title: Determinants of selenium status in healthy adults.
abstract: BACKGROUND
  Selenium (Se) status in non-deficient subjects is typically assessed by the Se contents of plasma/serum. That pool comprises two functional, specific selenoprotein components and at least one non-functional, non-specific components which respond differently to changes in Se intake. A more informative means of characterizing Se status in non-deficient individuals is needed.
  
  
  METHODS
  Multiple biomarkers of Se status (plasma Se, serum selenoprotein P [SEPP1], plasma glutathione peroxidase activity [GPX3], buccal cell Se, urinary Se) were evaluated in relation to selenoprotein genotypes (GPX1, GPX3, SEPP1, SEP15), dietary Se intake, and parameters of single-carbon metabolism in a cohort of healthy, non-Se-deficient men (n = 106) and women (n = 155).
  
  
  CONCLUSIONS
  Plasma Se concentration was 142.0 ± 23.5 ng/ml, with GPX3 and serum-derived SEPP1 calculated to comprise 20% and 34%, respectively, of that total. The balance, comprised of non-specific components, accounted for virtually all of the interindividual variation in total plasma Se. Buccal cell Se was associated with age and plasma homocysteine (hCys), but not plasma Se. SEPP1 showed a quadratic relationship with body mass index, peaking at BMI 25-30. Urinary Se was greater in women than men, and was associated with metabolic body weight (kg0.75), plasma folate, vitamin B12 and hCys (negatively). One GPX1 genotype (679T/T) was associated with significantly lower plasma Se levels than other allelic variants. Selenium intake, estimated from food frequency questionnaires, did not predict Se status as indicated by any biomarker. These results show that genotype, methyl-group status and BMI contribute to variation in Se biomarkers in Se-adequate individuals.
authors.affiliation: Grand Forks Human Nutrition Research Center, USDA-ARS, Grand Forks, ND, USA. gerald.combs@ars.usda.gov
authors.forename: Gerald F
authors.initials: GF
authors.lastname: Combs
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Watts
authors.forename: Matthew I
authors.initials: MI
authors.lastname: Jackson
authors.forename: LuAnn K
authors.initials: LK
authors.lastname: Johnson
authors.forename: Huawei
authors.initials: H
authors.lastname: Zeng
authors.forename: Angela J
authors.initials: AJ
authors.lastname: Scheett
authors.forename: Eric O
authors.initials: EO
authors.lastname: Uthus
authors.forename: Lutz
authors.initials: L
authors.lastname: Schomburg
authors.forename: Antonia
authors.initials: A
authors.lastname: Hoeg
authors.forename: Carolin S
authors.initials: CS
authors.lastname: Hoefig
authors.forename: Cindy D
authors.initials: CD
authors.lastname: Davis
authors.forename: John A
authors.initials: JA
authors.lastname: Milner
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D001835:Body Weight; D015331:Cohort Studies; D004247:DNA / Q000235:genetics; D004032:Diet; D005260:Female; D005492:Folic Acid / Q000097:blood; D005838:Genotype; D005979:Glutathione Peroxidase / Q000097:blood / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D012643:Selenium / Q000097:blood* / Q000652:urine*; D051149:Selenoprotein P / Q000097:blood / Q000235:genetics; D014805:Vitamin B 12 / Q000097:blood
chemical_list: D015415:Biomarkers; D051149:Selenoprotein P; D004247:DNA; D005492:Folic Acid; D005979:Glutathione Peroxidase; D012643:Selenium; D014805:Vitamin B 12