COPD cases in women are projected to increase at a rate five times higher than in men through 2050, while reproductive factors emerge as potential risk markers. 

By Alyx Arnett


Once thought of as “a man’s disease,” chronic obstructive pulmonary disease (COPD) is now more common in women, with mortality rates surpassing those in men.1

The American Lung Association recognized this tipping point in 2018, indicating that women accounted for 58% of people living with COPD in the United States and 53% of deaths.2 The trend has continued in recent years, with women making up a growing number of hospitalizations. A recent study found that COPD hospitalizations have risen sharply for older women while hospitalizations for older men have declined.3 

New projections suggest this disparity could widen further. By 2050, the number of women with COPD globally is expected to increase by 47%, compared to 9% in men.4 

“The faces of COPD have changed over the last couple of decades,” said Albert Rizzo, MD, FACP, chief medical officer for the American Lung Association. “Although both men and women continue to have COPD, it’s gradually rising and maybe in women a little bit more.” 

Amid this upward trajectory of COPD in women, researchers have been delving deeper into the factors fueling this growth. New research has revealed that several female reproductive factors, including the age of first menstruation and early menopause, are linked to a heightened risk of COPD,5 while factors like indoor air pollution from cooking and increased smoking among women continue to be implicated.4 

COPD’s Hold on Women Expected to Continue

A recent study projected the burden of COPD out to 2050, looking, in part, at trends based on sex.4 While researchers expect the global prevalence to remain somewhat higher in males than females (10.6% versus 8.3%, respectively), a concerning finding, according to study co-author Meredith Barrett, PhD, vice president of population health research at ResMed, was the significant increase in case counts expected for women. 

“We’re actually starting to anticipate that we’ll begin to see female prevalence approaching that of males by 2050,” said Barrett. 

Researchers predict a 47.1% increase in the number of COPD cases for women by 2050, over five times higher than the 9.4% increase predicted for men. The growth is projected to be the highest among women in low- and middle-income regions. 

One factor likely influencing this growth is household air pollution due to biomass fuels from cooking and heating, according to the researchers. Barrett said it continues to be one of the largest exposures for women, especially in low- to middle-income countries. “We anticipate that to improve over time, but it’s certainly going to continue to be the primary way of cooking and heating for quite a while,” said Barrett. 

The increase in tobacco use among women—peaking at 33% in 1965 after being at 6% in 1924—is another contributing factor, along with a demographic shift toward an aging population, Barrett said.6 Additionally, she pointed out that restricted access to healthcare in low- to middle-income areas is likely to influence this trend as well.

Reproductive Factors Linked to COPD Risk

Previous research has suggested that female sex hormones play a role in women’s susceptibility to COPD.7 

A 2019 study explored this further, becoming the first to assess COPD risk based on several reproductive health indicators.8 Researchers determined that several indicators—including late age of first menstruation and early menopause—were associated with COPD-related hospitalization or death, as well as diminished lung function. 

Subsequent research further illuminated the link between reproductive health and COPD risk, also linking several reproductive factors to increased COPD risk, including age of first menstruation; number of children; a history of infertility, miscarriage, or stillbirth, especially multiple miscarriages or stillbirths; and age at menopause.5

A surprising finding of this latest research, according to study co-author Gita Mishra, PhD, FAHMS, CStat, of the School of Public Health and Faculty of Medicine at The University of Queensland, was that a U-shaped pattern emerged for the age at which menstruation first started. Those who began menstruating before or at the age of 11 were 17% more likely to develop COPD than those who did so at the age of 13. After the age of 16, the risk was 24% higher.

Moreover, the study revealed that women with children faced a greater COPD risk than those without. Specifically, having more than three children was associated with a 34% increased risk compared to having two, and women with one child faced an 18% greater risk. 

Additionally, women who experienced infertility were at a 13% higher risk compared to those who did not. For those who had been pregnant, experiencing miscarriages was linked to a 15% increased COPD risk, escalating with additional miscarriages: a 28% increase for two and 36% for three or more. Likewise, stillbirths correlated with a 42% heightened risk, which also intensified with the number of stillbirths.

Early menopause, occurring before the age of 40, was linked to a 69% increased risk of COPD, compared to those experiencing it naturally around ages 50-51. Conversely, the risk dropped by 21% for individuals who entered menopause at the age of 54 or later.

