BackgroundCardiovascular disease is a primary cause of death in patients with chronic obstructive pulmonary disease (COPD). Beta-blockers have been proved to reduce morbidity and improve survival in patients with cardiac diseases. But the effects of beta-blockers on outcomes in patients with COPD remain controversial. The objective of this meta-analysis was to assess the effect of beta-blockers on mortality and exacerbation in patients with COPD.MethodsAn extensive search of the EMBASE, MEDLINE and Cochrane was performed to retrieve the studies of beta-blockers treatment in patients with COPD. The random effects model meta-analysis was used to evaluate effect on overall mortality and exacerbation of COPD.ResultsFifteen original observational cohort studies with a follow-up time from 1 to 7.2 years were included. The results revealed that beta-blockers treatment significantly decreased the risk of overall mortality and exacerbation of COPD. The relative risk (RR) for overall mortality was 0.72 (0.63 to 0.83), and for exacerbation of COPD was 0.63 (0.57 to 0.71). In subgroup analysis of COPD patients with coronary heart disease or heart failure, the risk for overall mortality was 0.64 (0.54–0.76) and 0.74 (0.58–0.93), respectively.ConclusionThe findings of this meta-analysis confirmed that beta-blocker use in patients with COPD may not only decrease the risk of overall mortality but also reduce the risk of exacerbation of COPD. Beta-blocker prescription for cardiovascular diseases needs to improve in COPD patients.

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BackgroundOsteoporosis is one of the systemic features of COPD. A correlation between the emphysema phenotype of COPD and reduced bone mineral density (BMD) is suggested by some studies, however, the mechanisms underlying this relationship are unclear. Experimental studies indicate that IL-1β, IL-6 and TNF-α may play important roles in the etiology of both osteoporosis and emphysema. The OPG/RANK/RANKL system is an important regulator of bone metabolism, and participates in the development of post-menopausal osteoporosis. Whether the OPG/RANK/RANKL pathway is involved in the pathogenesis of osteoporosis in COPD has not been studied.MethodsEighty male patients (current or former smokers) completed a chest CT scan, pulmonary function test, dual x-ray absorptiometry measurements and questionnaires. Among these subjects, thirty patients with normal BMD and thirty patients with low BMD were selected randomly for measurement of IL-1β, IL-6, TNF-α (flow cytometry) and OPG/RANK/RANKL (ELISA). Twenty age-matched healthy volunteers were recruited as controls.ResultsAmong these eighty patients, thirty-six had normal BMD and forty-four had low BMD. Age, BMI and CAT score showed significant differences between these two COPD groups (p < 0.05). The low-attenuation area (LAA%) in the lungs of COPD patients was negatively correlated with lumbar vertebral BMD (r = 0.741; p < 0.0001). Forward logistic regression analysis showed that only LAA% (p = 0.005) and BMI (p = 0.009) were selected as explanatory variables. The level of IL-1β was significantly higher in the COPD patients as compared to the normal controls (p < 0.05), but the difference between the two COPD groups did not reach significance. The levels of IL-6 and TNF-α among the three groups were significantly different (p < 0.05). The level of RANKL and the RANKL/OPG ratio were significantly higher in COPD patients with low BMD compared to those with normal BMD and the normal controls (p < 0.05), and correlated negatively with lumbar vertebral BMD, but positively with LAA%.ConclusionsRadiographic emphysema is correlated with low BMD in current and former smokers with COPD. IL-1β, IL-6, TNF-α, and the osteoporosis-related protein system OPG/RANK/RANKL may have some synergetic effects on emphysema and bone loss in COPD.