Effects Of Stains On Patients With Chronic Obstructive Pulmonary Disease:a Meta-Analysis

[Objective]As cholesterol-lowering agents, statins have been shown to have pleiotropic effects in recent studies, which have been proved to be beneficial to patients with chronic obstructive pulmonary disease (COPD). However, there are some contradictory results in previous studies, and most studies are of small sample size. So we undertook a meta-analysis of randomized controlled trials (RCTs) that compared statins with conventional therapy in stable patients with COPD to explore the influence on pulmonary function, inflammatory factors, and respiratory symptoms.[Methods]In this meta-analysis, we included randomized controlled studies (RCTs). Searches were conducted on PubMed, Cochrane Library, CNKI, CBM, Wanfang database, Vip database. The following foreign language key terms were used:"statin";"hydroxymethylglutaryl-coA reductaseinhibitors";"chronic obstructive pulmonary disease". Chinese language search terms included "chronic obstructive pulmonary disease";"COPD";"stable";"statin". The RCTs which compared the effect of treatment group (statins combined with conventional therapy) with control group (conventional therapy) for stable COPD patients were identified for their results in the pulmonary function, inflammatory factors, health conditions and prognosis. Two independent reviewers selected independently studies for inclusion, extracted the data, measured the quality and cross-checked. RevMan5.2statistical software was used to analysis the data for clarifying the effect of statins on pulmonary function [forced expiratory volume in one second (FEV1), one second forced expiratory volume in percentage of predicted value (FEV1%pred), FEV1/forced vital capacity ratio (FEV1/FVC),], inflammatory factors[C-Reactive Protein (CRP), Interleukin6(IL-6), Tumor Necrosis Factor-a (TNF-a)], respiratory symptoms, health conditions and prognosis.[Results]This study included10studies,10RCTs, including667patients with stable COPD. Meta-analysis results are as follows.1. Pulmonary functionStatins cannot improve the FEV1, FEV1%pred and FEV1/FVC in stable COPD patients.2. Inflammatory factorsStatins can reduce serum CRP levels (WMD-1.62,95%CI-1.90～-1.34), plasma TNF-a levels(WMD-5.31,95%CI-9.45～-1.17) andserum IL-6levels(WMD-0.46,95%CI-0.89～-0.03) in stable COPD patients.3. Respiratory symptoms, Health conditions and PrognosisIn stable COPD patients, statins can alleviate the clinical symptoms, reduce the degree of dyspnea, inhibit the acute exacerbation and improve the health related Quality of life. However, according the currently RCTs studies, the effects of statins on survival and mortality rate of stable COPD patients cannot be determined.[Conclusion]1. Statins cannot improve the FEV1, FEV1%pred and FEV1/FVC in stable COPD patients and show no significant effect on reversing the decline of the pulmonary function.2. Statins has anti-inflammatory effects which can reduce the serum levels of CRP, TNF-a and IL-6in stable COPD patients. 3. Statins can alleviate the patients’ clinical symptoms, reduce the degree of dyspnea, inhibit the acute exacerbation and improve the health related Quality of life. However, the effects of statins on the survival rate of stable COPD patients are still not very clear.4. Studies selected in this meta-analysis are small, hence more higher quality RCTs are still needed to clarify the effects of statins in the stable COPD patients.