Reviews
Retinol-binding Protein 4 and Diabetes Mellitus: A Review on Current Understanding and Clinical Importance
BE01-BE05
Correspondence
Dr. KM Tullanithi,
Assistant Professor, Department of Biochemistry, Shri Satya Sai Medical College and Research Institute, Chennai-603108, Tamil Nadu, India.
E-mail: tullanithi@gmail.com
The Retinol-binding Protein 4 (RBP4) has evolved as an important metabolic signal associated with insulin resistance and diabetes mellitus. Research shows that RBP4 increases early in metabolic stress and thus a potential marker for identifying individuals at risk for type 2 diabetes, gestational diabetes, and diabetic nephropathy. The present review highlights the RBP4’s biological function, its relationship with different states of glucose intolerance, and its potential clinical utility. RBP4 regulates various metabolic pathways which include impairing Glucose Transporter 4 (GLUT4) translocation, enhancing hepatic glucose production and inducing inflammatory pathways. These molecular effect explain the elevated serum RBP4 level in insulin-resistant states and rises even before the changes in fasting glucose or HbA1c. In type 2 diabetes, elevated RBP4 level associates with insulin resistance, dyslipidaemia, and central obesity. During pregnancy, women with elevated RBP4 in the first trimester develop gestational diabetes later, indicating that metabolic changes begin even before routine screening may detect. In diabetic nephropathy, RBP4 reflects early tubular injury and may rise prior to the onset of microalbuminuria. Currently, RBP4 has been considered as a sensitive marker of early metabolic disturbance and renal stress. Prospective studies with larger cohorts and standardised assay can establish RBP4 as part of multimarker panels for predicting diabetes mellitus and monitoring high-risk pregnancy and early kidney and vascular damage. The present review brings into perspective the biological relevance of RBP4, summarises its clinical correlates, and addresses the key challenges that need to be resolved before this protein finds routine applications in diabetes mellitus management.