Associations between total mercury and methyl mercury exposure and cardiovascular risk factors in US adolescents

Low levels of chronic heavy metal exposure are associated with a range of adverse health effects. However, whether total blood mercury (Hg) and methyl mercury (MeHg) exposure affect risk factors for cardiovascular disease (CVD) in adolescents remains unclear. The associations between CVD risk factors and total blood Hg and MeHg in adolescents were evaluated using data from the National Health and Nutrition Examination Survey (NHANES), 2011-2012. Data for 1129 adolescents (age 12-19 years) who participated in the US NHANES 2011-2012 were analyzed. A multivariate linear regression was performed to investigate the associations between CVD risk factors and blood Hg and MeHg concentrations. We identified a strong positive association between blood Hg and MeHg and total cholesterol in adolescents in adjusted model. No associations with other CVD risk factors were found in the overall population. In the gender-stratified generalized linear models, girls with the highest MeHg levels demonstrated a 4.22% (95% CI 0.80%, 7.76%) greater increase in serum total cholesterol (P for trend = 0.029) when compared with girls with the lowest MeHg levels. Our findings suggest that blood MeHg may be positively associated with total cholesterol in adolescent girls. More research is needed to verify this association and to elucidate its underlying mechanisms.