Endothelial dysfunction in PCOS: role of obesity and adipose hormones

Polycystic ovary syndrome (PCOS) is an extremely prevalent disorder in which elevated blood markers of cardiovascular risk and altered endothelial function have been found. This study was designed to determine if abnormal carotid intima-media thickness (IMT) and brachial flow-mediated dilation (FMD) in young women with PCOS may be explained by insulin resistance and elevated adipocytokines.

A prospective study in 50 young women with PCOS (age: 25.2 +/- 1 years; body mass index [BMI]: 28.7 +/- 0.8) and 50 matched ovulatory controls (age: 25.1 +/- 0.7 years; BMI: 28.5 +/- 0.5) was performed. Carotid IMT, brachial FMD, and blood for fasting glucose, insulin, leptin, adiponectin and resistin were measured.

PCOS, IMT was increased (P <.01), FMD was decreased (P <.01), fasting insulin was increased (P <.01), QUICKI (a marker of insulin resistance) was decreased (P <.01), and adiponectin was lower (P <.05), whereas leptin and resistin were not different compared with matched controls. Whereas BMI or waist/hip ratios did not correlate with IMT or FMD, insulin and QUICKI correlated positively and negatively with IMT (P <.01). There was a significant negative correlation between adiponectin and IMT (P <.05). These correlations were unchanged when adjusting for BMI and the correlation between IMT and adiponectin was unaffected by insulin resistance parameters.

These data suggest that young women with PCOS have evidence for altered endothelial function. Adverse endothelial parameters were correlated with insulin resistance and lower adiponectin. Both insulin resistance and adiponectin appear to be important parameters. It is hypothesized that the type of fat distribution may influence these factors.