Aim: To investigate the association between uric acid (UA) and endothelial function in Chinese hypertensive patients with Metabolic Syndrome (MS).Methods: 615 hypertensive patients were enrolled, all hypertensives were divided into two groups: hypertensives with MS (MS group, n=239) and hypertensives without MS (NMS group, n=376). 87 age-and sex-matched normotensives served as controls (NC group). Flow-mediated (endothelium-dependent) dilatations (FMD), nitroglycerin-induced (endothelium-independent) dilatation (EID) in the brachial artery were assessed by highresolution ultrasonography. UA was detected by urease indophenol. .58)%, p<0.001) among groups. After stratification of gender, lower FMD was only seen in male hypertensives with MS accompanied by hyperuricemia <60 years old ((9.98 ± 5.78)% vs (7.12 ± 4.49)%, p<0.05); Pearson correlation analysis showed that the FMD was negatively correlated with UA (r=-0.314, p<0.01); Finally, logistic regression analysis showed that a 50 µmol/L increase in UA levels carried a 41.1% higher risk for endothelial dysfunction in this cohort. Conclusions: A higher UA level is related to poorer endothelial function in hypertensives with MS. Increased UA can be used as an alternative indicator for monitoring endothelial function and preventing vascular damage in male hypertensives with MS aged less than 60 years old.Keywords: Uric acid; Endothelial dysfunction; Hypertension; Metabolic syndrome
InstructionRecently, several studies have indicated that uric acid (UA), the circulating end-metabolite of purine nucleotides of mankind, is associated with subsequent cardiovascular diseases [1,2]. However, it remains controversial whether UA is a relevant and independent risk factor for cardiovascular disease and the mechanisms by which UA results in target organ injury are still unknown. Increasing data suggest that UA is associated with endothelial dysfunction [3,4], which is characteristic of patients with essential hypertension [5]. It is well recognized that endothelial dysfunction is an early stage in atherogenesis and associates with poor cerebro-cardiovascular outcomes [6]. It has been shown that UA disturbs endothelial function by disrupting nitric oxide (NO) synthesis, inhibiting NO bioavailability and activating the renin-angiotensin system.Metabolic syndrome (MS) is believed to be a clustering of abnormalities of several cardiovascular risk factors in an individual including abdominal obesity, hypertension, and dyslipidemia, including low HDL-C, high LDL-C and hyperglycemia. MS is often associated with elevated UA levels [7] and endothelial dysfunction [8,9]. The prevalence of MS has been increasing in recent years in China. A recent epidemiological study showed that the prevalence of MS among Chinese men and women aged 35 to 64 years old was 9.8% and 17.8%, respectively [10]. As is known to all, MS is quite common in patients with primary hypertension and carries much higher risk of cardiovascular events. It was reported that nearly 90% of Chinese hypertensives were ...