Potential for misclassification of micronutrient status in children participating in a Head Start program.
OBJECTIVE
To evaluate relations among measures of iron and zinc status, C-reactive protein (CRP), and leukocytes in low-income children participating in the Head Start program.


METHODS
Cross-sectional correlational study with samples collected at Head Start centers in May 2003.


METHODS
Forty-seven children (aged 3 to 5 years) attending Head Start centers in three rural communities.


METHODS
Zinc, ferritin, CRP, and complete blood count were analyzed in nonfasting blood samples.


METHODS
Correlations were computed among leukocyte levels, CRP levels, and measures of micronutrient status. Children having two abnormal measures (ie, leukocytes and CRP) were compared by univariate analysis of variance with children having zero or one abnormal measure.


RESULTS
Most (72%) of the children had elevated CRP levels. Four percent were anemic (hemoglobin<11.0 g/dL [<110 g/L]); 11% had low iron stores (serum ferritin<or=15 ng/mL [<or=33.7 pmol/L]); and 77% had low iron stores when a reference value that accounts for the presence of infection was used (serum ferritin<or=30 ng/mL [<or=67.4 pmol/L]). Twenty-one percent had low plasma zinc levels. Children with two measures that indicated infection had higher serum ferritin and lower plasma zinc levels than children with zero or one indicator of infection.


CONCLUSIONS
The link between measures of infection and serum ferritin levels suggests low-income preschool children with low iron stores are not identified by the <or=15 ng/mL (<or=33.7 pmol/L) criterion. The link between zinc and infection suggests possible overestimations of zinc deficiency in low-income children. Thus, in this population, the presence of infection (as indicated by CRP levels and leukocyte counts) should be determined to assess micronutrient status.
Droke
Elizabeth A
EA
Department of Nutrition, Food Science, and Hospitality, South Dakota State University, Brookings 57007, USA. elizabeth.droke@sdstate.edu
Kennedy
Tay Seacord
TS
Hubbs-Tait
Laura
L
D000704:Analysis of Variance; D018798:Anemia, Iron-Deficiency / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood; D001772:Blood Cell Count; D002097:C-Reactive Protein / Q000032:analysis*; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D018479:Early Intervention, Educational; D005260:Female; D005293:Ferritins / Q000097:blood* / Q000172:deficiency; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D007239:Infections / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D008297:Male; D018977:Micronutrients / Q000097:blood* / Q000172:deficiency; D015596:Nutrition Assessment; D009752:Nutritional Status; D009825:Oklahoma / Q000453:epidemiology; D011203:Poverty; D012016:Reference Values; D012423:Rural Health; D015032:Zinc / Q000097:blood* / Q000172:deficiency
D015415:Biomarkers; D018977:Micronutrients; D002097:C-Reactive Protein; D005293:Ferritins; D015032:Zinc