Men, women with asthma experience differences in control, lung function, exacerbations

Key takeaways:

• Women had higher Global Initiative for Asthma treatment steps.
• Asthma Control Questionnaire scores included 0.83 for women and 0.66 for men.
• 60.5% of men and 44.4% of women had persistent airflow limitations.

WASHINGTON — Women with asthma had worse disease control and higher risks for exacerbations compared with men, according to data presented at the American Thoracic Society International Conference.

But while women also have more small airways dysfunction, persistent airflow limitations are more prevalent among male patients, Susan Muiser, MD, department of pulmonology, University Medical Center Groningen, and colleagues wrote.

“It is already known that there is a sex disparity in asthma and that this sex disparity is multifactorial. However, a lot is still unknown,” Muiser told Healio.

Previous studies about sex differences in patients with asthma, Muiser said, lacked extensive clinical characterization or information about differences across all asthma severities. Also, she continued, they often did not account for the presence and extent of small airways dysfunction (SAD).

“With the ATLANTIS study, we have an opportunity to gain more knowledge about these topics,” Muiser said.

The observational cohort ATLANTIS study followed 773 adults (58% women) aged 18 to 65 years with mild, moderate or severe asthma from nine countries for a year.

“In the ATLANTIS study, we show that female patients have more SAD as reflected by worse impulse oscillometry (IOS) results,” Muiser said.

At baseline, the women had more severe asthma than the men based on which Global Initiative for Asthma (GINA) treatment step they were on (P = .042). Asthma Control Questionnaire scores included 0.83 for the women and 0.66 for the men (P < .001).

Impulse resistance at 5 Hz minus 20 Hz (R5-R20) totals included 0.06 kPa/L/second for women and 0.04 kPa/L/second for men (P = .002), and areas under the curve included 0.41 Hz*kPa/L/second for women and 0.23 Hz*kPa/L/second for men (P < .001), indicating that women experienced more SAD, Muiser said.

However, the men were diagnosed with asthma at a median age of 22 years whereas the women were diagnosed at a median age of 26.04 years (P = .028), and persistent airflow limitations were more frequent among men (n = 193; 60.5%) than women (n = 196; 44.3%; P < .001).

Along with higher blood eosinophil and monocyte levels, the researchers called female sex an independent predictor of increased risk for exacerbations.

ATLANTIS is the first study with such a large sample size to show significant differences between men and women with asthma in all IOS results, suggesting greater resistance in the central and peripheral airways of women with asthma, Muiser said.

But proper reference values are currently lacking, she continued, so clinicians should account for sex when determining reference values for IOS results.

“The results of this study reaffirm that, in adulthood, female asthma patients experience more symptoms, a finding that is sensible in a cohort of female patients with more exacerbations, airway hyperresponsiveness and SAD,” Muiser said.

Yet the men in the cohort had more severe airflow obstruction and greater prevalence of persistent airflow limitation (126 vs. 122; P < .001).

“This highlights the fact that the interplay between objective parameters of asthma, subjective experience of symptoms, and clinical outcomes is highly complex,” Muiser said.

As a result, Muiser said, personalized treatment that accounts for sex for patients with asthma is important.

“We think our findings highlight that a different approach to treatment of female asthma patients might be warranted to achieve symptom control,” she said.

“Further research is necessary to unravel the differences between male and female asthma patients, ideally leading to evidence-based personalized treatment of asthma patients that takes sex into account,” she concluded.

For more information:

Susan Muiser, MD, can be reached at s.muiser@umcg.nl.