Evidence of an Increase in Baseline Brachial Artery Lumen Diameter Independent of Body Mass Index (BMI) among Women with Polycystic Ovary Syndrome (PCOS)Compared to Age-Matched Control Women
PCOS is a reproductive endocrine disorder, characterized by chronic anovulation, androgen excess, and insulin resistance, affecting approximately 5% of the female population. PCOS is associated with an increase in CHD risk factors, including LDL cholesterol,triglycerides, obesity,and hypertension. Endothelial dysfunction has been implicated in the development and progression of atherosclerosis and has been shown to be adversely affected in males with high free testosterone levels and in men and women with increased insulin resistance. We recruited 83 women with PCOS (42.3 ± 5.8 years) from our Pittsburgh cohort and 91 controls of similar age (43.4 ± 5.4 years) to evaluate endothelium-dependent vascular function using brachial artery ultrasonography. Women on hormone replacement or oral contraceptives were excluded from the analysis. The mean BMI ± SD was 31.7 ± 8.7 and 27.1 ± 6.4 kg/m 2 in cases and controls, respectively. The groups were also similar with respect to smoking status. No difference was observed in BMI-adjusted flow mediated vasodilation (FMD) between PCOS cases and controls (p=.630). However, baseline brachial lumen diameter (LD) was significantly higher among women with PCOS compared to controls (Mean ± SE = 3.30 ± .06 vs. 3.12 ± .05) after adjustment(p=.023). Further adjustment for LDLc, HDLc, triglycerides, systolic blood pressure (SBP), or insulin did not alter the PCOS-brachial lumen diameter association. Independently of case status and BMI, HDLc was significantly associated with baseline LD(p=.001); DBP was of borderline significance(p=.099). These findings suggested that PCOS may be associated with a compensatory enlargement of the arteries in response to accelerated arterial wall thickening and/or arterial stiffening. Further analyses within PCOS cases suggested that testosterone and insulin may mediate endothelial function (FMD). Future studies are needed to futher explore vascular changes and the implication for cardio- and cerebrovascular events in this high risk population.