Objective: Retinol-binding protein 4 (RBP4) has recently been reported
to be associated with insulin resistance (IR) and the metabolic
syndrome by a number of researchers in various populations. However,
controversies are present among different studies, which might be due
to the differences between various ethnic, age, and sex groups. This
study aimed to determine whether RBP4 can be assumed as a marker of IR
and the metabolic syndrome in the Iranian obese children. Methods: In
the present longitudinal cross-sectional study, 100 5-17 years old
obese children were recruited from January 1, 2011 to February 1, 2012.
The patients’ information including the demographic variables,
health status and behavior, and daily physical activity were collected.
Moreover, serum RBP4 was measured and correlated with the homeostasis
model assessment of IR index (HOMA-IR), components of the metabolic
syndrome, and lipoprotein metabolism. Findings: The results revealed a
positively significant correlation between RBP4 and the HOMA-IR index
(P=0.02). Partial Spearman test also revealed a significant correlation
between RBP4 plasma concentrations and the components of the metabolic
syndrome, including waist circumference, systolic (but not diastolic)
blood-pressure, and fasting blood sugar (P<0.05). However, no
significant correlation was observed between RBP4 and HDL (P=0.3) as
well as triglycerides concentration (P=0.1). Moreover, plasma RBP4
level gradually increased with the increasing number of the metabolic
syndrome components. Conclusion: Regarding the results of the present
study and previous investigations, RBP4 seems to be a suggestible
predictive marker for both insulin resistance and metabolic syndrome in
Iranian obese children; however, further studies are needed to be
conducted among different ethnicities and age groups in order to
determine the predictive value of this correlation