Women May Be Twice as Likely to Develop COPD

A study in European Respiratory Journal from researchers at Sweden’s Lund University is among the first to show that women may be at much greater risk of developing chronic obstructive pulmonary disease than men—perhaps as much as 50% more likely.

For a condition that affects as many patients as does COPD, with a high mortality rate, it is surprising that such a potentially strong correlation between female sex and disease susceptibility hasn’t been definitively made previously. While a few earlier studies did show a potential sex effect, the clinical evidence has been conflicting in some cases, and many of the studies before this one looked only at younger patients and more strongly at the clear correlation between smokers and non-smokers. “With regard to sex as a risk factor for developing COPD, the evidence is not clear-cut and seems to depend on the diagnostic criteria used,” the researchers note.

The current research incorporates a new modern measurement for defining airflow limitation in COPD: Lower Limit of Normal (LLN), which has recently been recommended by the American Thoracic Society and the European Respiratory Society, among others. The results of the study suggest that women’s airways may be more sensitive than men’s. Previous COPD measurement was done with spirometry.

“Other potential mechanisms behind the sex effect may include effects of sex hormones, susceptibility due to dimensional differences, and morphological differences suggesting a difference in the natural history of COPD,” the authors suggest.

The finding will need to be confirmed by further research. Limitations of the study include that it included only post-menopausal females; thus, the results may not translate to younger females. “The observed sex effect could theoretically be affected by higher awareness of COPD in male patients, leading to better treatment and spirometry performance,” the authors noted. “With few incident subjects, the observed effect may possibly be an artefact of natural variability, measurement error and dichotomising a continuous outcome to either obstructive or non-obstructive.”