The Association Between Blood Mercury Level and Blood Pressure Differs by the Type of Fish Consumed in Children

Abstract

PP-30-134 Background/Aims: The balance of contaminant risk and nutritional benefit from fish consumption is not clear. Mercury exposure, which is related to fish consumptions, has been shown to play a role in blood pressure. The objective was to assess the association of blood mercury levels (BML) with blood pressure (BP) by the type of fish consumed in children. Methods: We assessed BML and BP of ∼3200 children aged 7–9 years from the nationwide cohort study, the Children's HEalth and Environmental Research (CHEER). Children's dietary intake was measured by a food frequency questionnaire, from which the intake frequencies of different types of fish were calculated. Children were dichotomized into 2 groups based on BML and the level of each type of fish consumed. Multivariate analyses were performed to examine the interaction between fish intake and BML on BP. Results: We found a positive association between BML and BP. When we stratified our data by BML and fish intake, log transformed systolic and diastolic BP were higher (P for difference = 0.01, P for interaction = 0.06–0.07) in the high BML group (GM = 3.0 μg/L) than in the low BML group (GM = 1.1 μg/L) among the children with the low level of blue fish intake (<once per week). For the high blue fish intake group, there was no association between BML and BP. Consumption of white and shell fishes did not modify the association of BML with BP. Conclusion: The role of fish in the association between BML and BP depends on the level and type of fish consumed.