Impact of phytosterol supplementation on plasma lipoprotein(a) and free fatty acid (FFA) concentrations: A systematic review and meta-analysis of randomized controlled trials

Abstract

Background and aimAlthough some earlier studies have indicated the effect of phytosterol (PS) supplementation on serum lipoprotein(a) (Lp(a)) and free fatty acid (FFA) concentration, findings are still conflicting. We aimed to assess the impact of PS supplementation on serum Lp(a) and FFA concentration through a systematic review and meta-analysis of available RCTs. Methods and resultsWe performed a systematic search of all available RCTs conducted up to 21 February 2019 in the following databases: PubMed, Scopus, and Cochrane. The choice of fixed- or random-effect model for analysis was determined according to the I2 statistic. Effect sizes were expressed as weighted mean difference (WMD) and 95% confidence interval (CI). Pooling of 12 effect sizes from seven articles revealed a significant reduction of Lp(a) levels following PS supplementation (MD: −0.025 mg/dl, 95% CI: −0.045, −0.004, p = 0.017) without significant heterogeneity among the studies (I2 = 0.0%, p = 0.599). Also, PS supplementation significantly lowered FFA (MD: −0.138 mg/dl, 95% CI: −0.195, −0.081, p = 0.000) without significant heterogeneity among the studies (I2 = 0.0%, p = 0.911). The results for meta-regression and sensitivity analysis were not significant. ConclusionThe meta-analysis suggests that oral PS supplementation could cause a significant reduction in serum Lp(a) and FFA.