title: Elevated blood lead and cadmium levels associated with chronic infections among non-smokers in a cross-sectional analysis of NHANES data.
abstract: BACKGROUND
  Experimental animal studies, in vitro experiments, and clinical assessments have shown that metal toxicity can impair immune responses. We analyzed data from a United States representative National Health and Nutrition Examination Survey (NHANES) to explore associations between chronic infections and elevated blood concentrations of lead and cadmium among non-smoking NHANES participants.
  
  
  METHODS
  NHANES data from 1999 to 2012 were examined and weighted to represent the United States population. Multivariable logistic regression was used to estimate adjusted odds ratios (AOR) and 95 % confidence intervals (CI) for heavy metal associations with seropositivity for Helicobacter pylori, Toxoplasma gondii, and Hepatitis B virus (HBV) infections.
  
  
  RESULTS
  Available 2-year survey cycles for infection seroprevalence varied by pathogen, from 1 to 7 cycles. Available sample size, disease seroprevalence, and participant age range also varied by pathogen of interest. After controlling for demographic characteristics and general health condition, an elevated blood lead level above the survey population median was significantly associated with seropositivity for all three pathogens (AORs = 1.2-1.5). In addition, an elevated blood cadmium level above the median was significantly associated with HBV (AOR = 1.5; 95 % CI = 1.2-2.0) and H. pylori (AOR = 1.5; 95 % CI = 1.2-1.7) seropositivity. Age-specific analyses for H. pylori and T. gondii indicated stronger associations among children under 13 years of age, particularly for lead exposure and H. pylori seropositivity, and weaker associations among those over 35 years of age.
  
  
  CONCLUSIONS
  The results of this cross-sectional human health survey suggest that the immunological effects of lead and cadmium toxicity may be associated with an increased susceptibility to chronic infections.
authors: RTI Health Solutions, 3040 Cornwallis Road, Post Office Box 12194, Research Triangle Park, NC, 27709-2194, USA.|Oak Ridge Institute for Science and Education, Oak Ridge, TN, 37831, USA.
authors: Whitney S
authors: WS
authors: Krueger
authors: United States Environmental Protection Agency, Office of Research and Development, National Health & Environmental Effects Research Laboratory, Environmental Public Health Division, Chapel Hill, NC, 27514, USA. wade.tim@epa.gov.
authors: Timothy J
authors: TJ
authors: Wade
mesh_terms: D000328:Adult; D000368:Aged; D002104:Cadmium / Q000097:blood*; D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D004785:Environmental Pollutants / Q000097:blood*; D005260:Female; D016481:Helicobacter Infections / Q000139:chemically induced* / Q000453:epidemiology; D016480:Helicobacter pylori / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D012959:Socioeconomic Factors; D014481:United States; D055815:Young Adult
chemical_list: D004785:Environmental Pollutants; D002104:Cadmium