Background and Objective:
Selenium is a trace element with both nutritional and toxicological properties, depending on the dose and the chemical species. Several studies have shown an association between selenium exposure and cardiovascular risk, focusing on lipid profile and blood pressure. In particular, there is an indication that selenium overexposure may raise the risk of dyslipidemia, but uncertainties still apply to such evidence. The aim of our study is to assess the relation between selenium exposure and the effects on lipid profile in experimental human studies.

Material and Methods:
The protocol registration in PROSPERO has been submitted for publication. We conducted a preliminary literature search in the following databases: PubMed, Web of Science, Embase and Cochrane Library with no language restrictions. We used MeSH terms and keywords related to “selenium”, “lipid profile”, “LDL”, “VLDL”, “HDL”, “cholesterol”, and “randomized clinical trials”. We defined the following inclusion criteria according the PICOS statement: adult population, exposure to selenium through supplementation as specific difference between intervention and control groups and evaluation of internal exposure using blood biomarker (e.g. serum/plasma levels), assessment of lipid profile as outcome, randomized clinical controlled trials as study design.

Results:
In the preliminary search, we found 865 records. After duplicate removal, 622 articles were screened by title and abstract. At this stage, we discarded 565 articles, and we reviewed the full-texts of the remaining 56 records to confirm eligibility. Five articles were additionally found through citation chasing techniques and added to the review. We excluded 29 articles due to missing data about outcome of interest. In total, 27 studies met the inclusion criteria and were could be included.

Conclusions:
The study is currently ongoing and results will be presented during the Congress.