Blood mercury concentration in relation to metabolic and weight phenotypes using the KNHANES 2011-2013 data

We assessed the association of blood mercury concentration with metabolic and weight phenotypes.

Blood mercury concentration, metabolic syndrome components, and body mass index (BMI) were measured in 6006 Korean adults (2963 men, 3043 women, mean age 44.7 ± 14.7 years), using the 2011-2013 Korean National Health and Nutrition Examination Survey data. Metabolic and weight phenotypes were classified based on BMI and metabolic syndrome (MetS) presence as metabolically healthy and normal weight (MHNW), metabolically unhealthy and normal weight (MUNW), metabolically healthy and obese (MHO), and metabolically unhealthy and obese (MUO).

The geometric mean of blood mercury concentration was 3.37 μg/L (95% CI 3.32-3.43). A higher quartile of blood mercury concentration was associated with older age, male sex, higher education, alcohol use, current smoking, low physical activity, greater energy intake, and hypertension history. After adjusting for confounding factors (age, sex, education, income, health behaviors, and energy intake), blood mercury concentration tended to increase across the MHNW, MUNW, MHO, and MUO groups in all subjects and each sex (P for trend < 0.01). Compared to the lowest mercury quartile group, adjusted odds ratios (95% CI) for MHO and MUO in those with the highest mercury quartile were, respectively, 1.67 (1.34, 2.09) and 2.02 (1.59, 2.56) in all subjects: 1.58 (1.25, 1.99) and 1.72 (1.37, 2.16) for men; 1.33 (0.94, 1.88) and 1.90 (1.34, 2.70) for women.

Blood mercury concentration was associated with both metabolic syndrome and obesity, and the association was dose dependent across metabolic and weight phenotypes.