Demystifying COPD in never-smokers

In never-smokers, chronic obstructive pulmonary disease (COPD) may not simply be a milder form of smoking-related disease, according to a study published in BMJ Open Respiratory Research. Instead, it may represent a distinct clinical phenotype requiring a specific approach to management.Although smoking remains the leading risk factor for chronic obstructive pulmonary disease (COPD), the condition can also develop in people who have never smoked. Individuals exposed to air pollution or secondhand smoke are particularly at risk.Never-smokers with COPD generally have fewer symptoms, less severe airflow limitation and better overall health than former or current smokers with COPD.However, they also have a distinct symptom profile and biomarkers that set them apart from smokers with COPD.Researchers have gained a clearer picture of this patient population through an analysis of a population-based cohort, the Swedish CArdioPulmonary bioImage Study (SCAPIS).Often excluded from clinical trials, these patients remain understudied and poorly understood. “Since some clinical features seem to differ from smoking-related COPD, there is a need to increase the knowledge of clinical characteristics, prognosis, causal factors and disease mechanisms in this group, as they might benefit from other treatment strategies than individuals with smoking-related COPD,” the Swedish researchers wrote.Airborne allergensThe researchers compared just over 150 never-smokers with COPD with four control groups: never-smokers with normal lung function, smokers with normal lung function, former smokers with COPD and current smokers with COPD.Overall, never-smokers with COPD appeared to have greater sensitivity to airborne allergens, as well as higher fractional exhaled nitric oxide (FeNO) levels than all other groups studied.Their eosinophil counts were slightly higher than those of never-smokers with normal lung function (0.15 × 10⁹/L versus 0.13 × 10⁹/L), but similar to those of smokers with or without COPD.White blood cell counts were also slightly higher among never-smokers who had developed COPD than among healthy never-smokers. However, these counts remained considerably lower than those observed in smokers with COPD and even smokers without COPD, suggesting that smoking has a greater influence on white blood cell counts than the disease itself.Wheezing, the most common respiratory symptom among never-smokers with COPD, was reported by nearly half of the individuals in this cohort. However, productive cough was less common among never-smokers with COPD than among smokers with COPD.Asthma as a risk factor?Never-smokers with COPD reported a higher prevalence of asthma than never-smokers without COPD, but that is not the whole story.“As many as 60% of never-smokers with COPD did not report a previous diagnosis of asthma, which indicates that previous asthma can only partially explain COPD in never-smokers,” the study authors noted.Moreover, even after participants with asthma were excluded, never-smokers with COPD still had more wheezing and coughing, as well as higher FeNO levels, than healthy never-smokers.Reference:Sönnerfors P, Jacobson PK, Andersson A, Bjermer LH, Blomberg A, Blomqvist H, et al. Characterisation of chronic obstructive pulmonary disease (COPD) in never-smokers and ever-smokers from a population-based cohort. BMJ Open Respiratory Research. 2026;13:e003578.This article has been translated from its original French and first appeared on our sister site Profession Santé.

Demystifying COPD in never-smokers

Register for free access or login.

Related Topics