“These findings highlight that female reproductive histories could be used as markers of their future lung health,” said Mishra. “These findings can assist clinicians in identifying women at higher risk of COPD, implementing timely prevention strategies, and potentially reducing the disease burden in later life.”

Mishra said future studies are needed to understand the underlying mechanisms linking female reproductive histories and COPD, including whether estrogen may be protective later in life. 

Declining COPD Mortality Among Women

While COPD cases have been climbing in women, new research indicates a more positive trend: The death rate may be declining. 

According to the American Lung Association’s recently released COPD Trends Brief, the COPD death rate among women has decreased by 15% since 2017 after remaining relatively flat for close to 20 years.9 Rizzo attributed this decline to improved disease awareness, earlier diagnosis, and more effective treatment strategies. 

However, he said gender disparities in diagnosis and treatment still exist, noting that research indicates that men may be put on medications sooner—and on more medications—than women. “But I think we’re catching up. The fact that women are being diagnosed allows them to be put on the right medication sooner,” Rizzo said. 

He said continued awareness among physicians that COPD can present in both men and women will support further progress in diagnosis and treatment. “Maybe their radar should be up a little bit more with regard to seeing women who may have symptoms related to shortness of breath, cough, sputum, and have a little more awareness that this may be COPD,” Rizzo said. 

Atul Malhotra, MD, research chief of pulmonary, critical care, and sleep medicine at the University of California, San Diego, said COPD can no longer be stereotyped as a disease that affects older men who smoke. “There are plenty of women and other people who don’t meet the stereotypes who have COPD,” he said. “There are lots of patients at risk of this condition that don’t get diagnosed or get misdiagnosed with asthma or some other condition or told they’re out of shape or this kind of thing. Many have a treatable condition that gets ignored.”

Malhotra emphasized that besides moving beyond its traditional label as a “man’s disease,” it’s also critical to recognize that COPD isn’t solely a smoker’s disease. The 2024 Global Initiative for Chronic Obstructive Lung Disease (GOLD) guide dropped smoking as a part of the definition in recognition of air pollution and other contributing factors.10 “The problem of COPD in nonsmokers is something that should also be emphasized,” Malhotra said. 

Oxygen Therapy and Noninvasive Ventilation

Outside of pharmacotherapy for COPD, oxygen therapy and noninvasive ventilation are used for disease management. Long-term oxygen therapy (over 15 hours a day) has been shown to increase survival in COPD patients with severe resting hypoxemia,10 and the American Thoracic Society (ATS) strongly recommends its use in these patients.11 

To improve mobility outside the home for patients on long-term oxygen, three types of portable oxygen delivery systems are available: metal oxygen cylinders, portable oxygen concentrators (POCs), and liquid oxygen canisters.11 The devices differ in size, weight, levels of pulse- or continuous-flow settings, capacity, and supply duration, according to the ATS. 

For patients who require high-flow rates and need to be outside the home for extended periods, the ATS suggests liquid oxygen canisters due to their higher capacity compared to POCs and metal cylinders. Many durable medical equipment companies in the United States offer POCs as a portable option with a stationary concentrator.11

Noninvasive ventilation is sometimes used in patients with stable, very severe COPD.10 Noninvasive positive pressure ventilation (NPPV) is the standard of care for COPD patients hospitalized with an exacerbation and acute respiratory failure.10 Nasal prongs and Venturi masks are commonly used to deliver oxygen to these patients, though research indicates Venturi masks may be superior in maintaining adequate levels of arterial oxygenation.12 NPPV can also be used to treat patients at home following hospitalization. 

A study of COPD patients with persistent hypercapnia after hospital discharge due to an exacerbation compared the effects of home noninvasive ventilation plus oxygen to oxygen alone on time to readmission or death.13 Results showed that adding noninvasive ventilation to oxygen therapy prolonged the time to readmission or death within a year. 

Researchers said the findings support screening patients with COPD after acute noninvasive ventilation to identify persistent hypercapnia and initiate home noninvasive ventilation. The ATS recommends14 nocturnal noninvasive ventilation, in addition to usual care, in patients with chronic stable hypercapnic COPD.

RT 

Alyx Arnett, is associate editor of RT. For more information, contact [email protected].

References

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