Effects of Vitamin D on Respiratory Function and Immune Status for Patients with Chronic Obstructive Pulmonary Disease (COPD): A Systematic Review and Meta-Analysis

Abstract

Background. Many studies have demonstrated that vitamin D has clinical benefits when used to treat patients with chronic obstructive pulmonary disease (COPD). However, most of these studies have insufficient samples or inconsistent results. The aim of this meta-analysis was to evaluate the effects of vitamin D therapy in patients with COPD. Methods. We performed a comprehensive retrieval in the following electronic databases: PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang Data, and Chinese Scientific Journals Database (VIP). Two trained reviewers identified relevant studies, extracted data information, and then assessed the methodical quality by the Cochrane risk of bias assessment tool, independently. Then, the meta-analyses were conducted by RevMan 5.4, binary variables were represented by risks ratio (RR), and continuous variables were represented by mean difference (MD) or standardized mean difference (SMD) to assess the efficacy of vitamin D therapy in patients with COPD. Then, publication bias assessment was conducted by funnel plot analysis. Finally, the quality of evidence was assessed by the GRADE system. Results. A total of 15 articles involving 1598 participants were included in this study. The overall results showed a statistical significance of vitamin D therapy in patients with COPD which can significantly improve forced expiratory volume in 1 second (FEV1) (MD: 5.69, 95% CI: 5.01-6.38, P < 0.00001 , I 2 = 51 % ) and FEV1/FVC (SMD:0.49, 95% CI: 0.39-0.60, P < 0.00001 , I 2 = 84 % ); and serum 25 (OH)D (SMD:1.21, 95% CI:1.07-1.34, P < 0.00001 , I 2 = 98 % ) also increase CD3+ Tcells (MD: 6.67, 95% CI: 5.34-8.00, P < 0.00001 , I 2 = 78 % ) and CD4+ T cells (MD: 6.00, 95% CI: 5.01-7.00, P < 0.00001 , I 2 = 65 % ); and T lymphocyte CD4+/CD8+ ratio (MD: 0.41, 95% CI: 0.20-0.61, P = 0.0001 , I 2 = 95 % ) obviously decrease CD8+ Tcells(SMD: -0.83, 95% CI: -1.05- -0.06, P < 0.00001 , I 2 = 82 % ), the times of acute exacerbation (RR: 0.40, 95% CI: 0.28-0.59, P < 0.00001 , I 2 = 0 % ), and COPD assessment test (CAT) score (MD: -3.77, 95% CI: -5.86 - -1.68, P = 0.0004 , I 2 = 79 % ). Conclusions. Our analysis indicated that vitamin D used in patients with COPD could improve the lung function (FEV1 and FEV1/FVC), the serum 25(OH)D, CD3+ T cells, CD4 + T cells, and T lymphocyte CD4+/CD8+ ratio and reduce CD8+ T cells, acute exacerbation, and CAT scores.

[Retracted] The Efficacy and Safety of Budesonide/Glycopyrronium/Formoterol in the Treatment of COPD in the Elderly

“…However, the specific molecular mechanism and functional relationship of aging in the occurrence and the development of chronic obstructive pulmonary disease and pulmonary fibrosis are not completely clear [ 49 ]. Finding these molecular mechanisms and functional relationships may bring hope to cure these diseases [ 50 ]. The present study showed that the effects of BGF did not have significant effects on the death rate, hypertension rate, and pneumonia in patients with COPD.…”

Vitamin D deficiency in chronic obstructive pulmonary disease

“…However, when the COPD RCTs were examined separately, there was no effect of vitamin D supplementation on acute respiratory infection, suggesting this finding likely driven by other patients [29]. A separate meta-analysis found a positive effect of vitamin D supplementation on the rate of COPD exacerbations (relative risk 0.40 95% CI 0.28–0.59, P < 0.00001) [30]. The discrepancies between these two meta-analyses may be explained by a wide variation of replacement strategies, with the latter analysis included studies with higher replacement doses.…”

“…Third, what is the optimum treatment regimen for VDD in COPD patients? The recent meta-analyses described earlier clearly show heterogeneity of doses, intervals, and routes of administration in clinical trial regimens [30]. This likely reflects the lack of consistency in the definitions and goals of various international consensus documents [42].…”

“…A second recent RCT found a significant increase in FEV 1 and forced vital capacity (FVC) after 4 weeks of vitamin D supplementation in combination with an aerobic exercise intervention, but not with vitamin D supplementation alone [33]. Meanwhile, two recent meta-analyses did suggest a benefit: an analysis by Li et al [34] found an overall improvement in FEV 1 and the FEV 1 /FVC ratio despite the inclusion of varying vitamin D treatment doses and regimens, while a more recent analysis by Yang et al [30] confirmed this demonstrating an improvement in the FEV 1 percent predicted of 5.69% with replacement therapy. Both of these meta-analyses had significant statistical heterogeneity in the outcomes, which indicates between-study differences.…”

Retracted: Effects of Vitamin D on Respiratory Function and Immune Status for Patients with Chronic Obstructive Pulmonary Disease (COPD): A Systematic Review and Meta‐Analysis

“…This article has been retracted by Hindawi following an investigation undertaken by the publisher [ 1 ]. This investigation has uncovered evidence of one or more of the following indicators of systematic manipulation of the publication process: Discrepancies in scope Discrepancies in the description of the research reported Discrepancies between the availability of data and the research described Inappropriate citations Incoherent, meaningless and/or irrelevant content included in the article Peer-review manipulation …”