Pigment epithelium-derived factor (PEDF) is upregulated in obese rodents and is involved in the development
of insulin resistance (IR). We aim to explore the relationships between PEDF, adiposity, insulin sensitivity, and
cardiovascular risk factors in obese women with polycystic ovary syndrome (PCOS) and weight-matched controls
and to examine the impact of endurance exercise training on PEDF. This prospective cohort intervention study was
based at a tertiary medical center. Twenty obese PCOS women and 14 non-PCOS weight-matched women were
studied at baseline. PEDF, cardiometabolic markers, detailed body composition, and euglycemic–hyperinsulinemic
clamps were performed and measures were repeated in 10 PCOS and 8 non-PCOS women following 12 weeks
of intensified aerobic exercise. Mean glucose infusion rate (GIR) was 31.7% lower (P = 0.02) in PCOS compared
to controls (175.6 ± 96.3 and 257.2 ± 64.3 mg.m−2.min−1) at baseline, yet both PEDF and BMI were similar between
groups. PEDF negatively correlated to GIR (r = −0.41, P = 0.03) and high-density lipoprotein (HDL) (r = −0.46,
P = 0.01), and positively to cardiovascular risk factors, systolic (r = 0.41, P = 0.02) and diastolic blood pressure
(r = 0.47, P = 0.01) and triglycerides (r = 0.49, P = 0.004). The correlation with GIR was not significant after adjusting
for fat mass (P = 0.07). Exercise training maintained BMI and increased GIR in both groups; however, plasma PEDF
was unchanged. In summary, PEDF is not elevated in PCOS, is not associated with IR when adjusted for fat mass,
and is not reduced by endurance exercise training despite improved insulin sensitivity. PEDF was associated with
cardiovascular risk factors, suggesting PEDF may be a marker of cardiovascular risk status.