Huang R, Yin S, Ye Y, et al. - Researchers intended to determine if there is a connection between circulating retinol binding protein 4 (RBP4) levels and β-cell function across the spectrum of glucose tolerance from normal to overt type 2 diabetes. In total, 291 patients (aged 35 to 60) with normal glucose tolerance (NGT), newly diagnosed impaired fasting glucose or glucose tolerance (IFG/IGT), and type 2 diabetes were screened by a standard 2-h oral glucose tolerance test with the use of traditional measures to evaluate β-cell function. Seventy-four patients were recruited for an oral minimal model test from these participants, and β-cell function was evaluated with model-derived indices. Findings suggested an inverse and independent association of circulating RBP4 levels with β-cell function across the spectrum of glycemia, providing another possible explanation of the linkage between RBP4 and the pathogenesis of type 2 diabetes.