title: Plasma retinol-binding protein predicts plasma retinol concentration in both infected and uninfected Cameroonian women and children.
abstract: Variation in the relationship between plasma retinol-binding protein (RBP) and retinol (ROH) has implications for vitamin A (VA) status assessment using RBP. Our objectives were to identify factors affecting the RBP:ROH relationship and to derive and evaluate population-specific RBP cutoffs for VA deficiency (VAD) in Cameroon. Plasma RBP, C-reactive protein (CRP), α1-acid-glycoprotein (AGP), and ROH concentrations were compared in a subsample of women 15-49 y (n = 121) and children 12-59 mo (n = 123) included in a national survey conducted in 2009. Plasma RBP and ROH were highly correlated (r = 0.94 for women; r = 0.96 for children; P < 0.001). Pregnancy and lactation altered the RBP:ROH relationship in women, but obesity, elevated CRP and AGP, age, and VA status did not. Among children, age altered the RBP:ROH relationship, but sex, stunting, VA status, and elevated CRP and AGP did not. Cutoffs for VAD derived using regression analysis were <1.17 μmol RBP/L for women (corresponding to <1.05 μmol ROH/L) and <0.83 μmol RBP/L for children (corresponding to <0.70 μmol ROH/L). The sensitivity and specificity of derived cutoffs were 81.8 and 93.0% for women and 94.7 and 88.9% for children, respectively. The infection-adjusted prevalence of low VA status (<1.17 μmol RBP/L) was 21.9% (95% CI = 18.7-25.0%) among women. Among children, the infection-adjusted prevalence of VAD (<0.83 μmol RBP/L) was 35.0% (95% CI = 31.1-39.0%). In conclusion, VAD remains a public health problem in Cameroon. The RBP:ROH relationship should be considered in surveys using RBP to assess VA status, and use of population-specific cutoffs may be advisable.
authors: Program in International and Community Nutrition, Department of Nutrition, University of California, Davis, CA, USA.
authors: Reina
authors: R
authors: Engle-Stone
authors: Marjorie J
authors: MJ
authors: Haskell
authors: Alex Ongla
authors: AO
authors: Ndjebayi
authors: Martin
authors: M
authors: Nankap
authors: Juergen G
authors: JG
authors: Erhardt
authors: Marie-Madeleine
authors: MM
authors: Gimou
authors: Kenneth H
authors: KH
authors: Brown
mesh_terms: D000293:Adolescent; D000328:Adult; D000886:Anthropometry; D002097:C-Reactive Protein / Q000032:analysis / Q000378:metabolism; D002163:Cameroon / Q000453:epidemiology; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D016014:Linear Models; D008875:Middle Aged; D009752:Nutritional Status; D054839:Retinol-Binding Proteins, Plasma / Q000032:analysis* / Q000378:metabolism; D012680:Sensitivity and Specificity; D012959:Socioeconomic Factors; D014801:Vitamin A / Q000097:blood* / Q000378:metabolism*; D014802:Vitamin A Deficiency / Q000097:blood / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D054839:Retinol-Binding Proteins, Plasma; D014801:Vitamin A; D002097:C-Reactive Protein