Cut-off values of blood mercury concentration in relation to increased body mass index and waist circumference in Koreans.

Blood mercury (methyl-mercury) from environmental exposure may be related to inflammation in our body. We investigated the cut-off values of blood mercury concentration in relation to increased body mass index (BMI) and waist circumference. On the basis of data obtained from the Korea National Health and Nutrition Examination Survey (KNHANES, 2008-2012), 11,159 subjects (5543 males and 5616 females) were analyzed cross-sectionally. Partial correlation, linear regression, and analysis of covariance (according to the mercury quartile) tests were performed to evaluate the relationship between blood mercury and BMI or waist circumference. In addition, we determined the cut-off values of blood mercury concentration in relation to increased BMI and waist circumference in both genders. Mean values of blood mercury concentration were 5.07 ± 0.07 μg/L in males and 3.59 ± 0.04 μg/L in females. After log transformation of blood mercury, significant (p < 0.001) correlation was found between blood mercury concentration and BMI or waist circumference. BMI and waist circumference showed a significant and gradual increase as mercury quartile increased in both genders. Blood mercury concentration was weakly but significantly (p < 0.001) associated with BMI and waist circumference. Cut-off values of blood mercury concentration correlated with increased BMI and waist circumference were around 3.95 μg/L in males and 3.40 μg/L in females.