Endocrine Abstracts

Introduction: Polycystic ovary syndrome (PCOS) is a common, multi-system condition often associated with hyperandrogenism. Patients demonstrate increased risk of cardio- and cerebrovascular abnormalities. The exact mechanism for this is unknown but may involve a direct action of testosterone on the cerebrovascular system. The current study investigates multiple cerebrovascular functions in PCOS patients compared to healthy controls and specifically investigates associations with testosterone.

Methods: 15 PCOS patients (testosterone mean[SD]=1.39[0.47]nmol/l) and 13 BMI-and-age-matched healthy controls (testosterone mean[SD]=1.13[0.43]) completed an MRI session (Siemens MAGNETOM Prisma 3T scanner). A multi-post labelling delay pseudocontinuous arterial spin labelling (MPLD-pCASL) perfusion scan (maximum TR=5.6s; TE=11s; voxel resolution=3.4x3.4x6.0mm; tag duration=1800; post-labelling delays=250-3000ms in steps of 250ms) assessed regional Cerebral Blood Flow (CBF). A T2-relaxation-under-spin-tagging (TRUST) sequence (TR=3s; TE=3.9ms) estimated global oxygen extraction fraction and cerebral metabolic rate of oxygen. Linear models investigated the amount of vascular function that could be explained by PCOS status or additional testosterone variance.

Results: A significant CBF association was found with PCOS status (χ² (1)=52.715; P = 3.856x10^-13) and testosterone (χ² (1)= 63.987; P = 1.253x10^-15). While PCOS status reduced CBF by -6.561ml/100g/min±0.864 (standard error [SE]), additional testosterone variance was associated with an increase of 1.981ml /100g/min±0.238 (SE) with each 0.1nmol/l increase. Further investigation suggested that both effects occurred globally. Neither had a significant association with any other outcome function.

Conclusion: These results illustrate how PCOS status and testosterone level influence the cerebrovascular system, which occurred globally across cortical and subcortical regions. Any CBF shift would impact oxygen delivery. The opposing directions found in CBF may suggest that factors outside of hyperandrogenism lead to the PCOS status difference, and increased testosterone may actually be protective, at least in this young cohort.