Vitamin D deficiency is associated with the severity of COPD: a systematic review and meta-analysis

Abstract

PurposeTo explore the association between host serum 25-hydroxyvitamin D (25(OH)D) and the susceptibility and severity of COPD.MethodsPrevious studies on the association between host 25(OH)D and the susceptibility and severity of COPD were collected on the basis of a systematic literature search of PubMed and Web of Science up to June 2015. Continuous variable data were presented as standard mean difference (SMD) or weighted mean difference with 95% confidence interval (CI). The dichotomous variable data were analyzed as relative ratio (RR) or odds ratio with 95% CI for cohort and case-control studies. A systematic review was conducted to understand the curative and side effects of vitamin D intake.ResultsA total of 18 studies including eight cohort, five case-control, and five randomized studies met the inclusion criteria. The serum level of 25(OH)D in COPD patients was comparable with controls with a pooled SMD of 0.191 (95% CI: −0.126 to 0.508, P=0.237) based on pooled analyses of cohort studies. However, the serum level of 25(OH)D in COPD patients was lower with a pooled SMD of 0.961 (95% CI: 0.476–1.446, P<0.001) compared with controls based on pooled analyses of case-control studies. The deficiency rates of 25(OH)D were comparable between controls and COPD patients with a pooled RR of 0.955 (95% CI: 0.754–1.211, P=0.705) based on analyses of cohort studies, and the same results were observed based on pooled analyses of case-control studies. Interestingly, the deficiency rate of 25(OH)D was significantly lower in moderate or severe COPD patients with a pooled RR of 0.723 (95% CI: 0.632–0.828, P<0.001) compared with that in mild COPD patients. The same results were obtained from the pooled analysis between moderate and severe COPD patients. The four randomized studies showed that vitamin D intake provided benefit for COPD patients.ConclusionLow serum levels of 25(OH)D were not associated with COPD susceptibility, but the high deficiency rate of 25(OH)D was associated with COPD severity. Vitamin D supplementation may prevent COPD exacerbation.

The association between vitamin D and COPD risk, severity, and exacerbation: an updated systematic review and meta-analysis

“…Zhang et al15 just included two studies, and no statistical significance was found in the analysis. Zhu et al16 conducted a meta-analysis of 18 studies. The analysis showed that the serum levels of 25(OH) D were lower in COPD patients and vitamin D deficiency was associated with COPD severity rather than COPD risk.…”

“…However, the conclusion was not definite. Two meta-analyses on the roles of vitamin D in COPD have been conducted 15,16. However, the studies did not include enough articles, did not extract correct data, pooled the levels of vitamin D from serum and plasma, included participants with vitamin D supplement, or did not analyze the sources of high heterogeneity.…”

Osteoporosis Associated with Chronic Obstructive Pulmonary Disease

“…[ 92 93 94 95 ] Moreover, 25(OH)D levels were lower in advanced stages,[ 8 92 93 94 95 ] suggesting a link between COPD severity and vitamin D deficiency. [ 96 ] The exact reason for such a link is unknown, vitamin D deficiency may be caused by decreased sunlight exposure, poor diet and smoking itself [ 97 ] in COPD subjects. It has also been postulated that the vitamin D status may affect COPD development and exacerbations.…”

Vitamin D status is associated with muscle strength and quality of life in patients with COPD: a seasonal prospective observation study

“…Recent meta-analyses have concluded that vitamin D deficiency is directly associated with COPD disease severity and vitamin D supplementation may prevent exacerbations 10–12. It is purported that this association is mediated through the immunomodulatory effects of vitamin D13 by shifting the inflammatory balance from a pro-inflammatory T-helper cell 1 profile toward a more anti-inflammatory T-helper cell 2 profile 14,15.…”