Effect of Magnesium Supplementation on Plasma C-reactive Protein Concentrations: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND

Results of previous clinical trials evaluating the effect of magnesium supplementation on inflammatory markers are controversial.

OBJECTIVE

A systematic review and meta-analysis of randomized controlled trials (RCTs) were performed to evaluating the effect of oral magnesium supplementation on plasma C-reactive protein (CRP) concentrations.

METHOD

PubMed-Medline, SCOPUS, Web of Science and Google Scholar databases were searched (from inception to August 09, 2016) to identify RCTs, evaluating the effect of magnesium on CRP levels. A random-effects model and a generic inverse variance method were used to compensate for the heterogeneity of studies. Publication bias, sensitivity analysis, and meta-regression assessments were conducted using standard methods.

RESULTS

Overall, the impact of magnesium supplementation on plasma concentrations of CRP was assessed in 11 studies. Magnesium treatment was not found to significantly affect plasma concentrations of CRP (WMD: -0.11 mg/L, 95% CI: -0.75, 0.52, p=0.727). When the analysis was stratified to compare subgroups of studies in populations with baseline plasma CRP values of ≤ 3 and > 3 mg/L, a significant reduction of CRP values was observed in the latter subgroup (WMD: -1.12 mg/L, 95% CI: -2.05, -0.18, p=0.019) but not in the former group (WMD: 0.61 mg/L, 95% CI: -0.10, 1.32, p=0.090). The difference between subgroups was statistically significant (p=0.004).

CONCLUSION

Results of the present meta-analysis indicated that magnesium supplementation reduces CRP levels among individuals with inflammation (CRP levels > 3 mg/dL). This finding suggests that magnesium supplements may have a beneficial role as an adjuvant for the management of low-grade chronic systemic inflammation.