Department of Psychology University of Southern California Los Angeles CA.
Institute for Memory Impairments and Neurological Disorders University of California Irvine Irvine CA.
J Am Heart Assoc. 2023 Jun 20;12(12):e029797. doi: 10.1161/JAHA.123.029797. Epub 2023 Jun 10.
Background Blood pressure variability (BPV) is predictive of cerebrovascular disease and dementia, possibly though cerebral hypoperfusion. Higher BPV is associated with cerebral blood flow (CBF) decline in observational cohorts, but relationships in samples with strictly controlled blood pressure remain understudied. We investigated whether BPV relates to change in CBF in the context of intensive versus standard antihypertensive treatment. Methods and Results In this post hoc analysis of the SPRINT MIND (Systolic Blood Pressure Intervention Trial-Memory and Cognition in Decreased Hypertension) trial, 289 participants (mean, 67.6 [7.6 SD] years, 38.8% women) underwent 4 blood pressure measurements over a 9-month period after treatment randomization (intensive versus standard) and pseudo-continuous arterial spin labeling magnetic resonance imaging at baseline and ≈4-year follow-up. BPV was calculated as tertiles of variability independent of mean. CBF was determined for whole brain, gray matter, white matter, hippocampus, parahippocampal gyrus, and entorhinal cortex. Linear mixed models examined relationships between BPV and change in CBF under intensive versus standard antihypertensive treatment. Higher BPV in the standard treatment group was associated with CBF decline in all regions (ß comparing the first versus third tertiles of BPV in whole brain: -0.09 [95% CI, -0.17 to -0.01]; =0.03), especially in medial temporal regions. In the intensive treatment group, elevated BPV was related to CBF decline only in the hippocampus (ß, -0.10 [95% CI, -0.18, -0.01]; =0.03). Conclusions Elevated BPV is associated with CBF decline, especially under standard blood pressure-lowering strategies. Relationships were particularly robust in medial temporal regions, consistent with prior work using observational cohorts. Findings highlight the possibility that BPV remains a risk for CBF decline even in individuals with strictly controlled mean blood pressure levels. Registration URL: http://clinicaltrials.gov. Identifier: NCT01206062.
背景 血压变异性（BPV）可预测脑血管病和痴呆，可能与脑灌注不足有关。在观察性队列中，较高的 BPV 与脑血流（CBF）下降相关，但在血压严格控制的样本中，这些关系仍研究不足。我们研究了在强化与标准降压治疗的情况下，BPV 是否与 CBF 的变化有关。
方法和结果 在 SPRINT MIND（收缩压干预试验-降低高血压的记忆和认知）试验的事后分析中，289 名参与者（平均年龄 67.6 [7.6 标准差] 岁，38.8%为女性）在治疗随机分组（强化与标准）后 9 个月内进行了 4 次血压测量，并在基线和 ≈4 年随访时进行了假性连续动脉自旋标记磁共振成像。BPV 作为独立于均值的变异性的三分位数进行计算。为全脑、灰质、白质、海马、海马旁回和内嗅皮层确定了 CBF。线性混合模型检查了强化与标准降压治疗下 BPV 与 CBF 变化之间的关系。标准治疗组中较高的 BPV 与所有区域的 CBF 下降相关（全脑比较 BPV 第一三分位与第三三分位：-0.09 [95%CI，-0.17 至 -0.01]；=0.03），特别是在颞叶内侧区域。在强化治疗组中，较高的 BPV 仅与海马的 CBF 下降有关（-0.10 [95%CI，-0.18 至 -0.01]；=0.03）。
结论 较高的 BPV 与 CBF 下降有关，尤其是在标准降压策略下。这些关系在颞叶内侧区域尤为显著，与使用观察性队列的先前工作一致。这些发现强调了即使在血压严格控制的个体中，BPV 仍然是 CBF 下降的一个风险因素。
