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Researchers say women tend to have smaller lung airways than men. Joos Mind/Getty Images
  • Almost 16 million people in the United States have been diagnosed with chronic obstructive pulmonary disease (COPD).
  • More women are now living with COPD than men in the United States and more women die from the disease than men.
  • Researchers say women tend to have small lung airways and that increases the risk of developing COPD as well as the risk of more serious disease.

Women may have a higher risk of chronic obstructive pulmonary disease (COPD) due to small airways in the lungs.

Research published today in the journal Radiology reports that structural differences between the sexes may explain the difference in prevalence and outcomes of COPD between men and women.

“The differences in airway dimensions even after adjusting for height and lung size, and the greater impact of changes in airway size on clinical outcomes in women, was remarkable in that women appear to have a lower reserve against developing airway disease and COPD,” Dr. Surya P. Bhatt, the lead author of the study and an associate professor of medicine in the Division of Pulmonary, Allergy and Critical Care Medicine at the University of Alabama at Birmingham said in a press release.

The researchers found that even among those who never smoked or had smoked less than 100 cigarettes over their lifetime, the lung airways in women were still smaller than in men.

They examined data from nearly 10,000 people. Some were never smokers, some were current smokers, and some were former smokers.

Among the 420 people who had never smoked, the researchers found that men had thicker walls to their airways than women. The dimensions of the airways were also smaller in women than in men.

In the 9,363 former or current smokers in the study, men again had thicker airway walls and women had narrower airways than men.

The researchers stated these differences resulted in higher levels of shortness of breath, lower lung function, poorer respiratory quality of life, and worse survival outcomes in women than men.

Dr. Jimmy Johannes, a pulmonologist and critical care medicine specialist at MemorialCare Long Beach Medical Center in California, says the study helps to explain some of the disparity between the sexes when it comes to lung disease.

“The logical potential difference here is that the larger your lung, the more lung disease you can tolerate before you might develop symptoms or other complications related to those lung diseases,” he told Healthline.

COPD is a name for a group of diseases that cause breathing difficulties and blockages to the airways.

Almost 16 million people in the United States have been diagnosed with COPD, but it’s likely millions more are living with COPD without a diagnosis.

In the past, COPD had typically been viewed as a man’s disease. However, since 2000 more women have died from COPD than men in the United States. More women live with COPD than men and while the death rate for COPD among men has dropped in the United States, the death rate hasn’t dropped for women.

Experts say smoking likely plays a role.

“It seems like women don’t need to smoke as much to develop the same amounts of disease as men. So, their dosing requirements to developing disease seem to be lower than men,” Johannes said.

The Centers for Disease Control and Prevention (CDC) notes that in the United States women who smoke develop COPD younger than men who smoke even if they smoke less than men.

Dr. Rajkumar Dasgupta, a pulmonologist with Keck Medicine of USC, says estrogen is a factor in this disparity.

“When we talk about estrogen, it really changes the metabolism of some of the chemicals of cigarettes. It really makes our airways more susceptible to damage. Also, estrogen up-regulates some genes which control mucus secretion and people with COPD have a lot of mucus production,” he told Healthline.

Data from the CDC shows that in 2018 chronic lower respiratory disease (mostly COPD) was the fourth leading cause of death among women in the United States.

Women tend to be diagnosed with COPD later than men when the disease is more advanced. Treatment in the advanced stages of the disease is less effective, and women and men respond differently to treatments.

COPD can cause both emphysema and chronic bronchitis.

These can appear as a variety of symptoms including shortness of breath, difficulties taking a deep breath, frequent wheezing or coughing, and an excessive amount of mucus, phlegm, or sputum production.

“It’s incredibly debilitating, the quality of life is actually potentially worse than stage four lung cancer patients, Dr. Brooks Kuhn, a pulmonologist at the University of California Davis, told Healthline. “Unfortunately, [people with COPD] don’t get a break from it. They are always out of breath, are always uncomfortable because of that. As you can expect, the rates of depression and anxiety are three to five times more common in the COPD population,”

“It’s incredibly difficult. A patient can’t get out, they can’t interact with their family, they can’t go out and do the things that refresh them and make them human beings,” he added.

Experts say the study is a step in the right direction of developing new therapies for COPD that consider the differences in the lungs between the sexes. However, it may take a long time to develop such therapies.

“The sad reality is we just don’t have good enough tools right now to really, really move the needle as much as we need to to help these patients and their suffering,” Kuhn said.