Stroke Prevention Research Unit, University Department of Clinical Neurology, John Radcliffe Hospital, Oxford, UK.
Lancet. 2010 Mar 13;375(9718):906-15. doi: 10.1016/S0140-6736(10)60235-8.
Unexplained differences between classes of antihypertensive drugs in their effectiveness in preventing stroke might be due to class effects on intraindividual variability in blood pressure. We did a systematic review to assess any such effects in randomised controlled trials.
Baseline and follow-up data for mean (SD) of systolic blood pressure (SBP) were extracted from trial reports. Effect of treatment on interindividual variance (SD2) in blood pressure (a surrogate for within-individual variability), expressed as the ratio of the variances (VR), was related to effects on clinical outcomes. Pooled estimates were derived by use of random-effects meta-analysis.
Mean (SD) SBP at follow-up was reported in 389 (28%) of 1372 eligible trials. There was substantial heterogeneity between trials in VR (p<1 x 10(-40)), 68% of which was attributable to allocated drug class. Compared with other drugs, interindividual variation in SBP was reduced by calcium-channel blockers (VR 0.81, 95% CI 0.76-0.86, p<0.0001) and non-loop diuretic drugs (0.87, 0.79-0.96, p=0.007), and increased by angiotensin-converting enzyme (ACE) inhibitors (1.08, 1.02-1.15, p=0.008), angiotensin-receptor blockers (1.16, 1.07-1.25, p=0.0002), and beta blockers (1.17, 1.07-1.28, p=0.0007). Compared with placebo only, interindividual variation in SBP was reduced the most by calcium-channel blockers (0.76, 0.67-0.85, p<0.0001). Effects were consistent in parallel group and crossover design trials, and in analyses of dose-response. Across all trials, effects of treatment on VR of SBP (r2=0.372, p=0.0006) and on mean SBP (r2=0.328, p=0.0015) accounted for effects on stroke risk (eg, odds ratio 0.79, 0.71-0.87, p<0.0001, for VR< or =0.80), and both remained significant in a combined model.
Drug-class effects on interindividual variation in blood pressure can account for differences in effects of antihypertensive drugs on risk of stroke independently of effects on mean SBP.
None.
抗高血压药物在预防中风方面的疗效存在未明的差异，这可能是由于药物类别对血压个体内变异性的影响。我们进行了一项系统综述，以评估随机对照试验中是否存在此类影响。
从试验报告中提取收缩压（SBP）的平均值（SD）和基线及随访时的平均（SD）数据。治疗对血压个体内变异（SD2）的影响（用方差比（VR）表示，是个体内变异性的替代指标）与临床结局的影响有关。通过使用随机效应荟萃分析得出汇总估计值。
在 1372 项符合条件的试验中，有 389 项（28%）报告了随访时的平均（SD）SBP。试验间 VR 存在很大的异质性（p<1 x 10(-40)），其中 68%归因于分配的药物类别。与其他药物相比，钙通道阻滞剂（VR 0.81，95%CI 0.76-0.86，p<0.0001）和非噻嗪类利尿剂（0.87，0.79-0.96，p=0.007）降低了 SBP 的个体内变异性，而血管紧张素转换酶（ACE）抑制剂（1.08，1.02-1.15，p=0.008）、血管紧张素受体阻滞剂（1.16，1.07-1.25，p=0.0002）和β受体阻滞剂（1.17，1.07-1.28，p=0.0007）则增加了 SBP 的个体内变异性。与安慰剂相比，钙通道阻滞剂对 SBP 的个体内变异性的降低最为显著（0.76，0.67-0.85，p<0.0001）。平行组和交叉设计试验以及剂量-反应分析的结果一致。在所有试验中，治疗对 SBP 的 VR（r2=0.372，p=0.0006）和平均 SBP（r2=0.328，p=0.0015）的影响与中风风险的影响（例如，VR<或=0.80 的比值比为 0.79，0.71-0.87，p<0.0001）有关，并且在综合模型中两者仍然具有统计学意义。
药物类别对血压个体内变异性的影响可以解释降压药物对中风风险的影响，而不依赖于对平均 SBP 的影响。
药物类别对血压个体内变异性的影响可以解释降压药物在预防中风方面的疗效差异，而与平均 SBP 的影响无关。
无。
