Agarwal Rajiv, Light Robert P
Indiana University School of Medicine, Indianapolis, Indiana, USA.
Clin J Am Soc Nephrol. 2008 Nov;3(6):1660-8. doi: 10.2215/CJN.02920608. Epub 2008 Oct 15.
Patients with chronic kidney disease (CKD) have an elevated cardiovascular risk. This study was designed to understand better the presence and strength of the relationship between physical activity and BP and to explore determinants of hemodynamic reactivity.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Twenty-four patients with CKD (mean age 69.5 yr; 3.1 antihypertensive drugs; estimated GFR 47 ml/min per 1.73 m(2), albumin/creatinine ratio 403 mg/g) were studied on three occasions during a 6-wk period with 24-h ambulatory BP monitoring and simultaneous activity monitoring with wrist actigraphy.
Nondippers were found have a greater level of sleep activity compared with dippers, although the awake activity level was similar (7.06 versus 6.73) between groups (P = 0.042 for interaction). In 3587 BP activity pairs, hemodynamic reactivity was variable between individuals (systolic BP reactivity 1.06 [SD 10.50]; diastolic BP reactivity 0.89 [SD 7.80] heart rate reactivity 1.18 [SD 11.00]); those who were more sedentary had a greater increment in systolic BP compared with those who were less sedentary. Antihypertensive drugs blunted hemodynamic reactivity. Hemodynamic reactivity was greatest between 12 a.m. and 8 a.m., making this a vulnerable period for cardiovascular events.
Greater hemodynamic reactivity in sedentary people with CKD offers a possible and thus far unrecognized mechanism of cardiovascular damage. Besides reducing BP, antihypertensive drugs reduce hemodynamic reactivity, which offers another plausible mechanism of cardiovascular protection with their use.
慢性肾脏病（CKD）患者心血管风险升高。本研究旨在更好地了解身体活动与血压之间关系的存在情况及强度，并探索血流动力学反应性的决定因素。
设计、地点、参与者及测量方法：24例CKD患者（平均年龄69.5岁；服用3.1种抗高血压药物；估计肾小球滤过率为47 ml/min/1.73 m²，白蛋白/肌酐比值为403 mg/g）在6周期间分三次接受研究，采用24小时动态血压监测，并同时使用手腕活动记录仪进行活动监测。
与杓型血压者相比，非杓型血压者的睡眠活动水平更高，尽管两组之间的清醒活动水平相似（分别为7.06和6.73）（交互作用P = 0.042）。在3587对血压与活动数据中，个体间的血流动力学反应性存在差异（收缩压反应性1.06 [标准差10.50]；舒张压反应性0.89 [标准差7.80]；心率反应性1.18 [标准差11.00]）；久坐者与较少久坐者相比，收缩压升高幅度更大。抗高血压药物会减弱血流动力学反应性。血流动力学反应性在凌晨12点至上午8点之间最强，这使得此时间段成为心血管事件的易发生期。
CKD久坐者中较高的血流动力学反应性提供了一种迄今未被认识的心血管损伤机制。除了降低血压外，抗高血压药物还能降低血流动力学反应性，这为其使用提供了另一种合理的心血管保护机制。
