Resumen
La relación molar entre la proteína de enlace de retinol y la transtirretina (RBP:TTR) ha sido propuesta como un método indirecto para evaluar el estado nutricional de vitamina A en presencia de inflamación. Sin embargo, no existen valores de referencia o puntos de corte apropiados para adultos. Por ello, estudiamos la relación RBP:TTR y la concentración de retinol plasmático en 100 adultos sanos y 31 pacientes quirúrgicos sin inflamación. La distribución por percentilos realizada en 99 adultos sanos con retinol plasmático ≥ 0.7 μmoles/l dio por resultado que los percentilos 2.5, 5, 10, 25, 50, 75, 90, 95 y 97.5 fueron 0.24, 0.31, 0.32, 0.41, 0.47, 0.54, 0.67, 0.78 y 0.81, respectivamente. A fin de definir un punto de corte se realizó la curva ROC (receiver operating characteristic curve) sobre el total de individuos estudiados, 11 de los cuales (8.4%) fueron clasificados como deficientes. La curva obtenida mostró un alto grado de convexidad, el área bajo la curva fue de 0.822 (p < 0.001), lo que implica que la relación RBP:TTR guarda estrecha relación con el estado nutricional de vitamina A. Se propone el punto de corte ≤ 0.37 como el que permite alcanzar alta sensibilidad (81.8%), especificidad (79.2%) y valor predictivo (79.4%).
Palabras clave
RBP:TTR; vitamina A; RBP; TTR; adultos
Clasificación en siicsalud
Artículos originales> Expertos de Iberoamérica>
página www.siicsalud.com/des/des039/04810014.htm
Especialidades
Principal: Nutrición
Relacionadas: Diagnóstico por Laboratorio
Enviar correspondencia a:
Zago, Liliana Beatriz,
Patrocinio y reconocimiento
AgradecimientoEste trabajo ha sido financiado mediante subsidios otorgados por la Secretaría de Ciencia y Técnica de la Universidad de Buenos Aires, UBACyT TB068 y B006.
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RBP:TTR RATIO FOR VITAMIN A ASSESSMENT
Abstract
Retinol Binding Protein to Transthyretin molar ratio (RBP:TTR) has been proposed as an indirect method to assess vitamin A status in children when inflammation is present. However, neither reference values nor an appropriate cutoff point are available for adults. To address this problem, RBP:TTR and retinol were studied in 100 healthy adults and 31 low risk surgical patients without inflammation. According to percentile distribution from 99 healthy adults with plasma retinol ≥ 0.7 μmol/l, the 2.5th, 5th, 10th, 25th, 50th, 75th, 90th, 95th and 97.5th percentiles were 0.24, 0.31, 0.32, 0.41, 0.47, 0.54, 0.67, 0.78 and 0.81, respectively. In order to approach a cutoff point, ROC curve (receiver operating characteristic curve) was performed on data from all studied subjects, 11 of whom (8.4%) were classified as deficient. The obtained curve showed a high degree of upward convexity; the area under the curve was 0.822, p < 0.001. According to ROC curve criteria, RBP:TTR ratio showed a good relationship with vitamin A nutritional status. A cutoff point of ≤ 0.37 is proposed, since it allows reaching high sensitivity (81.8%), specificity (79.2%) and predictive value (79.4%).
Key words
RBP:TTR; vitamin A; RBP; TTR; adults
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