Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
The Johns Hopkins University School of Medicine, The Johns Hopkins Bloomberg School of Public Health, and The Welch Center for Prevention, Epidemiology and Clinical Research, Baltimore, Maryland, USA.
Am J Hypertens. 2018 May 7;31(6):665-671. doi: 10.1093/ajh/hpy010.
Multiple definitions are used to characterize orthostatic hypotension (OH), but the degree to which these definitions correspond with orthostatic symptoms is unknown.
We analyzed data from African American Study of Kidney Disease and Hypertension (AASK), a randomized trial of African Americans with hypertension and kidney disease, to characterize the relationship between OH definitions and self-reported syncope, dizziness, or light-headedness. Orthostatic changes in systolic blood pressure (SBP), diastolic blood pressure (DBP), or heart rate (HR) were determined each visit after standing 2:45 minutes. OH was defined using the consensus definition (a drop in SBP ≥20 mm Hg or DBP ≥10 mm Hg) or an often used clinical substitute based on HR (an increase ≥20 bpm).
Among 1,094 participants (mean age 54.5 ± 10.7 years, 38.9% female), there were 52,636 visits (mean 48/person). Mean resting SBP, DBP, and HR at baseline were 147.7 ± 22.3 mm Hg, 92.2 ± 13.4 mm Hg, and 71.1 ± 11.7 bpm, respectively. While the OH consensus definition was associated with syncope (odds ratio 2.49; 95% confidence interval: 1.13, 5.51), dizziness (1.89; 1.53, 2.33), and light-headedness (1.84; 1.52, 2.23), the clinical HR definition was only associated with dizziness (1.28; 1.07, 1.52). None of the OH components (SBP, DBP, or HR) reflected a natural threshold in the prevalence of symptoms; definitions using each of the 3 components were highly specific (≥96%) with low sensitivity (1-5%).
While the consensus definition was more strongly associated with symptoms, OH definitions did not reflect natural thresholds in symptoms and were insensitive. This implies that the absence of OH using either consensus or clinical definitions does not exclude orthostatic symptoms, which has implications for evaluating clinical events like falls.
Trial Number: NCT01206062 (clinicaltrials.gov).
体位性低血压（OH）有多种定义，但这些定义与体位症状的相关性尚不清楚。
我们分析了非洲裔美国人肾脏病和高血压研究（AASK）的数据，这是一项针对高血压和肾脏病的非洲裔美国人的随机试验，以描述 OH 定义与自我报告的晕厥、头晕或头晕之间的关系。每次就诊时，在站立 2 分 45 秒后测量收缩压（SBP）、舒张压（DBP）或心率（HR）的体位变化。OH 采用共识定义（SBP 下降≥20mmHg 或 DBP 下降≥10mmHg）或基于 HR 的常用临床替代定义（增加≥20bpm）来定义。
在 1094 名参与者（平均年龄 54.5±10.7 岁，38.9%为女性）中，共进行了 52636 次就诊（平均每人 48 次）。基线时的平均静息 SBP、DBP 和 HR 分别为 147.7±22.3mmHg、92.2±13.4mmHg 和 71.1±11.7bpm。虽然 OH 共识定义与晕厥（比值比 2.49；95%置信区间：1.13，5.51）、头晕（1.89；1.53，2.33）和头晕（1.84；1.52，2.23）相关，但临床 HR 定义仅与头晕（1.28；1.07，1.52）相关。OH 的任何组成部分（SBP、DBP 或 HR）都没有反映症状的自然阈值；使用这 3 个组成部分中的每一个的定义都具有高度特异性（≥96%），但敏感性低（1-5%）。
虽然共识定义与症状的相关性更强，但 OH 定义并不能反映症状的自然阈值，而且不敏感。这意味着，无论使用共识还是临床定义，OH 的缺失都不能排除体位症状，这对评估跌倒等临床事件有影响。
试验编号：NCT01206062（clinicaltrials.gov）。
