Prior studies also show that COPD affects other organ systems, as well as the lungs. For example, individuals who smoke and develop COPD further increase their risk of cardiovascular disease.
In an editorial on the research published in the same issue of the journal, David M. Mannino, M.D., of the University of Kentucky Medical Center, wrote: "One explanation for worse survival among women might be that some of the systemic complications of COPD, such as muscle dysfunction or depression, are more common in women and that these lead to worse outcomes."
"In two recently published studies of COPD, women had almost three times the prevalence of depression as men (38 percent versus 13 percent) and twice the prevalence of fat-free body mass depletion (40 percent versus 20 percent). While we do not know whether these complications were increased in the study by Dr. Machado and colleagues, it is plausible that the observed differences may have been related to these or other COPD-related complications that differ between the sexes."
He concluded: "Does sex influence survival in COPD? This is still an open question. This study suggests that women with COPD who are on oxygen may die more quickly than men. Whether this observation holds true in other cohorts with differing severity of COPD is yet to be determined. Careful analysis from both clinical data and observational trials will shed more light on this important question and, it is hoped, provide guidance for how to better intervene in the care of our patients with COPD."