Effect of Microalgae Arthrospira on Biomarkers of Glycemic Control and Glucose Metabolism: A Systematic Review and Meta-analysis.

Diabetes mellitus and insulin resistance are associated with an increased risk of cardiovascular disease (CVD) incidence and a higher rate of CVD-related death. In this study, the effects of Arthrospira (Spirulina) a blue-green algae supplementation on biomarkers of glycemic control and glucose metabolism has been evaluated. PubMed, Scopus, and ISI Web of Science were searched systematically of English human subjects and PubMed for pre-clinical animal studies (rats and mice) from January 2008 until November 2020. The pooled weighted mean difference (MD) and its 95% confidence interval (CI) were calculated and pooled using a random-effect model. Seven clinical and 27 preclinical studies were included. Pooled results of the clinical studies showed that Arthrospira supplementation significantly reduced the fasting blood sugar (FBS): (0.63- 2.90-) 1.77-, total cholesterol (TC): (0.46- ، 4.61-) 2.54-, triglycerides (TG): (0.89- ، 6.54-) 3.71- and increased the high-density lipoprotein cholesterol (HDL-C): (3.86 ، 0.67) 2.27; however, Arthrospira was not significantly effective in terms of reducing the glycated hemoglobin A1c (HbA1C): (1.04 ، 2.23-) 0.59- and low-density lipoprotein cholesterol (LDL-C). Pooled results of preclinical studies showed that Arthrospira supplementation reduced FBS [-10.31 (-12.49, -8.13)] and HbA1C [-5.12 (-8.06, -2.19)] significantly in diabetic animals. Sub-group analysis of clinical studies showed that intervention duration less than 2 months [-2.52 (-4.37, -0.67)] and the dose less than 2 gram [-3.22 (-5.67, -0.76)] showed significant improvement in terms of reducing the FBS in humans. It can be concluded that Arthrospira can be considered as an effective FBS, TG, TC, and HDL-C adjusting nutraceutical agent for diabetes mellitus. Due to the differences in the results of clinical and animal studies in terms of HbA1c, more studies are needed for a definitive conclusion.