Serum soluble transferrin receptor concentrations in US preschool children and non-pregnant women of childbearing age from the National Health and Nutrition Examination Survey 2003-2010.
BACKGROUND
Serum soluble transferrin receptor (sTfR) is recommended as a sensitive and accurate measure of iron deficiency (ID) in populations when only a single indicator can be used. The lack of assay standardization and of representative data on the distribution of sTfR in at-risk populations currently limits its utility.


METHODS
Using data from NHANES 2003-2010, we examined the distribution of sTfR and developed assay-specific cutoff values for defining elevated sTfR in 2 US populations groups: children aged 1-5 y (n=2820) and non-pregnant women aged 15-49 y (n=6575).


RESULTS
On average, children had higher geometric mean sTfR concentrations (4.09 mg/l; 95% CI: 4.04-4.14) than non-pregnant women (3.31 mg/l; 95% CI: 3.26-3.35) (p<0.001). Among children, those aged 1-2 y (compared to those aged 3-5 y), boys (compared to girls), and non-Hispanic black (NHB) children (compared to non-Hispanic white (NHW) and Mexican-American (MA) children) had higher sTfR concentrations. Among non-pregnant women, adolescents (15-19 y) had higher sTfR concentrations than adults aged 20-34 y but not compared to adults aged 35-49 y; NHB women (compared to NHW and MA women) and multiparous women (compared to nulliparous women) had higher sTfR concentrations. The derived cutoff values (97.5th percentile in a defined healthy reference population) for defining elevated sTfR in the US were 6.00 mg/l for children 1-5 y and 5.33 mg/l for non-pregnant women 15-49 y.


CONCLUSIONS
A different sTfR cutoff value may be needed in children and non-pregnant women to define ID.
National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention-CDC, Atlanta, GA, USA. zmei@cdc.gov
Zuguo
Z
Mei
Christine M
CM
Pfeiffer
Anne C
AC
Looker
Rafael C
RC
Flores-Ayala
David A
DA
Lacher
Lisa B
LB
Mirel
Laurence M
LM
Grummer-Strawn
D000293:Adolescent; D000328:Adult; D018798:Anemia, Iron-Deficiency / Q000097:blood* / Q000175:diagnosis / Q000208:ethnology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007501:Iron / Q000097:blood*; D000090463:Iron Deficiencies; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D010298:Parity; D011237:Predictive Value of Tests; D011247:Pregnancy; D044469:Racial Groups; D011990:Receptors, Transferrin / Q000097:blood*; D012016:Reference Values; D012995:Solubility; D014481:United States / Q000453:epidemiology
D011990:Receptors, Transferrin; D007501:Iron