Autonomic dysfunction and flow-mediated dilation in polycystic ovary syndrome (PCOS): A case-control study. Dysautonomia in polycistic ovary syndrome

Aim: a case-control study was conducted on women with polycystic ovary syndrome (PCOS) with a view to identifying endothelial and autonomic nervous system dysfunctions capable of explaining the higher cardiovascular risk associated with PCOS. Material and methods: 35 women (mean age 26.51 ±3; BMI 24.25 ±1.65) with documented PCOS and 35 controls matched for age, BMI and cardiovascular risk factors were studied during a solar year. Endothelial dysfunction was assessed using flow-mediated dilation (FMD) and early atherosclerosis from the intima media thickness (IMT) of the carotid district measured using eco-color Doppler. Autonomic dysfunction was assessed with the classic tests (tilt, lying-to-standing, deep breath, Valsalva, Stroop). Results: by comparison with controls, patients with PCOS had an altered response in some of the autonomic tests, i.e. lying-to-standing (mean values 3.25 ±4 mmHg vs -3.4 ±2.04, p<0.01); deep breath (RR max/RR min 1.03 ±0.04 vs 1.35 ± 0.05, p<0.01) and Valsalva (RRmax/RRmin 1.10 ± 0.05 vs 1.35 ± 0.05, p<0.01), but no relevant differences in the tilt, hand grip and Stroop tests. A diminished FMD (0.56 ± 0.8mm vs 0.74 ± 0.06mm, p<0.01) and a greater IMT (0.72 ± 0.03 vs 0.67 ± 0.03mm, p=0.031) were found in cases than in controls. Conclusions: PCOS coincides with an endothelial dysfunction and a greater IMT, and autonomic assessment reveals sympathetic hyperactivity. These two findings may explain the link between PCOS and cardiovascular disease. Further studies are needed to shed light on this apparent link and demonstrate whether it is real and quantifiable.