Gender differences in plasma element concentrations and associations between selenoprotein P and iron metabolism in a community-based cohort study

Essential trace elements, such as iron (Fe) and selenium (Se), play physiological roles in our body, whereas environmental toxic metals, such as arsenic (As), cadmium (Cd), and mercury (Hg), are known to be associated with various disease risks. However, the relationship between elements, biochemical parameters, and lifestyle habits based on multi-elemental analysis in healthy individuals has not been fully verified. Multi-elemental analysis is useful for evaluating the change in the concentration of these elements and metals. In the present study using totally 100 µL plasma samples from the Tohoku Medical Megabank (TMM) community-based cohort study (total of 506 specimens), we conducted a multi-elemental analysis to evaluate 14 elements in generally healthy subjects. We further determined Se-transporter selenoprotein P levels using the originally developed ELISA method, since increases and decreases in selenoprotein P levels are associated with various disease risks. Multiple correlation analyses between the obtained measured values and several factors suggest that elements such as Fe, Se, and Hg, as well as selenoprotein P levels, are associated with gender differences. We also found that factors such as Fe, Se, As, Hg, hematocrit value, hemoglobin (Hb) content, and HbA1c are correlated with selenoprotein P levels. Furthermore, correlations between Fe levels and Hb content and between As/Hg and fish consumption were found. These findings demonstrate the suitability of multi-elemental analyses with limited plasma sample amounts, clearly show gender-differentiated elements, and establish a significant relationship between selenoprotein P and Fe metabolism.