Women Smoked Less Than Men but Were More Severely Affected by COPD

Women with chronic obstructive pulmonary disease (COPD) reported smoking fewer cigarettes than men but experienced worse symptoms, reported lower quality of life, and suffered more frequent and severe acute exacerbations due to the progressive lung disorder, according to an abstract presented at the 2019 American Thoracic Society (ATS) International Conference, held May 17-22 in Dallas, Texas.

“Women comprise 50% of the US COPD population and represent a growing proportion of incident cases,” researchers said. “Risk factors for incident COPD, clinical phenotype and prognosis differ by sex.”

Researchers analyzed data from the Subpopulations and Intermediate Outcome Measures in COPD study (SPIROMICS) to examine how COPD outcomes differed by gender. SPIROMICS was a prospective cohort study designed to identify novel COPD subgroups and intermediate markers of disease progression. Considering nearly half of its participants were women and it had collected data on COPD morbidity measures and hormonal exposure history, researchers determined it was distinctively poised for their analysis.

Study investigators examined baseline data from 1832 SPIROMICS participants with more than 20 pack years of smoking history and COPD. Markers of COPD morbidity included respiratory-specific quality of life measures (QoL) from scores from the Saint George’s Respiratory Questionnaire (SGRQ), general QoL measures from scores from the 36-Item Short Form Health Survey version 2 (SF-36), recorded distance on a 6-minute walk test (6MWT), symptom scores from the modified Medical Research Council questionnaire (mMRC) and COPD Assessment Test (CAT), and both the frequency and severity of acute exacerbations. Frequent acute exacerbations were defined as 2 or more suffered per year. Researchers considered an exacerbation to be severe if it resulted in hospitalization or an emergency room visit.

A total of 781, or 42%, of participants included in the analysis were women. Among women, age, race, smoking status, and predicted forced expiratory volume in 1 second (FEV₁) percentages were similar to men. The mean number of reported smoking pack-years was 48 for females and 56 for males.

Researchers conducted regression-based modeling to examine the association between gender and COPD morbidity. Multivariable models were then adjusted for age, race, body mass index, smoking status and predicted FEV₁ percentage.

After analyses were adjusted, researchers found that female gender was independently associated with:

• greater respiratory-specific QoL impairment, with SGRQ scores 4.48 points higher than males
• greater general QoL impairment, with SF-36 scores 17.47 points lower than males
• shorter distances walked during 6MWTs, which was 31.4 meters fewer

Researchers also found that women:

• had higher chances of hypoxemia with 6MWT
• were more likely to be symptomatic, defined by mMRC greater than or equal to 2 or CAT greater than or equal to 10.
• experienced a greater frequency of acute exacerbations than men, with an odds ratio of 1.75
• experienced more severe acute exacerbations than men, with an odds ratio of 1.25

“Our preliminary results, representative of the data available at the time of analysis, add to existing literature by quantifying the extent of COPD morbidity among women and inform our next steps to characterize the role of hormonal factors,” researchers concluded.

Reference

Lambert A, Dieter B, Barjaktarevic I, et al. Women with COPD experience increased symptom burden, frequent and severe exacerbation, and impaired functional capacity as compared to men in SPIROMICS. Presented at 2019 American Thoracic Society International Conference; Dallas, Texas. May 17-22, 2019. www.abstractsonline.com/pp8/#!/5789/presentation/25836. Accessed May 28, 2019. Abstract A5941/202.