPD overlap syndrome (ACOS) was introduced as its own disease, which the GOLD report has since redefined; it no longer refers to ACOS as a disease, but rather the potential coexistence of asthma and COPD in patients.1
Previously, it was thought that uncontrolled asthma over the course of years may equate to COPD later in life, but as you can see from the Venn diagram (see slide), there is considerable overlap in the COPD etiology. A combination of factors, including environmental exposures or pollutions, cause airflow obstruction.9
Reframing COPD: Pathogenesis
The GOLD report outlines a mnemonic (see slide) that we should consider in all patients who present with shortness of breath or airway obstruction. Remember, COPD is no longer just a self-inflicted disease. HCPs should consider the dynamic interplay of genetics, environmental exposures, and the timing or prolonged nature of those exposures.1
Reframing COPD: Pathogenesis
The “G” in GETomics stands for genetics. The genetic heritability of COPD is moderate.10 When you look at genome-wide association studies, a few specific mutations have been identified, including α1-antitrypsin deficiencies and TERT polymorphisms. These are well established as contributors in COPD etiology.
In looking at the environment, of course, smoking is a well-established contributor to COPD. It is important to point out that this is not just a result of smoking cigarettes. It includes smoking cannabis, vaping, or using electronic cigarettes. Patients do not only have to be using combustible tobacco, nor must they be participating in other kinds of smoking. COPD could be a result of secondhand smoke or tertiary smoke exposure.1,11
Environmental exposures that are not related to smoking also can contribute to COPD development, including toxic biomass fuel pollutants. When I was in practice, I had several patients with COPD that was secondary to biomass fuel pollutant exposure. An example of this is the use of a woodburning stove to both heat the home and cook meals. This resulted in an exposure over 30-40 years, leading to an eventual COPD diagnosis.
Another example includes those who work in various factories. I had a patient who worked in an automobile factory for most of his life and was in a booth painting auto parts daily without proper airway protection. Fine particles from this environment would be inhaled without one’s knowledge. In the hair/cosmetic industry, constant exposure to different chemicals used to shape or style one’s hair can result in damage to the lungs. Furthermore, the news has reported on concerns regarding gas-burning ranges and their impact on our respiratory health.12 All kinds of environmental exposures are yet to be explored but may be causative in a patient’s eventual diagnosis of COPD.13
Then, air pollution is something we think about in countries that are less developed than the United States, but studies have found that many US public schools fall within 75-150 meters of busy roadways, offering long-term exposure to traffic pollution.14
Of course, you must then consider genetics and environmental exposures through the lens of time. Sometimes we do not develop our full lung function because of environmental exposures, chronic infections, or other factors that stunt pulmonary growth. Time is critical, considering that prolonged exposure to environmental pollutants or smoking can either stymie one’s pulmonary growth or hasten pulmonary decline.13,15,16
Reframing COPD: Level-Setting Terminology
As previously mentioned, the 2023 GOLD report provided terminology related to COPD that was expanded on in the 2024 report. There are several ways HCPs should look at COPD, and although defining COPD subtypes may not affect our clinical practice, it is important to be familiar with the different terminologies, especially as one reads the literature.
Early COPD, mild COPD, and young COPD are somewhat interchangeable in the literature. Per the GOLD report, early COPD is reserved for the experimental setting when discussing the “biological” first steps of the disease.
Then, mild COPD is sometimes equated to the pre-COPD and preserved ratio-impaired spirometry (PRISm) subtypes. Although COPD previously was considered to be a diagnosis of patients aged 40 years and older unless they had a known α1-antitrypsin deficiency, young COPD occurs in patients aged 20-50 years.
More applicable to HCPs clinically are the terminologies: pre-COPD and PRISm. Pre-COPD is characterized by presenting respiratory symptoms with or without detectable structural and/or functional abnormalities and without airflow obstruction on forced spirometry.
