Resting Cerebrovascular Haemodynamics and Dynamic Assessment of Cerebrovascular Function in Polycystic Ovary Syndrome

Objective: Despite an increased cerebrovascular disease risk, the impact of Polycystic Ovary Syndrome (PCOS) on cerebrovascular haemodynamics and function is unknown. This study characterised cerebrovascular haemodynamics and function in women with PCOS versus healthy controls. Design: Case‐control study. Patients: Fifteen women with PCOS (age: 31 ± 6 years; body mass index (BMI): 31.8 ± 5.7 kg/m2) and 16 controls (age: 30 ± 7 years; BMI: 29.9 ± 5.5 kg/m2). Measurements: Resting global cerebral blood (CBF) was assessed by 3T MRI. Middle‐ and posterior cerebral artery blood velocities (MCAv, PCAv) were measured by Doppler ultrasound and pulsatility index (MCAPI, PCAPI) calculated. Neurovascular coupling (NVC), internal carotid artery cerebrovascular reactivity (CVRCO2) and dynamic cerebral autoregulation (dCA) directional sensitivity were assessed using a visual stimulus, 6% fixed‐inspired CO2 and repeated squat‐stand manoeuvres, respectively. Results: Resting CBF (PCOS: 57.2 ± 7.5 ml/100 g/min; controls: 61.6 ± 11.6 ml/100 g/min, p = 0.25) and MCAv, PCAv, MCAPI and PCAPI (all p > 0.05) were similar between groups. NVC (14 ± 4.9% vs. 13 ± 3.4%, p = 0.45), CVRCO2 (5.1 ± 1.9% vs. 6.5 ± 2.9%, p = 0.20) and dCA directional sensitivity were similar between groups. However, women with PCOS had elevated relative PCAPI during NVC (PCOS: 12.0 ± 5.6% vs. controls: 7.0 ± 3.8%, p = 0.04), and impaired vasodilation of the internal carotid artery during CVRCO2 (PCOS: −0.10 ± 0.22 mm vs. controls: 0.18 ± 0.24 mm, p < 0.01). Conclusions: Cerebrovascular function is largely preserved in women with PCOS, although elevated arterial pulsatility and impaired vasodilatory response to carbon dioxide may indicate early endothelial dysfunction in the cerebral vasculature. Larger studies are needed to confirm this in view of our limited study power.