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

Table 3

Prevalence of abnormal values for iron status indicators regardless of inflammation and C-reactive protein (CRP) in preschool Inuit children.

	Mean (SD)	Median (IQR)	Cutoff point	Prevalence of abnormal values; % ()
Hb (g/L)	120.2 (11.0)	120 (114–128)	<110	15.0 (27/180)
MCV (fL)	74.5 (5.7)	75.4 (72.3–77.9)	<72	22.8 (41/180)
MCHC (g/L)	330.0 (17.0)	329 (319–344)	<320	27.7 (49/177)
SI (µmol/L)	8.7 (4.7)	8.0 (5.0–11.0)	<9	54.7 (93/170)
TIBC (µmol/L)	81.3 (13.8)	80.6 (71.3–89.4)	>72	74.1 (126/170)
TS (%)	11.1 (6.5)	10.0 (6.3–14.0)	<16	81.8 (139/170)
SF (µg/L)	24.5 (18.6)	21.0 (11.8–30.0)	<15	32.9 (56/170)
sTfR (mg/L)	2.1 (0.7)	1.9 (1.7–2.3)	>1.95	47.4 (73/154)
sTfR-FI	1.9 (1.8)	1.5 (1.2–1.9)	>1.5	49.7 (74/149)
CRP (mg/L)	5.9 (12.6)	0.9 (0.5–4.8)	>5	24.7 (42/170)

SD: standard deviation; IQR: interquartile range.
Hb: hemoglobin; MCV: mean corpuscular volume; MCHC: mean corpuscular hemoglobin concentration; SI: serum iron; TIBC: total iron binding capacity; TS: transferrin saturation; SF: serum ferritin; sTfR: soluble transferrin receptor; sTfR-FI: soluble transferrin receptor-ferritin index.
Reference sources for the cutoffs were as follows: Hb [19]; MCV [20]; MCHC [21]; SI and TIBC [22, 23]; TS [14, 19, 23]; SF [6, 30]; sTfR [26]; sTfR-FI [18, 27–29]; CRP [7, 31–33].