Effects of chromium supplementation on inflammatory biomarkers: A systematic review and dose-response meta-analysis of randomized controlled trials

Abstract

IntroductionAccumulating evidence suggests that chromium (Cr) supplementation may prevent inflammation, however, the results have been inconsistent. To derive a more precise estimation of the efficacy of Cr supplementation on inflammatory mediators such as tumor necrosis factor‐alpha (TNF‐α), high-sensitivity C‐reactive protein (hs-CRP), and interleukin‐6 (IL‐6), this systematic review and meta-analysis was performed. MethodsAn advanced search of PubMed and Scopus was conducted from inception to 14 April 2020 to find randomized controlled trials that assessed the effect of Cr supplementation on inflammation among the adult population. ResultsThe search resulted in identifying 10 articles which met the inclusion criteria for the systematic review. Our results indicated that Cr supplementation significantly decreased serum levels of hs-CRP (weighted mean differences (WMD): -0.95 mg/l; 95 % CI, -1.54 to -0.36, P = 0.002). Greater effects on hs-CRP were detected in trials using Cr picolinate and Cr chloride, dosage <300 μg with duration ≤12 weeks. Also, 12 weeks supplementation with Cr dinicocysteinate led to a significant reduction in the level of TNF-α but Cr picolinate did not show significant changes in serum levels of TNF-α. Moreover, both Cr picolinate and Cr dinicocysteinate had no significant differences in the level of serum IL-6 and IL-8. Although, a significant non-linear association was found between serum hs-CRP changes and study duration (Pnon-linearity = 0.03), we did not find any significant association between serum hs-CRP changes and dosage (Pnon-linearity = 0.86) with Cr picolinate supplementation. ConclusionSupplementation with Cr picolinate and Cr chloride at dose <300 μg for ≤12 weeks could significantly decrease serum hs-CRP levels.