Daijiworld Media Network - Türkiye

Türkiye, Oct 29: Exposure to both cigarette smoke and biomass smoke is associated with poorer lung function, increased breathlessness and more severe exacerbations among patients with chronic obstructive pulmonary disease (COPD), according to a retrospective observational study conducted in Türkiye.

The study analysed 319 patients with stable COPD treated at two tertiary care centres between January 2024 and August 2025. Of these, 159 were exposed to cigarette smoke alone, 80 to biomass smoke alone and 80 to both sources.

Despite being younger, patients exposed to both cigarette and biomass smoke had significantly poorer respiratory function than those exposed to either source alone. Their mean forced expiratory volume in one second (FEV1), a key measure of lung function, was 48.27 per cent of the predicted value, compared with 55.28 per cent among cigarette smokers and 55.62 per cent among those exposed to biomass smoke alone.

Breathlessness was also more pronounced in the combined-exposure group, with a mean modified Medical Research Council (mMRC) dyspnoea score of 2.18, compared with 1.39 among cigarette smokers and 1.88 among those exposed to biomass smoke.

Patients exposed to both smoke sources experienced an average of 2.18 COPD exacerbations annually, compared with 2.08 among cigarette smokers and 1.88 among those exposed to biomass smoke alone.

Severe exacerbations were also more frequent among patients with combined exposure, averaging 1.78 episodes annually, against 1.39 among cigarette smokers and 1.20 among the biomass-exposed group. Episodes requiring mechanical ventilation or intensive care were significantly more common among patients exposed to both sources of smoke.

After adjusting for age, sex and selected coexisting medical conditions, the researchers found that combined smoke exposure was associated with 89 per cent higher odds of severe COPD exacerbations compared with cigarette smoking alone.

The study also found a higher prevalence of pulmonary hypertension among patients exposed to both cigarette and biomass smoke. The condition affected 22.5 per cent of this group, compared with 10.1 per cent of cigarette smokers and 8.75 per cent of those exposed to biomass smoke alone. After adjustment for selected factors, combined exposure was associated with 2.57 times the odds of pulmonary hypertension compared with cigarette smoking alone.

Chronic respiratory failure was also more common among patients with dual exposure, as reflected in the greater use of long-term oxygen therapy. The proportion receiving such treatment was 26.2 per cent in the combined-exposure group, compared with 17 per cent among cigarette smokers and 11.2 per cent among those exposed to biomass smoke alone.

Bronchiectasis, a condition characterised by permanent widening and damage of the airways, was identified in 52.5 per cent of patients with combined exposure, compared with 20.8 per cent of cigarette smokers.

The findings highlight the importance of assessing both cigarette smoking and household biomass smoke exposure when evaluating patients with COPD. Biomass smoke can arise from burning solid fuels such as wood and crop residues for cooking or heating, potentially exposing people to harmful pollutants.

However, the researchers cautioned that the study's retrospective observational design, possible confounding factors and limitations in measuring smoke exposure meant that the findings could not establish a direct cause-and-effect relationship. Larger prospective studies are needed to determine whether combined exposure independently contributes to COPD progression and to clarify its long-term effects on respiratory health.