• Posted May 9, 2025

Smoking Doesn't Explain Increased COPD Risk For Women

Smoking can't explain why women are more at risk for COPD, a new study says.

Women are about 50% more likely than men to develop COPD even though they are less likely to smoke, researchers reported May 8 in the journal BMJ Open Respiratory Research.

Smoking tobacco is the main cause of COPD, the umbrella term for chronic breathing problems like emphysema and bronchitis, researchers say.

But the COPD rate is higher among women than men, even though women don’t smoke as much as men, results show.

The results refute the notion that women are more vulnerable to tobacco smoke than men, which had previously been floated to explain why more women suffer COPD, researchers said.

“The higher risk of COPD in women was not explained by higher susceptibility to cigarette smoke as measured by either smoking status or pack-year exposure,” wrote a team led by Dr. Alexander Steinberg, an assistant professor of clinical practice at the University of Washington in Seattle.

“In fact, women had a nearly identical increase in risk of COPD for every 10 pack-years of cigarette use when compared with men,” researchers wrote. Pack-years measure how much a person has smoked by multiplying the packs smoked per day by the number of years a person has smoked.

“This then begs the important question of what is driving high rates of COPD among women,” researchers added.

For the study, they analyzed responses from more than 12,600 women and nearly 10,400 men 40 and older who participated in the National Health Interview Survey, an annual poll conducted by the U.S. Centers for Disease Control and Prevention to track American health.

Women were less likely to be current or former smokers than men, and those who did smoke tended to burn through fewer cigarettes per day than men, researchers found.

Women also were more likely to have smoked for fewer years, and less likely to have started smoking younger than 15.

Nevertheless, just under 8% of women suffered from COPD compared to about 6.5% for men, results showed.

Women with COPD were more likely to have never smoked cigarettes than men with the condition, nearly 27% compared with just over 14%, researchers found.

They also were less likely to use other tobacco products except for e-cigarettes, nearly 27% compared with 20%, the study says.

Overall, women had a 47% higher risk of being diagnosed with COPD than men, after accounting for other risk factors, researchers concluded.

This gender difference persisted regardless of smoking history. Women who never smoked were 62% more likely to be diagnosed with COPD than men, and those who had ever smoked were 43% more likely, results show.

Several theories might explain why women are more at risk for COPD even though they don’t smoke as much as men, researchers said.

“Studies have suggested that increased inhalation exposure from traditionally female-predominated occupations, home heating and cooking, aerosolized hair and beauty products and household cleaning products may contribute to higher rates of COPD in women,” researchers wrote.

Women also tend to have smaller airways than men, which might make them more susceptible to breathing problems, researchers noted.

“Our research raises uncertainty about the common assumption that increased vulnerability to cigarette smoke is driving the gender divide in COPD,” researchers concluded.

More information

Cleveland Clinic has more about COPD.

SOURCES: BMJ Open Respiratory Research, May 8, 2025; BMJ, news release, May 8, 2025