Human RBP4 blocking peptide

Aim. - Retinol-binding protein 4 (RBP4), primarily secreted by liver and adipose tissue, has been linked with non-alcoholic fatty liver disease (NAFLD). However, investigations on the relationships between RBP4 and NAFLD have produced inconsistent results. Therefore, the association between serum RBP4 levels and the development or regression of NAFLD was prospectively investigated. Methods. - A total of 3389 Chinese adults, aged 40-75 years and followed-up for 3.09 years, were included and analyzed in the study. NAFLD was diagnosed by abdominal ultrasonography. Serum RBP4 levels were measured, and their relationship to NAFLD development and regression assessed. Results. - Of the 1318 participants without NAFLD at baseline, 410 developed NAFLD after follow-up. Baseline RBP4 was positively associated with incident NAFLD: the fully adjusted odds ratio (OR) was 2.01 with a 95% confidence interval (CI) of 1.33-3.04 (P = 0.003 for trend). After follow-up, a significant increase in RBP4 levels was observed in participants who developed NAFLD. On the other hand, in 1382 subjects diagnosed with NAFLD at baseline, 339 experienced NAFLD regression after follow-up. Thus, baseline RBP4 was inversely associated with NAFLD regression: the fully adjusted OR was 0.52 with a 95% CI of 0.34-0.80 (P < 0.001 for trend). A significant decrease in RBP4 after follow-up was also noted in participants with NAFLD regression. Conclusion. - Serum RBP4 concentrations are associated with the development and regression of NAFLD, making them a potential novel preventative and therapeutic target in NAFLD management. (C) 2019 Elsevier Masson SAS. All rights reserved.

The association of retinol binding protein-4 (RBP4) with incident type 2 diabetes (T2DM) in Asian Indian middle-aged men with impaired glucose tolerance (IGT) was studied. This was an ancillary analysis of a subsample from a cohort of participants with IGT in a 2 year prospective diabetes prevention program in India. For this analysis, 71 incident T2DM and 76 non-diabetic cases (non-progressors) based on the final glycemic outcome were selected. Baseline serum RBP4 was measured using competitive enzyme immunoassay. Correlations of RBP4 with relevant anthropometric and biochemical variables and also its association with diabetes were assessed using appropriate statistical analyses. Participants who developed T2DM had higher levels of serum RBP4 (21.3 [IQR: 17.7-24.9] mu g/mL) compared with non-progressors (17.3 [IQR: 13.1-21.0] mu g/mL; P=0.001). Levels of RBP4 were lower than in Caucasians. Stepwise linear regression analysis showed that body mass index (BMI), systolic blood pressure, triglycerides, and HbA1c had independent associations with RBP4 levels. Multiple logistic regression analyses showed that RBP4 was independently associated with incident diabetes (odds ratio [OR] [95%confidence interval (CI)]: 1.69 [1.18-2.41]; P=0.004). Adjustment for study group, age, BMI, waist circumference, 2 H plasma glucose, triglycerides, gamma glutamyl transferase, and insulin resistance weakened the significance of its association (OR [95%CI]: 1.65 [1.03-2.66]; P=0.038).The results of this preliminary analyses showed that baseline serum RBP4 levels were independently associated with incident diabetes in Asian Indian men with IGT. It may be used as an additional predictor of future diabetes. (c) 2015 BioFactors, 41(3):160-165, 2015