The effects of spirulina on glycemic control and serum lipoproteins in patients with metabolic syndrome and related disorders: A systematic review and meta‐analysis of randomized controlled trials

The aim of this systematic review and meta‐analysis was to evaluate the effects of spirulina on glycemic control and serum lipoproteins in patients with metabolic syndrome (MetS) and related disorders. Two independent authors systematically searched online database including EMBASE, Scopus, PubMed, Cochrane Library, and Web of Science from inception until April 30, 2019. The Cochrane Collaboration's risk of bias tool was applied to assess the methodological quality of included trials. The heterogeneity among the included studies was assessed using Cochrane's Q test and I‐square (I²) statistic. Pooling effect sizes from studies showed a significant reduction in fasting plasma glucose (FPG; weighted mean difference WMD]: ?10.31; 95% confidence interval, CI ?16.21, ?4.42]) and insulin concentrations (WMD: ?0.53; 95% CI ?0.62, ?0.44]) following the administration of spirulina. Pooled analysis showed also a significant reduction in total cholesterol (WMD: ?20.50; 95% CI ?38.25, ?2.74]), low‐density lipoprotein cholesterol (LDL‐C; WMD: ?19.02; 95% CI ?36.27, ?1.78]), and very low‐density lipoprotein cholesterol (VLDL‐C) concentrations (WMD: ?6.72; 95% CI ?9.19, ?4.26]) and a significant increase in high‐density lipoprotein cholesterol (HDL‐C) levels (WMD: 1.42; 95% CI 0.16, 2.68]) following spirulina therapy. This meta‐analysis demonstrated the beneficial effects of spirulina supplementation on improving FPG, insulin, total cholesterol, LDL‐C, VLDL‐C, and HDL‐C levels in patients with MetS and related disorders.