Endothelial Dysfunction in Young Women with Polycystic Ovary Syndrome: Relationship with Insulin Resistance and Low-Grade Chronic Inflammation

Abstract

Women with polycystic ovary syndrome (PCOS) carry a number of cardiovascular risk factors. Cardiovascular morbidity is elevated even in young women with PCOS. Low-grade chronic inflammation, reflected in elevated levels of serum C-reactive protein (CRP) and endothelial dysfunction have recently been linked to development of atherosclerosis. We compared high-sensitivity (hs)CRP concentrations and endothelium dysfunction in 37 women with PCOS and 25 control subjects matched as a group for age and body mass index (BMI). Arterial endothelium and smooth muscle function was measured by examining brachial artery responses to endothelium-dependent and endothelium-independent stimuli. Serum LH, testosterone, androstenedione, and fasting insulin levels were significantly higher in the PCOS group than the control group. The PCOS group was more insulin resistant than age- and BMI-matched control women. CRP concentrations were higher in PCOS women than the healthy control group (0.25 vs. 0.09 mg/dl). hsCRP concentrations were correlated with BMI, insulin sensitivity indices (homeostasis model assessment and quantitative insulin sensitivity check index), and endothelium-dependent vasodilation. The groups were well matched for baseline brachial artery diameter. There was a significant difference in endothelium-dependent (flow- mediated dilation) and endothelium-independent (sublingual nitroglycerin) vascular responses between the women with PCOS and the normal healthy control group (P = 0.002 and P = 0.01, respectively). Endothelium-dependent vasodilation was correlated with hsCRP concentrations and insulin resistance. In conclusion, this study is the first to demonstrate increased levels of hsCRP, endothelial dysfunction, and the relation with insulin resistance in young and normal-weight women with PCOS. Clinical strategies aimed at reducing insulin resistance may prevent early atherosclerosis in women with PCOS.