Background: Retinol binding protein 4 (RBP4) and adiponectin are known to be related with insulin resistance and type 2 diabetes.
Objective and hypotheses: This study was aimed at investigating (RBP4) and adiponectin secretion in obese Korean children and adolescents with newly diagnosed type 2 diabetes (T2DM).
Method: Nine obese children and adolescents with newly diagnosed T2DM (DM group) and ten obese age-matched subjects without T2DM (NDM group) were included. An oral glucose tolerance test (OGTT) was conducted for all patients, and insulin, C-peptide, glucagon, RBP4, and adiponectin were measured.
Results: The mean age of the patients was 13.8±2.0 years, and the mean BMI Z-score was 2.1±0.5. Both groups were comparable in age, sex, pubertal state, BMI Z-score, and waist:hip ratio. The DM group had significantly lower homeostasis model assessment of β and insulinogenic index values (P<0.001). The homeostasis model assessment of insulin resistance was not different between the two groups. Insulin and C-peptide total area under the curve (TAUC) and incremental AUC (iAUC) values were significantly lower in the DM group than in the NDM group (P<0.001). RBP4 levels were higher in NDM group than in the DM group during OGTT (P=0.021). However, there were not significantly different in RBP4 and adiponectin concentration according to time difference in both groups. RBP4 TAUC was significantly higher in the NDM group than in the DM group (P=0.046), while adiponectin TAUC was not different in the two groups. RBP4 iAUC was negatively correlated with BMI (r=−0.46, P=0.49), and adiponectin iAUC was positively correlated with HDL and negatively correlated with total cholesterol (r=0.62, P=0.005; r=−0.5, P=0.03).
Conclusion: Obese Korean children and adolescents with newly diagnosed T2DM had lower insulin levels than those without T2DM. RBP4 levels might be related with serum insulin levels rather than the degree of hyperglycemia.
18 Sep 2014 - 20 Sep 2014