Is serum retinol binding protein-4: A predictor for diabetes in genetically high risk population?

Retinol binding protein-4 (BP-4) a new adipocytokine, specifically binds to retinol, through experimental studies, reported its link between obesity and insulin resistance (IR). But till date no studies are available on influence of genetic predisposition of diabetes on RBP-4 expression. Hence, we aimed to study the influence of genetic predisposition of diabetes on the serum RBP-4 and its role in development of IR and diabetes in genetically high risk population.

Healthy non diabetic individuals (age 18 to 22) were grouped into Group I: Control (n = 81), whose parents are non diabetic, non hypertensive and does not have any family history of coronary heart diseases. Group II: (n = 157) with one of their parents diabetic and Group III: (n = 47) with both parents diabetic. In all the participants, we estimated fasting serum RBP-4, insulin and glucose. Homeostasis model for assessment-insulin resistance (HOMA-IR) and homeostasis model for assessment-beta cell dysfunction (HOMA-B) were calculated from fasting serum insulin and glucose levels.

In this study, we observed significantly higher RBP-4 levels 12.71 ± 2.3 in Group-II and 13.25 ± 2 in Group-III, respectively when compared to Group-I 11.4 ± 1.8 (P < 0.01). RBP-4 showed a significantly strong positive correlation with plasma insulin, glucose and HOMA-IR in genetically high risk population (group II and III) P < 0.01. Linear regression analysis revealed a strong positive association of RBP-4 with parental diabetes even after adjusting for BMI, age and sex (OR 1.53, 95% CI 1.089-1.40).

Higher serum RBP-4 and its positive correlation with Insulin, glucose, and HOMA-IR in healthy non diabetic participants of genetically high risk population, indicating its role as predictor for the onset of diabetes in coming future.