Those with PRISm have a forced expiratory volume (FEV1)/forced vital capacity (FVC) of 0.7 or greater, but their FEV1 percentage is predicted to be less than 80%. This would indicate the presence of airway obstruction without quite meeting the spirometry directed or requirements for diagnosing COPD.1
Proposed Taxonomy: Etiotypes for COPD
As we move forward in healthcare, there will be an increase in the literature on genetically determined COPD outside what is already known. We also will see a greater amount of literature attributing COPD to abnormal lung development, which primarily is related to a premature birth or low birth weight. In addition, maternal use of cigarettes or exposure to environmental pollutants may stymie a neonate’s pulmonary growth.
COPD related to infections is notated in the 2024 GOLD report, which references childhood infections and tuberculosis- or HIV-associated disease, which also can stunt pulmonary growth.
COPD-A includes childhood asthma that is inadequately treated, and then you have the COPD-U catchall, which is COPD of unknown cause.1
Proposed Taxonomy: Etiotypes for COPD
I now will focus this module on the management of environmental COPD, including COPD in those who do or have smoked (COPD-C) and those with COPD from other biomass and pollution exposure (COPD-P).1
COPD-P vs COPD-C
Some literature, including the GOLD report, compares COPD-C with COPD-P. COPD-P, or nonsmoking COPD, is more common in younger age groups and females, and it presents with milder respiratory symptoms and fewer exacerbations. There is a slower decline in respiratory function compared with patients who have COPD secondary to combustible tobacco exposure. Therefore, we suspect that there is a trend toward greater eosinophilic-driven inflammation.17
COPD, as a disease state, generally is characterized by neutrophilic inflammation, but a small percentage of patients (20%-40%) have eosinophilic inflammation. These patients may be the best candidates for adding an ICS to their treatment plan.1,18
A Move to Expand Diagnostic Criteria
There is a move to expand the diagnostic criteria for COPD. Prior to the 2023 GOLD report, the accepted diagnostic criteria did not fully capture the complexity or heterogeneity of the disease. Improvements still must be made in this regard, but at least the community currently is discussing some new criteria for diagnosing COPD.
According to the GOLD report, the diagnostic criterion for COPD is based solely on spirometry. It focuses on a single disease entity of COPD-C or COPD related to the use of combustible tobacco. This limited diagnostic criterion fails to identify COPD in its early stages, and that is the most significant drawback.
Moving forward, COPD should be considered in any patient with dyspnea, chronic cough, or excessive sputum production who has risk factors. Again, those risk factors have expanded quite a bit. COPD is no longer a disease of just smoking. Symptoms should be significant in nature, and HCPs should undergo active case finding instead of simply screening all patients. When a patient presents with signs and symptoms of COPD, we should ask questions related to their exposures and the timing of those exposures.
At present, forced spirometry remains a mandatory component for diagnosing COPD, but we are getting closer to a future where CT can expand our ability to detect COPD.1
Use of CT in Diagnosing COPD
Why use CT in diagnosing COPD? Well, CT is routinely available. Approximately 85 million CT scans are ordered annually in the United States for various reasons; low-dose CT scans are most commonly used for lung cancer screening in high-risk patients who could have COPD, per recommendations.19,20
Spirometry is known to have an insensitivity to early disease and often is interpreted incorrectly if not performed by a pulmonologist or someone who is well trained in this specialty. HCPs could evaluate CTs for emphysema, air trapping, or airway remodeling, which could lead to accurately diagnosing COPD.21-24
Advancements in CT have enhanced understanding of the disease and its phenotypes. Therefore, CT scans also could provide information related to COPD comorbidities, in particular, coronary artery calcium, pulmonary artery enlargement, bone mineral density, and muscle mass.1,25
The Future of COPD Diagnosis?
Lowe and colleagues26 and Thomashow and colleagues27 have published schematic considerations that may be the key to improving diagnoses of COPD in the next 3 years; in these, CT scans, spirometry, presenting symptoms, and related exposures all can factor into the likelihood of COPD.
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