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Table 1 Characteristics of the populations studied

From: Diagnostic utility of zinc protoporphyrin to detect iron deficiency in Kenyan pregnant women

Characteristic All women Women without either inflammation, Plasmodium infection, or HIV infection
n   470   175
Age     
<20 years 20.6% (97) 17.1% (30)
≥20 years 79.4% (373) 82.9% (145)
Gestational age     
13–14 weeks 9.1% (43) 6.3% (11)
15–16 weeks 25.7% (121) 25.1% (44)
17–18 weeks 29.6% (139) 26.3% (46)
19–21 weeks 24.5% (115) 30.3% (53)
22–25 weeks 11.1% (52) 12.0% (21)
Gravidity     
Primigravida 18.1% (85) 17.7% (31)
Secundigravida 19.6% (92) 16.0% (28)
Multigravida 62.3% (293) 66.3% (116)
Plasma CRP concentration, mg/L 4.3 [2.1–10.4] 0  
Plasma AGP concentration, g/L 0.72 [0.60–0.93] 0  
Inflammation     
Plasma CRP concentration ≥10 mg/L 26.8% (126) 0  
Plasma AGP concentration ≥1 g/L 18.1% (85) 0  
Plasma concentrations of CRP ≥10 mg/L, or AGP ≥1.0 g/L 32.3% (152) 0  
HIV infection 21.1% (99)a 0  
Plasmodium infection     
Any Plasmodium infection,b by dipstick or PCR 37.2% (175) 0  
Current or recent P. falciparum infection, by either HRP2- or pLDH-based dipstick 19.5% (91) 0  
P. falciparum, by PCR 34.7% (163) 0  
Haemoglobin concentration, g/L 113.2 (11.4) 115.7 (10.8)
Anaemia (haemoglobin concentration <110 g/L) 37.2% (175) 25.7% (45)
Plasma ferritin concentration, μg/L 13.9 [8.2–29.2] 10.6 [7.0–18.5]
Iron status     
Iron deficient (plasma ferritin concentration <15 μg/L) 52.8% (248) 64.6% (113)
Iron replete (plasma ferritin concentration ≥15 μg/L, without inflammation) 27.2% (128) 35.4% (62)
Uncertain (plasma ferritin concentration ≥15 μg/L, with inflammation) 20.0% (94) 0  
Whole blood ZPP, μmol/mol haem 90 [68–121] 87 [63–121]
Whole blood ZPP >70 μmol/mol haem 73.4% (345) 69.1% (121)
Erythrocyte ZPP, μmol/mol haem 36 [20–66] 42 [20–74]
Erythrocyte ZPP >70 μmol/mol haem 23.4% (110) 28.6% (50)
Erythrocyte ZPP >40 μmol/mol haem 46.4% (218) 52.6% (92)
EP concentration, μg/L 203 [117–428]a 224 [130–476]c
Plasma sTfR concentration, mg/Ld 1.94 [1.48–2.63] 1.87 [1.36–2.62]
Plasma transferrin concentration, g/L 3.12 (0.56) 3.21 (0.54)
Plasma folate concentration, μg/Le 6.91 [5.45–9.39]f 6.55 [5.21–8.87]c
Plasma folate concentration <3 μg/L 0.6% (3/466)f 0.6% (1/174)c
Plasma vitamin B12 concentration, pmol/Lg 425 [311–651]f 413 [307–638]c
Plasma vitamin B12 concentration <150 pmol/L 0.9% (4/466)f 0.6% (1/174)c
Plasma bilirubin concentration, μmol/L 6.9 [4.9–9.4]f 7.1 [4.8–9.4]c
α +-thalassaemia genotype     
Normal 51.2% [109/213]h 48.4% [44]i
Heterozygote 41.3% [88/213]f 42.9% [39]i
Homozygote 7.5% [16/213]f 8.8% [8]i
  1. Values indicate mean (SD), median [25th and 75th percentile] or % (n).
  2. AGP, α 1-acid glycoprotein protein; CRP, C-reactive protein; EP, Erythrocyte protoporphyrin; HRP2, P. falciparum-specific histidine-rich protein-2; pLDH, Plasmodium-specific lactate dehydrogenase; sTfR, Soluble transferrin receptor; ZPP:H, Zinc protoporphyrin:haem.
  3. aMissing values resulted in n =468; bOnly one participant had infection by a Plasmodium species other than P. falciparum; cMissing values resulted in n =174; Reference values d0.8 1.9 mg/L and e2.6 15.4 μg/L; fMissing values resulted in n =466; Reference values g130 700 pmol/L; Missing values resulted in hn =213 and in =91.