The Association Between Serum Magnesium and Premenstrual Syndrome: a Systematic Review and Meta-Analysis of Observational Studies.

A number of studies have assessed the association between serum magnesium (Mg) and premenstrual syndrome (PMS) in different population, but the findings have been inconclusive. Herein, we systematically reviewed available observational studies to elucidate the overall relationship between Mg and PMS. PubMed, Cochrane's library, ScienceDirect, Scopus, Google Scholar, and ISI web of science databases were searched for all available literature until January 2019 for studies evaluating the association between Mg and PMS. The Newcastle-Ottawa Quality Assessment Scale was used to assess the quality of observational studies. A total of 13 studies out of 196 met our inclusion criteria and were included in our systematic review and meta-analysis. There were no associations between serum magnesium and PMS (WMD - 0.04; 95% CI, - 0.14 to 0.06; P = 0.46) during follicular or serum/erythrocyte magnesium (WMD - 0.37; 95% CI, - 1.01 to 0.27; P = 0.25)/(WMD - 0.04; 95% CI, - 0.10 to 0.03; P = 0.26) and during luteal phase except for the sub-group of studies done outside of the US in which recent association became significant and means that serum Mg is lower in PMS subjects. According to what have been discussed, although our study did not show any significant association between serum/erythrocyte Mg and PMS except for serum Mg in luteal phase in the sub-group of studies done outside of the USA, heterogeneity between studies should be taken into accounts when interpreting these results. Additional well-designed clinical trials should be considered in future research to develop firm conclusions on the efficacy of magnesium on PMS.Registration number: CRD42018114473 .