Fig. 4

NPY concentration in human follicular fluid of women without PCOS was weakly tended to correlate with BMI. Follicular fluid was collected from single leading follicle at egg-retrieval process and assessed NPY level using a specific ELISA kit. Recruited IVF patients were under 40 years old and had normal body weight (BMI 18.5–24.9). NPY level in follicular fluid of non-PCOS had a significant weak correlation with BMI positively, while those of PCOS did not. Each dot indicates an individual result (non-PCOS, n = 42; PCOS, n = 23) (A, B, C, D), bars indicate mean and SD (A) and regression curve (B, C, D). Data were analyzed by unpaired t test (A) and Pearson’s test (B, C, D)