Relationship of serum retinol-binding protein 4 with weight status and lipid profile among Korean children and adults

Background/Objectives: Although some studies have suggested that retinol-binding protein 4 (RBP4), a fat-derived adipokine, is positively related to overweight and obesity-related disorders, these claims have been disputed. This study investigated relationships between RBP4 level and weight status and metabolic disorders in a Korean population including confounding factors, age and gender.Subjects/Methods: From 2005 to 2007, we recruited 570 children and 241 of their parents living in Korean urban areas. We analyzed anthropometrical parameters, blood pressure, lipid profiles, and levels of serum glucose, insulin, leptin and RBP4, and estimated dietary intake based on a self-reported 3-day food diary.Results: Levels of RBP4 were high for men (226.2 μg/ml), mid-range among women (143.2 μg/ml) and low among boys and girls (boys 71.4, girls 66.9 g/ml). After adjusting for age, gender differences among adults were consistently maintained (P<0.0001), and gender differences among children were detected minimally (P=0.05). On the basis of Cole's body mass index cutoff points, the prevalence of overweight among children was 19.3%. The prevalence among adults was 32.0%, based on World Health Organization criteria. Overweight children had higher RBP4 concentrations than normal. Overweight women had higher RBP4 levels than those of normal weight. Higher RBP4 levels were observed among overweight men, but the results were not statistically significant. Triglyceride (TG) levels were significantly correlated with RBP4 in all groups.Conclusions: Our results indicate that RBP4 concentrations in a Korean population varied with age, gender and overweight status. TG levels could be strongly correlated with RBP4 concentration.