This study was a post-hoc analysis of a randomized controlled trial in which males and females with diagnosis of MetS, according to the criteria defined by the National Cholesterol Education Program Adult Treatment Panel III guidelines, were studied. Subjects who met the inclusion criteria were randomly assigned to either curcumin (daily dose of 1 g/day) or a matched placebo for a period of 8 weeks.
One hundred and seventeen subjects were assigned to either curcumin (n = 59) or placebo (n = 58) groups. Within-group analysis revealed significant reductions in serum concentrations of TNF-α, IL-6, TGF-β and MCP-1 following curcumin supplementation (p < 0.001). In the placebo group, serum levels of TGF-β were decreased (p = 0.003) but those of IL-6 (p = 0.735), TNF-α (p = 0.138) and MCP-1 (p = 0.832) remained unaltered by the end of study. Between-group comparison suggested significantly greater reductions in serum concentrations of TNF-α, IL-6, TGF-β and MCP-1 in the curcumin versus placebo group (p < 0.001). Apart from IL-6, changes in other parameters remained statistically significant after adjustment for potential confounders including changes in serum lipids and glucose levels, and baseline serum concentration of the cytokines.
Results of the present study suggest that curcumin supplementation significantly decreases serum concentrations of pro-inflammatory cytokines in subjects with MetS.