Sex-specific environmental and genetic determinants of COPD in middle-aged and older Canadian adults: An analysis of CLSA data
Chronic Obstructive Pulmonary Disease (COPD) is a common respiratory disease in middle-aged and older adults. It is currently the fourth leading cause of death globally and is expected to be the third leading cause of death by 2030.
Recently, a new obstructive airway disease (OAD) known as asthma-COPD overlap (ACO) was described in 2015. In clinical practice, ACO is characterized by presenting features of both asthma and COPD and it is known to have more frequent and severe airflow obstruction, frequent hospitalization and medication usage than other OADs. Many population studies have shown that the prevalence of COPD and ACO is greater in females than in males. The underlying causes and sex differences of COPD and ACO are not fully understood. It is currently believed that both environmental and genetic factors play an important role. However, large genome-wide association studies generally include limited or no information on environmental exposures.
The Canadian Longitudinal Study on Aging (CLSA) has detailed information on many environmental exposures including smoking, pack-years and air pollution information, and also genotype information on more than 794,000 genetic variants for 9,896 individuals aged more than 45 years. This large population study provides a unique opportunity to study the similarities and differences between males and females regarding the complex interplay between environmental and genetic risk factors associated with COPD and ACO, respectively. The results from this study will enhance our understanding of the diseases and have great potential for prevention, intervention and treatment of COPD and ACO.