title: Sex- and age-differences in blood manganese levels in the U.S. general population: national health and nutrition examination survey 2011-2012.
abstract: BACKGROUND
  Manganese is an essential element, but excessive manganese exposure has neurotoxic effects.
  
  
  OBJECTIVE
  To examine blood manganese levels in the general population with respect to sex, age, race/ethnicity, pregnancy and menauposal status, as well as levels of trace elements in blood.
  
  
  METHODS
  We used data from the National Health and Nutrition Examination Survey, a national survey of U.S. residents (n = 7720 participants, ages 1 to 80 years). General linear models and generalized additive models were used to examine the association between blood manganese concentration and participants' characterisics, accounting for the complex survey design.
  
  
  RESULTS
  Blood manganese levels ranged from 1.6 to 62.5 μg/L, with arithmetic means of 10.6 and 9.2 μg/L for women and men, respectively. The following characteristics were significantly associated with higher blood manganese levels: female sex, younger age, Asian origin, and being pregnant. In addition, there were non-linear relationships between blood manganese levels and cadmium, iron, lead, and mercury levels.
  
  
  CONCLUSIONS
  The higher blood manganese levels observed among females suggest sex-related metabolic differences in the regulation of manganese, and elevated levels among pregnant women suggest an important role of manganese in reproduction. The present study supports the need to take into consideration age- and sex-related differences in blood manganese levels, as well as pregnancy status when examining manganese essentiality or toxicity.
authors.forename: Youssef
authors.initials: Y
authors.lastname: Oulhote
authors.forename: Donna
authors.initials: D
authors.lastname: Mergler
authors.affiliation: Department of Environmental and Occupational Health, Université de Montréal, Montréal, Canada. maryse.bouchard@umontreal.ca.
authors.forename: Maryse F
authors.initials: MF
authors.lastname: Bouchard
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008345:Manganese / Q000097:blood*; D008875:Middle Aged; D009498:Neurotoxins / Q000097:blood*; D009749:Nutrition Surveys; D012737:Sex Factors; D014131:Trace Elements / Q000097:blood*; D014481:United States; D055815:Young Adult
chemical_list: D009498:Neurotoxins; D014131:Trace Elements; D008345:Manganese