PLOD1 and Insulin resistance: The analysis of several clinical and biochemical variables in the early proliferative phase of the menstrual cycle revealed that PCOS patients showed higher serum levels of androstenedione, estradiol, LH/FSH ratio, and testosterone, as well as free androgen index (FAI) and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) index than control women (Table 1).