RETINOL-BINDING PROTEIN-4 AND INSULIN RESISTANCE IN GLUCOSE INTOLERANT OBESE PATIENTS

Abstract

Objective: Obesity associated insulin resistance is a major risk factor for type 2 diabetes and
cardiovascular disease. The disturbances of adipokines secretion are associated with the pathogenesis of
insulin resistance and type 2 diabetes. Retinol-binding protein-4 (RBP4), a new adipokine, was recently
reported to provide a link between obesity and insulin resistance. The aim of this study was to study the
relation between retinol-binding protein 4 and insulin résistance in obese patients with or without glucose
intolerance. Research Design And Methods: We studied from august 2008 to august 2010, The study
population included 100 subjects, 20 of them were healthy lean subjects (control group) and 80 obese
patients (their BMI were >30) and they were divided into three groups According to glucose tolerance:
normal glucose tolerance (NGT; n = 20), impaired glucose tolerance (IGT; n = 20), and type 2 diabetes (n
= 40). Plasma RBP4 concentrations were compared with various parameters related to insulin resistance
.Insulin resistance and 4 cell function, were assessed by using the homeostasis model.
Results: Plasma RBP4 concentrations were higher in obese groups As compared to lean group. Plasma
RBP4 concentrations were higher in IGT (23.78±SD 10.57) and diabetic (26.3±SD 10.0) patients as
compared to lean (6.12±SD 1.03) and NGT (16.64±SD 8.04) with more significant changes in diabetic
group. However, no difference was found between plasma RBP4 concentrations in the IGT and type 2
diabetic groups. Plasma RBP4 concentrations were found to be correlated with Systolic and diastolic
blood pressure, BMI .while Plasma RBP4 concentrations were not correlated with Age and sex .Of
these, BMI, fasting serum insulin, fasting plasma glucose levels and HOMA.IR were found to be
independent determinants of plasma RBP4 concentrations. Conclusions: Plasma RBP4 concentrations
were found to be elevated in obese subjects with IGT or type 2 diabetes with more significant changes in
diabetic group and to be related to various clinical parameters known to be associated with insulin
resistance.
Keywords: Adipocyte, adipokines, insulin resistance, homeostasis model.