Using Soluble Transferrin Receptor and Taking Inflammation into Account When Defining Serum Ferritin Cutoffs Improved the Diagnosis of Iron Deficiency in a Group of Canadian Preschool Inuit Children from Nunavik

Abstract

The prevalence of iron depletion, iron deficient erythropoiesis (IDE), and iron deficiency anemia (IDA) was assessed in preschool Inuit children using soluble transferrin receptor (sTfR) and traditional indicators of iron status while disregarding or taking inflammation into account when defining SF cutoffs. Iron depletion was defined as follows: (1) SF < 15 μg/L regardless of the C-reactive protein (CRP) level and (2) SF < 15 or <50 μg/L with CRP ≤ 5 or >5 mg/L, respectively. IDE corresponded to iron depletion combined with total iron binding capacity > 72 μmol/L and/or transferrin saturation < 16%. Iron depletion and IDE affected almost half of the children when accounting for inflammation, compared to one-third when the SF cutoff was defined regardless of CRP level (P < 0.0001). The prevalence of IDE adjusted for inflammation (45.1%) was very similar to the prevalence observed when sTfR was used as a sole marker of IDE (47.4%). The prevalence of anemia was 15%. The prevalence of IDA (IDE + hemoglobin < 110 g/L) was higher when accounting for than when disregarding inflammation (8.0% versus 6.2%, P = 0.083). Using sTfR and different SF cutoffs for children with versus without inflammation improved the diagnosis of iron depletion and IDE. Our results confirm that Inuit children are at particularly high risk for iron deficiency.

Anemia, iron status, and associated protective and risk factors among children and adolescents aged 3 to 19 years old from four First Nations communities in Quebec

“…Level of SF is a reliable tool to diagnose ID in the absence of inflammation (hs-CRP ≤ 5 mg/L); therefore, SF < 15 μg/L was used to define ID. In the presence of inflammation (hs-CRP > 5 mg/L), which is frequent among children and in First Nations context, a correction is necessary and ID was diagnosed with SF < 50 μg/L (Turgeon O’Brien et al 2016 ). Since the maximum level of CRP is reached 48 h following an acute inflammation and decreases gradually to less than 10 mg/L in approximately 10 days, a lower cutoff value of 5 mg/L was used (Turgeon O’Brien et al 2016 ).…”

Ferritin Is a Marker of Inflammation rather than Iron Deficiency in Overweight and Obese People

“…Being an acute phase reactant, serum ferritin level is prone to be higher in overweight and obese people, because of a state of subclinical, but generalized inflammation in them [15–17]. Due to this fact, using serum ferritin as a marker of ID or IDA in overweight or obese people is controversial [16, 17].…”

Diagnostic Patterns of Iron Deficiency and Iron Deficiency Anaemia in Children of 6 to 59 Months in Cameroon

“…While using cut-off level of 30 and 50 μg/L experienced for Ferritin level, iron deficiency that varied from 4.2% to 9.6% questioned the real level of Ferritin to be used in children to assess iron shortage. This has been previously raised by Turgeon and collaborators in Canadian children who was proposed to raise the level to 50 μg/L [12] and Phiri's team proposing a value of 273 μg/L in area with high pressure of infection and inflammation [13].…”