RBP4 and type 2 diabetes mellitus: Given the linear association, we also estimated the risk of type 2 diabetes associated with every 1-log μg/mL increment in RBP4 levels, and the OR (95% CI) in model 2 was 1.38 (0.71–2.65) in the whole study population, 0.63 (0.21–1.84) in men and 2.78 (1.09–7.14) in women.