Fluoride Exposure and Blood Pressure: a Systematic Review and Meta-Analysis

Fluoride exposure may cause changes in blood pressure, but this conclusion is controversial. Therefore, this meta-analysis aims to investigate the potential relationship between fluoride exposure and blood pressure or hypertension. PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), WANFANG MED ONLINE, and Chinese Scientific Journals Full-Text Databases (VIP) were searched; in addition, two related studies were added manually. In total, 7 observational studies were identified, the pooled odds ratios (ORs) for hypertension between high and reference fluoride exposure groups were calculated, and the pooled standardized weighted mean difference (SMD) of systolic blood pressure (SBP) and diastolic blood pressure (DBP) was estimated using an inverse-variance weighted random-effects model; next, sensitivity analysis and subgroup analysis were used to assess potential sources of heterogeneity; furthermore, publication bias was assessed using the Begg and Egger test. In brief, there were no statistical differences between exposure groups and control groups in terms of blood pressure or hypertension when all included studies considered. However, subgroup analysis indicated that blood pressure will rise with the increase of fluoride exposure concentrations in endemic fluorosis areas. The corresponding pooled SMD estimates were 0.31 (95% CI 0.11, 0.51) and 0.27 (95% CI 0.11, 0.43) for SBP and DBP. Funnel plots suggested no asymmetry. Our findings support the possibility of a positive correlation between fluoride exposure and blood pressure in endemic fluorosis areas. Additional evidence is needed to assess the dose-response relationship between fluoride exposure and blood pressure.