Hypertension in Relation to Circulating Magnesium Levels: A Systematic Review and Meta-Analysis of Observational Studies

CONTEXT: There was no consistency regarding the findings of preceding studies on the association between magnesium levels and hypertension. OBJECTIVE: The aim of the present systematic review and meta-analysis of observational studies was to investigate the relationship between circulating magnesium concentration and hypertension. DATA SOURCES: To obtain epidemiological studies that investigated the association between circulating magnesium and hypertension, Web of Science (ISI), MEDLINE (PubMed), and Scopus databases as well as Google Scholar were searched up to February 2024, with no time or language restriction. DATA EXTRACTION: Observational studies examined the relationship between hypertension and circulating magnesium levels were included and related data were extracted. DATA ANALYSIS: In total, 3 cohort studies (with 15 730 subjects) and 19 cross-sectional studies (with 42 702 subjects) were included. The combination of 25 effect sizes from 22 studies showed an inverse relationship between circulating magnesium concentration and hypertension (OR = 0.65; 95% CI: 0.56-0.76) by comparing highest versus lowest levels of circulating magnesium concentration. We note, however, that there was a significant heterogeneity between studies (I2 = 81.1%; P < .001). A linear dose-response analysis of 21 eligible studies revealed that each 0.5 mg/dL increase in circulating magnesium concentration was linked to 7% decreased odds of hypertension (OR = 0.93; 95% CI: 0.91-0.95). A nonlinear U-shaped association was also found between circulating magnesium concentration and hypertension (Pnonlinearity = .01): Circulating magnesium levels of between 1.6 and 3.5 mg/dL were associated with a significantly decreased risk of hypertension. CONCLUSION: Circulating magnesium concentration was inversely associated with odds of hypertension in a dose-response manner. Considering the high observed level of heterogeneity, it is necessary to conduct further population-based prospective studies to confirm this finding. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration No. 42024519446.