Role of Retinol-Binding Protein 4 in Obese Asian Indians with Metabolic Syndrome

Retinol-binding protein 4 is an adipocytokine separately implicated in the development of obesity-related insulin resistance and proatherogenic lipid profile, however, its role in humans is unclear. This study was carried out to assess the role of retinol-binding protein 4 as a potential marker of metabolic syndrome in obese Asian Indians (a high-risk population for diabetes). 52 obese (BMI > 23 kg/m(2)) Asian Indians were grouped into those with and without metabolic syndrome based on IDF criteria and compared with healthy controls. The anthropometric and biochemical parameters (fasting blood sugar, lipid profile, serum insulin, high-sensitivity C-reactive protein, and retinol-binding protein 4) were estimated. The obese groups had significantly altered adiposity indices, insulin resistance parameters (fasting blood sugar (only in the metabolic syndrome group), serum insulin, HOMA-IR and QUICKI), index of inflammation (C-reactive protein) and proatherogenic dyslipidemic profile (serum triglycerides, VLDL-cholesterol, and triglyceride/HDL-cholesterol ratio). Retinol-binding protein 4 levels were elevated in the obese groups, but were not significant. Retinol-binding protein 4 levels were correlated with anthropometric parameters and atherogenic lipids, while C-reactive protein was correlated with anthropometric and insulin resistance parameters in the entire group of subjects. Although these correlations were not observed in the obese groups, in the control group, retinol-binding protein 4 was correlated to the lipid parameters and C-reactive protein to adiposity indices. Thus, the role of retinol-binding protein 4 as a potential marker of metabolic syndrome is limited to the prediction of proatherogenic risk among Asian Indians.