Effects of selenium supplementation on glycemic control in healthy rodents: a systematic review
Selenium supplementation, glucose tolerance, glucose metabolism, insulin, selenoproteins.
In vivo and in vitro studies have shown that selenium supplementation has insulin-mimetic action related to the antioxidant activity of this micronutrient. Otherwise, other studies suggest that the high expression of glutathione peroxidase (GPx) in the face of the ingestion of high doses of selenium. This effect prevents insulin signaling, however resulting in insulin resistance and hyperglycemia. In view of these controversies, developing a systematic review is a strategy to analyze secondary data on the effect of selenium supplementation on markers of glycemic control in animal models, can provides evidence for mechanisms involved. The systematic review registered at PROSPERO (CRD42021212011) will be developed based on Preferred Reporting Items for Systematic Review and Metanalysis (PRISMA). Experimental, randomized or non-randomized trials of healthy animal models (rodents) of both sexes, only supplemented with selenium (inorganic, organic or synthetic compounds), regardless of dose, frequency or route of administration, will be included. Fasting blood glucose will be considered as the primary outcome and insulin concentration, insulin resistance (HOMAIR), selenium concentration and GPx expression as secondary outcomes. The process of search, selection, extraction and quality analysis will be carried out independently, by two reviewers. Divergences will be resolved by a third reviewer. Searches will be conducted in the databases Embase, Scopus, Medline-Pubmed, Web of Science and CINAHL. The analysis of risk of bias and methodological quality of the included studies will be performed by SYRCLE and CAMARADES tools, respectively. The results will be presented with narrative synthesis according to the Synthesis Without Metaanalysis reporting guideline (SWiM). The meta-analysis will be performed depending on the results obtained.