Kantaria N, Pantsulaia I, Andronikashvili I, Simonia G
Department of Internal Medicine, Tbilisi State Medical University, Tbilisi, Georgia.
Georgian Med News. 2016 Sep(258):33-37.
This investigation differentiates types of essential hypertension in a Georgian population as well as describes endogenous cardiotonic steroids in salt-sensitive and salt-resistant subjects. This case control study included 185 subjects: 94 cases with stage 1 essential hypertension (JNC7) naïve to antihypertensive treatment, and 91 controls. A salt-sensitivity test was used to dichotomize case and control groups into salt-sensitive and salt-resistant subgroups. Blood and urine samples were obtained to categorize participants as consuming high and low salt diets. Endogenous cardiotonic steroids, sodium and plasma-renin activity (PRA) were measured in both samples at the different sodium conditions. Determinants of circulating levels of endogenous sodium pump inhibitors were carried out using the ELISA and RIA methods; PRA was assessed by radioimmunoassay. Descriptive statistics were used to analyze the data. Differences in variables between sodium conditions were assessed using paired t-tests. Salt-sensitivity was found in 60.5% of the total population investigated, with a higher proportion in females. A statistically significant positive correlation was found between salt-sensitivity and age in females (r=0.262, p<0.01), and with 24-hour urine sodium concentration changes (r=0.334, p<0.01). A significant negative correlation was found between salt-sensitivity and PRA. At the high sodium condition, endogenous MBG and OU were high in salt-sensitive subjects compared to those who were salt-resistant. These compounds decreased with a low-salt diet in both salt-sensitive cases and controls but remained the same in salt-resistant individuals. The MBG and OU levels positively correlated with systolic blood pressure in salt-sensitive individuals but no variability was evident among salt-resistant subjects. Our results show that MBG and OU levels start to increase at the normotensive stage and sustained high concentrations can lead to elevated systolic blood pressure, a risk factor for arterial hypertension in salt-sensitive subjects.
这项研究对格鲁吉亚人群中的原发性高血压类型进行了区分，并描述了盐敏感和盐抵抗受试者体内的内源性强心甾体。这项病例对照研究纳入了185名受试者：94例未经抗高血压治疗的1级原发性高血压（JNC7）患者，以及91名对照者。采用盐敏感性试验将病例组和对照组分为盐敏感和盐抵抗亚组。采集血液和尿液样本，以将参与者分类为高盐饮食和低盐饮食者。在不同钠条件下，对两份样本中的内源性强心甾体、钠和血浆肾素活性（PRA）进行了测量。使用酶联免疫吸附测定法（ELISA）和放射免疫测定法（RIA）测定内源性钠泵抑制剂循环水平的决定因素；通过放射免疫测定法评估PRA。使用描述性统计分析数据。采用配对t检验评估钠条件之间变量的差异。在所研究的总人口中，60.5%发现有盐敏感性，女性比例更高。在女性中，盐敏感性与年龄之间存在统计学显著的正相关（r = 0.262，p < 0.01），与24小时尿钠浓度变化之间也存在正相关（r = 0.334，p < 0.01）。盐敏感性与PRA之间存在显著负相关。在高钠条件下，与盐抵抗者相比，盐敏感受试者体内的内源性髓质素（MBG）和哇巴因（OU）含量较高。在盐敏感病例和对照者中，这些化合物在低盐饮食时均降低，但在盐抵抗个体中保持不变。在盐敏感个体中，MBG和OU水平与收缩压呈正相关，但在盐抵抗受试者中未观察到明显变化。我们的结果表明，在血压正常阶段，MBG和OU水平开始升高，持续的高浓度可导致收缩压升高，这是盐敏感受试者动脉高血压的一个危险因素。
