The acute phase response affected traditional measures of micronutrient status in rural Zambian children during a randomized, controlled feeding trial.
The acute phase response (APR) to infection can alter blood-based indicators of micronutrient status. Data from a 3-mo randomized, controlled feeding trial in rural Zambian children (n = 181, aged 3-5 y) were used to determine the impact of the APR on indicators of vitamin A and iron status using baseline and final blood samples. Concentrations of acute phase proteins were categorized as raised C-reactive protein (CRP; >5 and >10 mg/L) only, both raised CRP and α1-acid glycoprotein (AGP; >1.2 g/L), raised AGP only, and neither CRP nor AGP raised to identify the respective stages of infection: incubation, early convalescence, convalescence, and healthy state. Data were insufficient to examine the incubation stage of infection. A CRP concentration of >5 mg/L was an effective elevation cutoff point in this population to show impact on micronutrient markers. Time did not affect hemoglobin, serum ferritin, or serum retinol concentrations (P > 0.05). During early convalescence, hemoglobin decreased (14-16%; P ≤ 0.05), serum ferritin increased (279-356%; P ≤ 0.05), and serum retinol decreased (20-30%; P ≤ 0.05). Serum retinol concentrations did not change during convalescence; however, hemoglobin remained depressed (4-9%) and serum ferritin was elevated (67-132%) (both P ≤ 0.05). Modified relative dose response values were unaffected by the APR (P > 0.05) but increased between time points (16%; P ≤ 0.05), indicating a decrease in liver vitamin A reserves on the background of a semiannual vitamin A supplementation program. The observed prevalence of anemia and vitamin A deficiency assessed by serum retinol concentration was higher during the APR (P ≤ 0.05). It is important to consider the impact of infection on dietary interventions and to adjust for acute phase proteins when assessing iron status or vitamin A status by serum retinol concentration alone in children.
Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI.
Kara A
KA
Bresnahan
Tropical Diseases Research Center, Ndola, Zambia; and.
Justin
J
Chileshe
Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI.
Sara
S
Arscott
Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI.
Emily
E
Nuss
Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI.
Rebecca
R
Surles
National Food and Nutrition Commission of Zambia, Lusaka, Zambia.
Cassim
C
Masi
Tropical Diseases Research Center, Ndola, Zambia; and.
Emmanuel
E
Kafwembe
Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI sherry@nutrisci.wisc.edu.
Sherry A
SA
Tanumihardjo
D000210:Acute-Phase Reaction / Q000097:blood*; D018798:Anemia, Iron-Deficiency / Q000097:blood; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D002675:Child, Preschool; D005293:Ferritins / Q000097:blood; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D019266:Iron, Dietary / Q000097:blood*; D018977:Micronutrients / Q000097:blood*; D009961:Orosomucoid / Q000378:metabolism; D015995:Prevalence; D012424:Rural Population; D014801:Vitamin A / Q000097:blood*; D014802:Vitamin A Deficiency / Q000097:blood; D015024:Zambia
D015415:Biomarkers; D006454:Hemoglobins; D019266:Iron, Dietary; D018977:Micronutrients; D009961:Orosomucoid; D014801:Vitamin A; D002097:C-Reactive Protein; D005293:Ferritins