title: The influence of obesity on blood mercury levels for U.S. non-pregnant adults and children: NHANES 2007-2010.
abstract: BACKGROUND
  In animal studies obesity is associated with higher blood and tissue mercury concentrations; however human studies are lacking. Although the mechanism underlying this association is uncertain, obesity may alter the metabolism and distribution of methylmercury.
  
  
  OBJECTIVE
  We determined whether obesity influenced blood mercury levels, the majority of which was methylmercury, for U.S. non-pregnant adults (≥20 years) and children (2-19 years) after controlling for methylmercury intake through fish and shellfish consumption, and other confounders.
  
  
  METHODS
  We completed secondary data analysis of the National Health and Nutrition Examination Survey (NHANES) (2007-2010) for participants who consumed fish/shellfish within 24h of blood collection for mercury analysis. Weighted least squares regression models related blood mercury levels (the dependent variable) to methylmercury exposure (μg) from fish consumed in the previous 24h, body mass index (BMI) (for adults), BMI z-scores (for children), and other confounders.
  
  
  RESULTS
  In adjusted models, blood mercury levels were inversely correlated with BMI for adults [β, 95% confidence interval (CI)=-0.54 (-0.90, -0.18)]. For children, blood mercury levels were inversely correlated with BMI z-scores but the trend was not significant [β (95% CI)=-0.016 (-0.066, 0.035)]. When obese adults or children were compared with those who were overweight/normal weight, blood mercury averaged 22% lower for obese adults (95% CI: -33%, -8.2%), while blood mercury did not differ significantly for obese children [β (95% CI)=-1.7% (-31%, +39%)].
  
  
  CONCLUSIONS
  After adjusting for the main, if not exclusive, exogenous source of methylmercury exposure (through fish/shellfish intake) and other confounders, our results support potential changes in the metabolism, distribution or excretion of methylmercury with increasing BMI (for adults).
authors.affiliation: Department of Environmental Health Sciences, University of South Carolina, Columbia, SC, USA. Electronic address: rothenbs@mailbox.sc.edu.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Rothenberg
authors.affiliation: Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Korrick
authors.affiliation: Department of Exercise Science, University of South Carolina, Columbia, SC, USA.
authors.forename: Raja
authors.initials: R
authors.lastname: Fayad
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D008297:Male; D008628:Mercury / Q000097:blood*; D008767:Methylmercury Compounds / Q000097:blood*; D008875:Middle Aged; D009749:Nutrition Surveys; D009765:Obesity / Q000097:blood* / Q000139:chemically induced / Q000453:epidemiology*; D017747:Seafood; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D008767:Methylmercury Compounds; D008628:Mercury
keywords: Diet; Fish/shellfish; Metabolism; Methylmercury; Obesity