Statin ameliorates endothelial dysfunction and insulin resistance in Tibet women with polycystic ovary syndrome

OBJECTIVE: Polycystic ovary syndrome (PCOS) is a disorder characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovaries. In Tibet population, little is known about the correlation between PCOS and endothelial function and insulin resistance. In this study, we investigated the efficacy of simvastatin on ameliorating endothelial dysfunction and insulin resistance in Tibet patients with PCOS. PATIENTS AND METHODS: A group of 21 PCOS women was compared with 21 age-paired controls for blood pressure, body mass index (BMI), lipids, glucose and insulin levels. Plasma ET-1 was quantitated using a commercially available ELISA kits. The invasive vascular endothelial function was evaluated through the measurement of brachial artery flow-mediated dilation (FMD) in the fasting state using high-resolut ion B-mode ultrasound and ankle-brachial index (ABI) by using a blood pressure cuff and a Doppler instrument. RESULTS: PCOS women had higher BMI (p < 0.05), blood pressure (p < 0.05), cholesterol (p < 0.05), triglyceride (p < 0.05), LDL cholesterol (p < 0.05) and lower HDL cholesterol (p < 0.05). Fasting insulin (p < 0.001) and 2-hour plasma glucose (p < 0.001) of PCOS were also found to be higher than that of controls. HOMA-IR of PCOS was calculated to be much higher than that of the control group (p < 0.001). ET-1 levels were significantly higher in the PCOS women compared with the control group (p < 0.001). FMD and ABI were impaired in the PCOS group when compared with the controls (p < 0.001). After simvastatin intervention for 6 months, FMD, ABI, HOMA-IR, lipid profile, BMI were ameliorated in PCOS women. Also, FMD, ABI, HOMA-IR, lipid profile were nearly normalized in PCOS women after statin treatment compared with the control women. Tibet PCOS patients present a clustering of atherosclerosis risk factors (obesity, adverse lipid profile, hypertension and hyperglycemia) and more prevalent in insulin resistance and endothelial dysfunction than non-PCOS women. CONCLUSIONS: The endothelial function and insulin resistance of PCOS patients were ameliorated after statin administration.