Estimation of the effect of the acute phase response on indicators of micronutrient status in Indonesian infants.
Level 3 - non-randomized controlled study
Observational analysis of biomarker relationships nested within a randomized controlled trial
PubMed 12368396 · doi:10.1093/jn/131.10.3061
What was done
Relationships between the acute phase response and indicators of iron, zinc, and vitamin A status were analyzed in 418 Indonesian infants who completed a 6-month randomized, double-blind, placebo-controlled trial of iron, zinc, and/or beta-carotene. The acute phase response was evaluated via C-reactive protein (CRP > 10 mg/L), alpha(1)-acid glycoprotein (AGP > 1.2 g/L), or both, alongside alpha(1)-antichymotrypsin (ACT).
What was found
Independent of supplementation, an acute phase response significantly shifted micronutrient biomarkers compared to infants without inflammation: - Plasma ferritin was higher by 15.7 µg/L (raised AGP) to 21.2 µg/L (raised CRP and AGP) (P < 0.001). - Plasma retinol was lower by 0.07 µmol/L (raised AGP, P < 0.05) to 0.12 µmol/L (raised CRP, P < 0.01). - Plasma zinc was lower by 1.49 µmol/L (raised AGP, P < 0.01) to 1.89 µmol/L (raised CRP and AGP, P < 0.05). - Hemoglobin and modified relative dose response were unaffected. - Consequently, iron deficiency anemia was underestimated by >15%, and vitamin A deficiency was overestimated by >16% in infants with elevated acute phase proteins.
Why it matters
Standard circulating indicators for iron, vitamin A, and zinc are systematically skewed by infection-induced inflammation. Failure to account for the acute phase response leads to misclassification of deficiency prevalence in pediatric populations.
Limits
The findings are derived from a single cohort of Indonesian infants, which may not generalize to other age groups or settings. The abstract does not characterize the underlying clinical causes of infection or inflammation.
Cited by
- supports During an acute-phase response, the liver decreases production of albumin, increases production of C-reactive protein (CRP), and reduces circulating levels of iron and zinc.