Brunelli Steven M, Thadhani Ravi I, Lynch Katherine E, Ankers Elizabeth D, Joffe Marshall M, Boston Raymond, Chang Yuchaio, Feldman Harold I
Renal, Electrolyte, and Hypertension Division, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
Am J Kidney Dis. 2008 Oct;52(4):716-26. doi: 10.1053/j.ajkd.2008.04.032. Epub 2008 Aug 27.
Blood pressure variability (BPV) is one putative risk factor for cardiovascular disease and mortality in hemodialysis patients. The purposes of this study are to identify a suitable metric of long-term BPV in this population and determine whether an association between BPV and all-cause mortality exists.
Retrospective cohort study.
SETTINGS & PARTICIPANTS: Patients from the Accelerated Mortality on Renal Replacement (ArMORR) cohort who were adult, incident to hemodialysis at any Fresenius Medical Care unit between June 2004 and August 2005, and had suitable blood pressure data were studied (n = 6,961).
Predialysis blood pressures measured between dialysis days 91 and 180 were used to determine each patient's absolute level of, trend in (slope over time), and variability in blood pressure.
All-cause mortality beginning immediately after day 180 and continuing through day 365 or until censoring (median follow-up, 185 days).
Of the 4 candidate BPV metrics, only average residual-intercept ratio adequately distinguished BPV from absolute blood pressure level and temporal blood pressure trend. In the primary analysis, each SD increase in systolic and diastolic BPV was associated with adjusted hazard ratios for all-cause mortality of 1.13 (95% confidence interval, 1.03 to 1.23) and 1.15 (95% confidence interval, 1.06 to 1.26), respectively. Results were consistent across multiple sensitivity analyses in which inclusion and exclusion criteria and timing of blood pressure measurements were varied.
Contingency of results on the validity of mathematic description of BPV; potential for misclassification bias and residual confounding.
Provided the mathematical descriptions of BPV are valid, the data suggest that systolic and diastolic BPV is associated with all-cause mortality in incident hemodialysis patients. Additional study is necessary to confirm and generalize findings, assess the interplay between systolic and diastolic BPV, and assess causality.
血压变异性（BPV）是血液透析患者心血管疾病和死亡的一个假定危险因素。本研究的目的是确定该人群中长期BPV的合适指标，并确定BPV与全因死亡率之间是否存在关联。
回顾性队列研究。
来自肾脏替代加速死亡（ArMORR）队列的患者，这些患者为成年人，于2004年6月至2005年8月期间在任何费森尤斯医疗护理单位开始进行血液透析，且有合适的血压数据（n = 6,961）。
透析第91天至180天之间测量的透析前血压用于确定每位患者的血压绝对水平、血压趋势（随时间的斜率）和血压变异性。
全因死亡率从第180天之后立即开始，持续至第365天或直至截尾（中位随访时间为185天）。
在4种候选BPV指标中，只有平均残差-截距比能充分区分BPV与绝对血压水平及血压时间趋势。在初步分析中，收缩压和舒张压BPV每增加1个标准差，全因死亡率的校正风险比分别为1.13（95%置信区间为1.03至1.23）和1.15（95%置信区间为1.06至1.26）。在多种敏感性分析中，包括纳入和排除标准以及血压测量时间不同的情况下，结果均一致。
结果取决于BPV数学描述的有效性；存在错误分类偏倚和残余混杂的可能性。
如果BPV的数学描述有效，则数据表明收缩压和舒张压BPV与新进入血液透析的患者的全因死亡率有关。需要进一步研究以证实并推广这些发现，评估收缩压和舒张压BPV之间的相互作用，并评估因果关系。
