夜间脉压下降率与老年人靶器官损害的关系

The relationship between blunted reduction of nighttime pulse pressure and target organ damage in elderly hypertensive patients

目的在了解夜间脉压下降率的基础上,探讨夜间脉压下降率与靶器官损害的关系。方法回顾性研究325例曾在我院行动态血压检查的住院患者,了解夜间脉压下降率的规律。另外选择来我院就诊首次发现高血压病的老年患者124例,根据脉压夜间下降率中位数水平分为两组:脉压夜间下降率<6.5%组(A组)和脉压夜间下降率≥6.5%组(B组),同时测量24小时动态血压,心律失常发生率,左心室质量指数(LVMI),内皮功能指标及一般临床生化指标。结果夜间脉压下降率为8±9%,中位数为6.5%。脉压夜间下降率<6.5%组(A组)和脉压夜间下降率≥6.5%组(B组)比较,夜间脉压组(A组61±8mmHg,B组54±9mmHg,P<0.05),平均脉压(A组61±7mmHg,B组58±8mmHg,P<0.05),非勺形高血压比例(A组66%,B组42%,P=0.045)。脉压夜间下降率<6.5%组(A组)靶器官损害较严重。LVMI(A组134±28g/m2,B组117±32g/m2,P<0.001)、心律失常(A组27.7%,B组7.7%,P<0.025)、尿微蛋白(A组21.8%,B组8.2%,P<0.05)、脑血管损害(25.4%,10.7%,P<0.05)差异有统计学意义。LVMI与夜间脉压下降率做直线相关分析,呈负相关(r=-0.403,P<0.001)。脉压夜间下降率<6.5%组(A组)吸烟率较高(A组44%,B组21%,P<0.005),内皮功能损伤较严重:Flow-MD/%(A组4.5±0.32,B组10.4±0.47,P<0.0005)、vWF(A组174.3±22.3,B组152.4±21.1,P<0.0005)差异有统计学意义(P<0.0005)。结论脉压在夜间下降,脉压存在昼夜变化。夜间脉压下降率<6.5%(A组)较夜间脉压下降率≥6.5%(B组)靶器官损害程度重。脉压昼夜变化与内皮功能有着密切的关系。

Objective To study the circadian variation of PP and evaluate the relationship between blunted reduction of pulse pressure during nighttime and target organ damage in elderly hypertensive patients. Methods in order to understand the circadian variation of pulse pressure, 325 hypertensive patients were studied. Ambulatory BP monitoring （every 30 rain for 24h） was performed in another 124 patients with untreated essential hypertension. The patients were divided into A group （reduction of pulse pressure during nighttime〈6.5%） and B group （reduction of pulse pressure during nighttime ≥ 6.5%）. LVMI, urine microalhum in excretion, incidence of arrhythmia and brain damage were measured, Endothelial function was assessed in the brachial artery by high resolution ultrasound technique, and vWF was measured using ELISA. Results PP was decreased during nighttime（8±9%） reduction from daytime PP, median value was 6.5%）. Compaired with those in group B, the pulse pressure and the proportion of nondipper hypertension were higher in those in group A. The incidence of target organ damage was significantly different between group A and group B. The percent of nighttime PP from daytime PP had a significant and inverse relation to LVMI （r=-0.403, P〈0.001）. vWF in group A was higher while endothelial function was lower. Conclusions PP is reduced during nighttime. The blunted reduction of nighttime PP may be an predictor of hypertension induced cardiovascular complications. The blunted reduction of nighttime PP may be closely related to endothelial function.