The relative dose response test based on retinol-binding protein 4 is not suitable to assess vitamin A status in very low birth weight infants.
Neonatology
; 105(2): 155-60, 2014.
Article
in En
| MEDLINE
| ID: mdl-24356375
ABSTRACT
BACKGROUND:
The relative dose response (RDR) test, which quantifies the increase in serum retinol after vitamin A administration, is a qualitative measure of liver vitamin A stores. Particularly in preterm infants, the feasibility of the RDR test involving blood is critically dependent on small sample volumes.OBJECTIVES:
This study aimed to assess whether the RDR calculated with retinol-binding protein 4 (RBP4) might be a substitute for the classical retinol-based RDR test for assessing vitamin A status in very preterm infants.METHODS:
This study included preterm infants with a birth weight below 1,500 g (n = 63, median birth weight 985 g, median gestational age 27.4 weeks) who were treated with 5,000 IU retinyl palmitate intramuscularly 3 times a week for 4 weeks. On day 3 (first vitamin A injection) and day 28 of life (last vitamin A injection), the RDR was calculated and compared using serum retinol and RBP4 concentrations.RESULTS:
The concentrations of retinol (p < 0.001) and RBP4 (p < 0.01) increased significantly from day 3 to day 28. On day 3, the median (IQR) retinol-RDR was 27% (8.4-42.5) and the median RBP4-RDR was 8.4% (-3.4 to 27.9), compared to 7.5% (-10.6 to 20.8) and -0.61% (-19.7 to 15.3) on day 28. The results for retinol-RDR and RBP4-RDR revealed no significant correlation. The agreement between retinol-RDR and RBP4-RDR was poor (day 3 Cohen's κ = 0.12; day 28 Cohen's κ = 0.18).CONCLUSION:
The RDR test based on circulating RBP4 is unlikely to reflect the hepatic vitamin A status in preterm infants.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Vitamin A
/
Vitamin A Deficiency
/
Infant, Very Low Birth Weight
/
Clinical Laboratory Techniques
/
Retinol-Binding Proteins, Plasma
/
Infant, Premature, Diseases
Type of study:
Diagnostic_studies
/
Evaluation_studies
/
Qualitative_research
Aspects:
Patient_preference
Limits:
Female
/
Humans
/
Male
/
Newborn
Language:
En
Journal:
Neonatology
Journal subject:
PERINATOLOGIA
Year:
2014
Document type:
Article
Affiliation country:
Alemania