Abstract
BACKGROUND The aim of this study was to investigate the correlations of silent information regulator of transcription 1 (SIRT1) expression, inflammatory factors, and oxidative stress with pulmonary function in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). MATERIAL AND METHODS Bronchoalveolar lavage fluid (BALF) was collected from 188 patients with COPD (83 in stable phase and 105 in acute exacerbation phase) and 56 healthy controls. Subsequently, the SIRT1 expression levels, the IL-6 and IL-8 levels (the representatives of inflammatory factors), and the MDA and SOD levels (indicative of oxidative stress) were detected via enzyme-linked immunosorbent assay. Correlations of SIRT1 expression, inflammatory factors, and oxidative stress with pulmonary function parameters [forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) and FEV1] were measured via Spearman's correlation analysis. RESULTS The levels of inflammatory factors and oxidative stress were elevated and SIRT1 expression remarkably declined in patients with AECOPD compared with those in healthy controls and stable COPD patients (P<0.05). Spearman's correlation analysis revealed that SIRT1 expression, interleukin (IL)-6, and IL-8 were strongly associated with pulmonary function parameters (FEV1/FVC and FEV1) in patients with AECOPD (P<0.001), while no such obvious correlation was observed in stable COPD patients. CONCLUSIONS Oxidative stress and expression levels of inflammatory factors are evidently elevated and SIRT1 expression declines in patients with AECOPD. Moreover, SIRT1 expression is positively associated with pulmonary function parameters, while IL-6 and IL-8 exhibit negative correlations with pulmonary function parameters.