The association between vitamin D and COPD risk, severity, and exacerbation: an updated systematic review and meta-analysis
International Journal of Chronic Obstructive Pulmonary Disease, Volume 2016:11(1) Pages 2597—2607, DOI https://doi.org/10.2147/COPD.S101382
Received 26 November 2015, Accepted for publication 5 May 2016, Published 19 October 2016
Authors Zhu M, Wang T, Wang C, Ji Y
Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, People’s Republic of China
Note: It took almost a year to get this paper published
It agrees with many other COPD studies
See also VitaminDWiki
Background: In recent years, the pleiotropic roles of vitamin D have been highlighted in various diseases. However, the association between serum vitamin D and COPD is not well studied. This updated systematic review and meta-analysis aimed to assess the relationship between vitamin D and the risk, severity, and exacerbation of COPD.
Methods: A systematic literature search was conducted in PubMed, Medline, EMBASE, Chinese National Knowledge Infrastructure, Wanfang, and Weipu databases. The pooled risk estimates were standardized mean difference (SMD) with 95% confidence interval (CI) for vitamin D levels and odds ratio (OR) with 95% CI for vitamin D deficiency. Meta-regression and subgroup analyses were performed on latitude, body mass index, and assay method.
Results: A total of 21 studies, including 4,818 COPD patients and 7,175 controls, were included. Meta-analysis showed that lower serum vitamin D levels were found in COPD patients than in controls (SMD: -0.69, 95% CI: -1.00, -0.38, P<0.001), especially in severe COPD (SMD: -0.87, 95% CI: -1.51, -0.22, P=0.001) and COPD exacerbation (SMD: -0.43, 95% CI: -0.70, -0.15, P=0.002).
Vitamin D deficiency was associated with
- increased risk of COPD (OR: 1.77, 95% CI: 1.18, 2.64, P=0.006) and with
- COPD severity (OR: 2.83, 95% CI: 2.00, 4.00, P<0.001)
- but not with COPD exacerbation (OR: 1.17, 95% CI: 0.86, 1.59, P=0.326).
Assay methods had significant influence on the heterogeneity of vitamin D deficiency and COPD risk.
Conclusion: Serum vitamin D levels were inversely associated with COPD risk, severity, and exacerbation. Vitamin D deficiency is associated with increased risk of COPD and severe COPD but not with COPD exacerbation. It is worth considering assay methods in the heterogeneity sources analysis of association between vitamin D deficiency and COPD.