Forty-two percent of Canadian women with asthma developed COPD as they aged, a condition called asthma and COPD overlap syndrome or ACOS, according to a new study from researchers at the University of Toronto published online in The Annals of the American Thoracic Society.
Though previous studies have also shown an increase in ACOS incidents in women, what the researchers of this study found were possible risk factors that may help understand the disparity in ACOS incidence and mortality between women and men.
The study titled “Asthma and COPD Overlap in Women: Incidence and Risk Factors” collected data for 4,051 women with asthma in Ontario for 14 years from 1992-2015, and the average age at the conclusion of the study was 79. Of the 4,051 women, 1,701 or 42 percent developed COPD.
Utilizing a risk survival model to identify and measure associations between sociodemographic status, lifestyle and environmental risk factors and time to onset of COPD, researchers were able to identify four main risk factors associated with ACOS incidence: low education, high body mass index, rurality and heavy cigarette smoking. Though 38 percent of the women who developed ACOS had never smoked cigarettes, women who had smoked the equivalent of five packs per day for five more or more years, were more likely to develop ACOS than those who smoked less or not at all.
The researchers concluded that individual risk factors, more than environmental factors, play a significant role in development of ACOS in women.