GC and retinal disorder: There was a decreasing trend in circulating levels of VDBP in relation to retinopathy progression; (LnVDBP (ug/ml): with PDR, 6.1 ± 0.8; NPDR, 6.2 ± 0.8; and without PDR or NPDR, 6.7 ± 1.5 (p = 0.01)).