Samimi Arian, Ramesh Sharanya, Turin Tanvir C, MacRae Jennifer M, Sarna Magdalena A, Reimer Raylene A, Hemmelgarn Brenda R, Sola Darlene Y, Ahmed Sofia B
Faculty of Medicine, University of Alberta, Calgary, Alberta, Canada Libin Cardiovascular Institute of Alberta, CalgaryAlberta, Canada.
Libin Cardiovascular Institute of Alberta, CalgaryAlberta, Canada Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada.
Physiol Rep. 2014 Dec 11;2(12). doi: 10.14814/phy2.12235. Print 2014 Dec 1.
Uric acid is associated with hypertension and increased renin-angiotensin system activity, although this relationship diminishes after chronic exposure to high levels. Uric acid is more strongly associated with poor outcomes in women compared to men, although whether this is due to a sex-specific uric acid-mediated pathophysiology or reflects sex differences in baseline uric acid levels remains unknown. We examined the association between uric acid and vascular measures at baseline and in response to angiotensin-II challenge in young healthy humans. Fifty-two subjects (17 men, 35 premenopausal women) were studied in high-salt balance. Serum uric acid levels were significantly higher in men compared to women (328 ± 14 μmol/L vs. 248 ± 10 μmol/L, P < 0.001), although all values were within normal sex-specific range. Men demonstrated no association between uric acid and blood pressure, either at baseline or in response to angiotensin-II. In stark contrast, a significant association was observed between uric acid and blood pressure at baseline (systolic blood pressure, P = 0.005; diastolic blood pressure, P = 0.02) and in response to angiotensin-II (systolic blood pressure, P = 0.035; diastolic blood pressure, P = 0.056) in women. However, this sex difference lost significance after adjustment for baseline uric acid. When all subjects were stratified according to high (>300 μmol/L) or low (≤300 μmol/L) uric acid levels, only the low uric acid group showed a positive association between uric acid and measures of vascular tone at baseline and in response to angiotensin-II. Differences in uric acid-mediated outcomes between men and women likely reflect differences in exposure to increased uric acid levels, rather than a sex-specific uric acid-mediated pathophysiology.
尿酸与高血压及肾素 - 血管紧张素系统活性增加有关，尽管在长期暴露于高水平尿酸后这种关系会减弱。与男性相比，尿酸与女性不良结局的关联更强，不过这是由于性别特异性的尿酸介导的病理生理学，还是反映了基线尿酸水平的性别差异，目前尚不清楚。我们研究了年轻健康人群基线时以及对血管紧张素 - II刺激反应时尿酸与血管指标之间的关联。在高盐平衡状态下对52名受试者（17名男性，35名绝经前女性）进行了研究。男性的血清尿酸水平显著高于女性（328±14μmol/L对248±10μmol/L，P<0.001），尽管所有数值均在正常的性别特异性范围内。男性无论是在基线时还是对血管紧张素 - II的反应中，尿酸与血压之间均无关联。与之形成鲜明对比的是，女性在基线时（收缩压，P = 0.005；舒张压，P = 0.02）以及对血管紧张素 - II的反应中（收缩压，P = 0.035；舒张压，P = 0.056），尿酸与血压之间存在显著关联。然而，在对基线尿酸进行校正后，这种性别差异失去了显著性。当所有受试者按照尿酸水平高（>300μmol/L）或低（≤300μmol/L）进行分层时，只有低尿酸组在基线时以及对血管紧张素 - II的反应中，尿酸与血管张力指标之间呈现正相关。男性和女性在尿酸介导的结局方面的差异可能反映了暴露于升高的尿酸水平的差异，而非性别特异性的尿酸介导的病理生理学。
