RBP4 and Insulin resistance: In 29 AV patients and 29 healthy volunteers, body mass index (BMI) and body fat mass (BFM), lipid, adiponectin, leptin, resistin, retinol binding protein-4 (RBP4), and insulin levels were measured and insulin resistance was assessed by HOMA-IR index in serum samples taken twice from patients before and after isotretinoin treatment.