COMBINED cigarette and biomass smoke exposure was associated with worse COPD outcomes, including more severe exacerbations.
Patients with COPD exposed to both cigarette and biomass smoke experienced poorer lung function, greater breathlessness, and more frequent exacerbations than those exposed to either source alone, according to a retrospective observational study.
Researchers analyzed 319 patients with stable COPD treated at two tertiary care centers in Türkiye between January 2024 and August 2025. Participants were categorized into cigarette smoking alone (159), biomass smoke alone (80), or combined exposure (80).
Despite being younger, patients with combined exposure had significantly worse respiratory function. Their mean forced expiratory volume in one second (FEV1) was 48.27% of predicted, compared with 55.28% in the smoking group and 55.62% in the biomass group (p=0.003).
Breathlessness was also greater, with a mean modified Medical Research Council dyspnea score of 2.18 versus 1.39 and 1.88, respectively (p<0.001).
Patients exposed to both smoke sources experienced an average of 2.18 annual COPD exacerbations, compared with 2.08 among cigarette smokers and 1.88 among biomass-exposed patients (p=0.041).
Severe exacerbations were more frequent in the combined group, averaging 1.78 annually versus 1.39 and 1.20, respectively (p<0.001). Episodes requiring mechanical ventilation or intensive care were also significantly more common.
After adjustment for age, sex, and selected comorbidities, combined exposure was associated with 89% higher odds of severe exacerbations than cigarette smoking alone (adjusted odds ratio: 1.89; 95% CI: 1.22–2.96).
Pulmonary hypertension affected 22.5% of patients with combined exposure, compared with 10.1% of smokers and 8.75% of biomass-exposed patients. Adjusted odds were also higher in the combined group (adjusted odds ratio: 2.57; 95% CI: 1.28–5.15).
Chronic respiratory failure was more frequent with combined exposure, reflected by greater long-term oxygen therapy use (26.2% versus 17.0% and 11.2%). Bronchiectasis was identified in 52.5% of patients with combined exposure, compared with 20.8% of smokers.
These findings highlight the clinical importance of assessing both cigarette smoking and household biomass exposure when evaluating COPD severity. However, the retrospective design, potential confounding, and exposure measurement limitations prevent causal conclusions. Larger prospective studies are needed to establish whether dual exposure independently contributes to disease progression.
Reference
Yüksel A et al. Clinical outcomes of COPD associated with cigarette smoke, biomass smoke, and combined exposure: A retrospective observational study. Tob Induc Dis. 2026;24. doi:10.18332/tid/231161.
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