Essential and toxic metal concentrations in biological samples of multiple sclerosis patients: A systematic review and meta-analysis

The role of trace elements and toxic metals on human health has been extensively discussed concerning disease pathogenesis and risk factors of diseases. In this systematic review and meta-analysis, we aimed to investigate arsenic (As), cadmium (Cd), lead (Pb), iron (Fe), zinc (Zn), and magnesium (Mg) levels in individuals with multiple sclerosis (MS) and healthy controls. We searched different databases/search engines for this systematic review and meta-analysis, including Web of Science, PubMed, Scopus, and Google Scholar, until June 27, 2024. Out of 5466 studies identified, 65 met our eligibility criteria and were included in the systematic review. For the meta-analysis, 58 studies with 10420 participants (5316 multiple sclerosis patients and 5104 healthy controls) had adequate data for inclusion. Results from the pooled data, analyzed using a random-effects model, revealed higher levels of As (Hedge's g = 4.00 μg/l, 95% CI = 2.03 to 5.98, P