Curgunlu A, Uzun H, Bavunoğlu I, Karter Y, Genç H, Vehid S
Department of Internal Medicine, Cerrahpaşa Medical Faculty, Istanbul University, Istanbul, Turkey.
J Hum Hypertens. 2005 Aug;19(8):629-33. doi: 10.1038/sj.jhh.1001867.
Elevated plasma levels of the endogenous nitric oxide (NO) synthase inhibitor asymmetric dimethylarginine (ADMA) contribute to endothelial dysfunction and seem to be a predictor for cardiovascular mortality. Elevated ADMA plasma concentrations have been demonstrated in patients with hypertension. However, the plasma concentrations of ADMA in white coat hypertension (WCH) has not been previously studied. The aim of this study was to evaluate ADMA in WCH and compare with normotensive (NT) and hypertensive (HT) patients. We also evaluated the relation between ADMA and NO in these three groups. For this purpose, 34 NT, 34 white coat hypertensive (clinical hypertension and ambulatory daytime blood pressure <135/85 mmHg) and 34 HT patients were recruited in this study. The subjects were matched for age, gender, body mass index (BMI) and the patients with smoking habit, dyslipidaemia and diabetes mellitus were excluded. The ADMA levels were determined by high performance liquid chromatography. Plasma ADMA levels were significantly higher in WCH group than in the NT group (3.21+/-0.49 micromol/l vs 2.84+/-0.58 micromol/l, P=0.046). It was significantly higher in the HT group than in the NTs (4.24+/-0.38 micromol/l, P<0.001). There was also a significant difference between the HT and WCH groups (P<0.001). The WCH subjects had significantly higher levels of NO than the HTs (41.68+/-2.23 vs 32.18+/-2.68 micromol/l; P<0.001) and significantly lower values than the NTs (48.24+/-4.29 micromol/l; P<0.001). In WCH and HT group, there was a negative correlation between ADMA and NO (r=-0.515, P=0.003 and r=-0.389, P=0.034, respectively). In NT subjects, there was no correlation between these two parameters (r=-0.287, P=0.124). The correlation between ADMA and NO was stronger in WCH group than in HT group. Although NO levels in HT patients were lower than WCHs and ADMA levels were higher in HT patients than WCHs, the negative correlation of these two parameters were more pronounced in WCH group. Decreased NO and increased ADMA levels in WCH may indicate endothelial dysfunction. Our data indicate also that WCH represent an intermediate group between NT and HT when endothelial dysfunction is concerned.
内源性一氧化氮（NO）合酶抑制剂非对称二甲基精氨酸（ADMA）的血浆水平升高会导致内皮功能障碍，并且似乎是心血管死亡率的一个预测指标。高血压患者中已证实ADMA血浆浓度升高。然而，此前尚未研究过白大衣高血压（WCH）患者的ADMA血浆浓度。本研究的目的是评估WCH患者的ADMA水平，并与血压正常（NT）和高血压（HT）患者进行比较。我们还评估了这三组中ADMA与NO之间的关系。为此，本研究招募了34名NT患者、34名白大衣高血压患者（临床高血压且动态日间血压<135/85 mmHg）和34名HT患者。受试者在年龄、性别、体重指数（BMI）方面相匹配，排除有吸烟习惯、血脂异常和糖尿病的患者。ADMA水平通过高效液相色谱法测定。WCH组的血浆ADMA水平显著高于NT组（3.21±0.49 μmol/l对2.84±0.58 μmol/l，P = 0.046）。HT组显著高于NT组（4.24±0.38 μmol/l，P<0.001）。HT组和WCH组之间也存在显著差异（P<0.001）。WCH受试者的NO水平显著高于HT患者（41.68±2.23对32.18±2.68 μmol/l；P<0.001），且显著低于NT患者（48.24±4.29 μmol/l；P<0.001）。在WCH组和HT组中，ADMA与NO之间存在负相关（分别为r = -0.515，P = 0.003和r = -0.389，P = 0.034）。在NT受试者中，这两个参数之间无相关性（r = -0.287，P = 0.124）。WCH组中ADMA与NO之间的相关性比HT组更强。尽管HT患者的NO水平低于WCH患者，且ADMA水平高于WCH患者，但这两个参数的负相关性在WCH组中更明显。WCH患者中NO降低和ADMA水平升高可能表明内皮功能障碍。我们的数据还表明，就内皮功能障碍而言，WCH代表了NT和HT之间的中间组。
