Visfatin and retinol-binding protein 4 concentrations in lean, glucose-tolerant women with PCOS

Since insulin resistance is accepted to be a common feature of polycystic ovary syndrome (PCOS), the exact molecular mechanism(s) involved in glucose and lipid metabolism have been under investigation in the syndrome. Recently, two novel adipokines, namely visfatin and retinol-binding protein 4 (RBP4), have been suggested to play a role in insulin resistance and diabetes. This study sought to determine whether plasma concentrations of visfatin and RBP4 are altered in PCOS by comparing a total of 27 lean, normal glucose-tolerant PCOS patients with 19 age- and body mass index-matched healthy controls. The mean plasma visfatin concentrations were higher in PCOS patients than those in healthy subjects (37.9+/-18.2 versus 19.8+/-17.5, P<0.01), while RBP4 concentrations were similar between the two. Both adipokines were correlated with each other in the whole (r=0.50, P<0.01) and in PCOS (r=0.52, P<0.01) groups but not in controls. The results suggest that lean, glucose-tolerant women with PCOS have increased circulating visfatin and unaltered RBP4 concentrations compared with healthy lean women. In order to clarify overlapping effects and their potential contribution to the pathophysiology of PCOS, further studies are needed.