Covic Adrian, Mardare Nicoleta, Gusbeth-Tatomir Paul, Prisada Octavian, Sascau Radu, Goldsmith David J A
Dialysis and Transplantation Center, C. I. PARHON University Hospital, 50 Carol 1st Blvd., Iasi, 700503 Romania.
Nephrol Dial Transplant. 2006 Oct;21(10):2859-66. doi: 10.1093/ndt/gfl307. Epub 2006 Jul 19.
Chronic kidney disease (CKD) patients have a 3-30-fold increased risk of death compared with the general population. This mortality difference is even more pronounced in younger subjects. Two markers of aortic stiffness--aortic pulse wave velocity (PWV) and augmentation index (AIx)--have been prospectively related to all-cause and cardiovascular (CV) mortality in end-stage renal disease (ESRD) populations. The aims of our study were first, to confirm the important deleterious effect of arterial stiffness in uraemia and second, to assess the impact on survival of increased AIx in a relatively young non-diabetic dialysis population, with minimal CV disease.
Ninety-two patients (mean age 42.6 +/- 11.2 years) were included in the study and followed for a period of 61 +/- 25 months. None of the patients had diabetes mellitus, and only 3.3% had prior history of CV disease. AIx was determined by applantation tonometry using a SphygmoCor device (AtCor, PWV Inc., Westmead, Sydney, Australia).
Mean AIx in our study population was 19.9 +/- 13.7%; other significant haemodynamic parameters were: systolic blood pressure (SBP) 129 +/- 24 mmHg, pulse pressure 35.3 +/- 17.5 mmHg with 27.2% of the study population receiving angiotensin-converting enzyme inhibitors (ACE-I). On univariate analysis, in our group AIx correlated with: body weight (P < 0.001), radial SBP (P < 0.001) and haemoglobin levels (P < 0.05). There was no correlation between AIx and any of the echocardiographic parameters. In the stepwise multiple regression analysis, the only independent predictors for AIx were weight (P < 0.001), SBP (P < 0.001) and haemoglobin (P < 0.05) with the model explaining 33% of the AIx variability (adjusted R(2) = 0.33). During the follow-up period, 15 deaths were recorded. In the Cox analysis (P = 0.014; chi square 20.7 for the model) the only independent predictors for all-cause mortality were age (P = 0.001), left ventricular mass index (P = 0.032) and ACE-I therapy (P = 0.039) while AIx did not reach statistical significance. There was no difference in patients' survival when divided by AIx tertiles, assessed by the log rank test (P = 0.78).
Our results fail to support the notion that an increased effect of wave reflections on central arteries is a strong and independent predictor of mortality in all ESRD patients on haemodialysis. The effect of arterial wave reflections might be in fact dependent on patient age and concurrent comorbidity status.
与普通人群相比，慢性肾脏病（CKD）患者的死亡风险增加了3至30倍。这种死亡率差异在年轻受试者中更为明显。主动脉僵硬度的两个指标——主动脉脉搏波速度（PWV）和增强指数（AIx）——已被前瞻性地证明与终末期肾病（ESRD）人群的全因死亡率和心血管（CV）死亡率相关。我们研究的目的首先是确认动脉僵硬度在尿毒症中的重要有害作用，其次是评估在相对年轻、无糖尿病且心血管疾病极少的透析人群中，AIx升高对生存的影响。
92例患者（平均年龄42.6±11.2岁）纳入本研究，并随访61±25个月。所有患者均无糖尿病，仅有3.3%有心血管疾病史。使用SphygmoCor设备（AtCor，PWV Inc.，澳大利亚悉尼韦斯特米德）通过应用张力测量法测定AIx。
我们研究人群的平均AIx为19.9±13.7%；其他重要的血流动力学参数为：收缩压（SBP）129±24 mmHg，脉压35.3±17.5 mmHg，27.2%的研究人群接受血管紧张素转换酶抑制剂（ACE-I）治疗。单因素分析显示，在我们的研究组中，AIx与体重（P<0.001）、桡动脉SBP（P<0.001）和血红蛋白水平（P<0.05）相关。AIx与任何超声心动图参数均无相关性。在逐步多元回归分析中，AIx的唯一独立预测因素是体重（P<0.001）、SBP（P<0.001）和血红蛋白（P<0.05），该模型解释了AIx变异性的33%（调整后R² = 0.33）。随访期间，记录到15例死亡。在Cox分析中（P = 0.014；模型的卡方值为20.7），全因死亡率的唯一独立预测因素是年龄（P = 0.001）、左心室质量指数（P = 0.032）和ACE-I治疗（P = 0.039），而AIx未达到统计学显著性。根据AIx三分位数进行分组，通过对数秩检验评估患者生存率差异无统计学意义（P = 0.78）。
我们的结果不支持以下观点，即波反射对中心动脉的增强作用是所有接受血液透析的ESRD患者死亡率的强大且独立的预测因素。动脉波反射的影响实际上可能取决于患者年龄和并发疾病状态。
