Sex-specific characteristics for the coexistence of asthma and COPD in the Canadian population: a cross-sectional analysis of CLSA data

Abstract

Objective: The coexistence of asthma and COPD (asthma + COPD) is a condition found among patients who present with clinical features of both asthma and COPD. Epidemiological evidence points to an increasingly disproportionate burden of asthma + COPD and COPD in females. The objective of this cross-sectional study is to identify female and male-specific epidemiological and clinical characteristics associated with asthma + COPD.

Methods: Baseline data from the comprehensive cohort of Canadian Longitudinal Study on Aging (CLSA) were used in this cross-sectional study which included 30,097 subjects between the ages of 45- and 85-years Participants were categorized into four mutually exclusive groups: asthma + COPD, COPD-only, asthma-only and neither asthma nor COPD.

Results: The prevalence was significantly greater in females than males for asthma + COPD (2.71% vs. 1.41%; p < 0.001), COPD-only (3.22% vs. 2.87%; p < 0.001) and asthma-only (13.31% vs. 10.11%; p < 0.001). The association between smoking and asthma + COPD was modified by age in females. Osteoporosis and underactive thyroid disease were significantly more prevalent in females than in males in asthma + COPD, COPD-only and asthma-only groups. In asthma + COPD group, a greater proportion of respiratory symptoms associated with asthma was observed in females whereas a greater proportion of respiratory symptoms associated with COPD was observed in males. Severity of airway obstruction determined by spirometry measurements was greater in males than females.

Conclusions: In the Canadian adult population, several epidemiological and clinical characteristics in asthma + COPD varied between females and males. The findings in this study will help healthcare professional in the recognition and management of coexisting asthma and COPD in females and males.

Keywords:

• CLSA
• comorbidity
• lung function
• respiratory symptom
• smoking

Acknowledgments

This research was made possible using the data collected by the Canadian Longitudinal Study on Aging (CLSA). Funding for the Canadian Longitudinal Study on Aging (CLSA) is provided by the Government of Canada through the Canadian Institutes of Health Research (CIHR) under grant reference: LSA 94473 and the Canada Foundation for Innovation, as well as the following provinces, Newfoundland, Nova Scotia, Quebec, Ontario, Manitoba, Alberta, and British Columbia. This research has been conducted using the CLSA dataset, Baseline Comprehensive v4.0 (https://www.clsa-elcv.ca/), under Application ID # 19CA006.The CLSA is led by Drs. Parminder Raina, Christina Wolfson and Susan Kirkland.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

This work was supported by Canadian Institutes of Health Research (CIHR).