FST and polycystic ovary syndrome: Follistatin levels were also significantly higher in non-obese PCOS women compared with non-obese controls (random effects, WMD = 0.64 ng/ml; 95% CI = 0.34 to 0.94, P ≤0.001) (S1 Fig and Table 2) and in obese PCOS women vs. obese controls (WMD = 0.58 ng/ml; 95% CI = 0.37 to 0.80, P ≤0.001) (S2 Fig and Table 2).