The severity of non-smoking chronic obstructive pulmonary disease is correlated with biomass fuel exposure and COPD assessment test score.

Abstract

Tobacco smoking is an established risk factor for chronic obstructive pulmonary disease (COPD). Current evidence suggests that non-tobacco-related risk factors vary geographically and are less understood than smoking. This study aims to compare the risk factors, symptoms, and clinical features of smoking (S-COPD) and non-smoking (NS-COPD) in a COPD population. In this retrospective cross-sectional study, 489 COPD patients were screened. Data on socio-demographics, smoking and medical history, other risk factors, symptoms, and clinical characteristics including COPD Assessment Test (CAT) score, and Modified Medical Research Council (mMRC) Dyspnea Scale were examined. Of the total selected 416 COPD patients, 35.34% were NS-COPD while 64.66% were S-COPD. S-COPD was predominant in males, whereas NS-COPD was predominant in females (P < 0.0001). In NS-COPD, biomass fuel exposure was a major risk factor (P < 0.0001), and 61% of subjects had a biomass fuel exposure index of >60. In bivariate and multivariate analyses, no risk factors were correlated with forced expiratory volume in 1 second (FEV1)% predicted, while among clinical features, duration of illness (P = 0.001) was correlated with lower values of FEV1 in the multivariate table of S-COPD. In the multivariate analysis, biomass fuel exposure (P = 0.039) and CAT score (P < 0.0001) were correlated with FEV1(%) in NS-COPD. Biomass fuel exposure is a substantial risk factor for NS-COPD and was correlated with FEV1(%) predicted. In addition, the CAT score correlated with disease severity in patients with NS-COPD. The development of COPD in non-smokers is being recognized as a separate phenotype and it should be managed according to risk factors.