The impact of smoking on respiratory rehabilitation efficacy and correlation analysis in patients with chronic obstructive pulmonary disease: a retrospective study.

Abstract

Background: Chronic obstructive pulmonary disease (COPD) was a significant public health concern, with smoking being the primary risk factor for its development and progression. The impact of smoking on respiratory rehabilitation efficacy in COPD patients remains an area of interest and investigation. This study aimed to assess the influence of smoking on the efficacy of respiratory rehabilitation in patients with COPD.

Methods: Data of patients with COPD from October 2015 to October 2023 were retrospectively analyzed in this case-control study. The patients who had previously participated in a pulmonary rehabilitation program were excluded. Pulmonary function, exercise capacity, quality of life, and sleep patterns were evaluated before and after rehabilitation.

Results: A total of 40 patients were included and categorized into non-smoking (n=20) and smoking groups (n=20) based on their smoking history. Before rehabilitation, no significant differences were observed between the groups in forced expiratory volume in one second (FEV₁) (P=0.96), forced vital capacity (FVC) (P=0.97), FEV₁/FVC ratio (P=0.73), maximal voluntary ventilation (MVV) (P=0.69), and diffusing capacity of the lung for carbon monoxide (DLCO) (P=0.63). After rehabilitation, FEV₁ (P=0.02), FVC (P=0.009), FEV₁/FVC ratio (P=0.03), MVV (P=0.004), DLCO (P=0.01), these pulmonary functions for non-smokers were much better than the smokers. Similarly, the non-smoking group exhibited significantly greater improvements in 6-minute walk distance (P=0.03), peak oxygen consumption (VO₂) (P=0.01), Borg scale ratings (P=0.02), St. George's Respiratory Questionnaire (SGRQ) scores (P=0.004), and Medical Research Council (MRC) dyspnea scale scores (P=0.005) compared to the smoking group after rehabilitation. The non-smoking patients have more better quality of life compared to the smokers after rehabilitation, which demonstrated by the quality of life scores and Sleep Quality Score, including somatization (P=0.01), emotion management (P=0.009), role play (P=0.008), cognitive function (P=0.04), return to social function (P=0.01), Sleep Quality Score (P=0.02).

Conclusions: Smoking negatively impacts the efficacy of respiratory rehabilitation in COPD patients, leading to poorer pulmonary function, exercise capacity, quality of life, and sleep patterns.