Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts; Department of Epidemiology, Erasmus MC University Medical Center, Rotterdam, the Netherlands.
Department of Epidemiology, Erasmus MC University Medical Center, Rotterdam, the Netherlands; Department of Radiology and Nuclear Medicine, Erasmus MC University Medical Center, Rotterdam, the Netherlands.
J Am Coll Cardiol. 2020 May 19;75(19):2387-2399. doi: 10.1016/j.jacc.2020.03.043.
Large blood pressure (BP) variability may contribute to stroke and dementia, but the mechanisms are largely unknown.
This study investigated the association of BP variation, considering its magnitude and direction, with the presence and progression of subclinical brain disease in the general population.
This study included 2,348 participants age ≥55 years from a prospective cohort study. BP was measured at each visit every 3 to 4 years from 1990 onward. Brain magnetic resonance imaging (MRI) was performed at all visits from 2005 onward. The authors primarily assessed variation as the absolute difference in BP divided by the mean over 2 sequential visits for both systolic BP (SBP) and diastolic BP (DBP), and further assessed the direction of the variation. The authors investigated the multivariate-adjusted associations of BP variation with subsequent measurements of MRI markers of cerebral small vessel disease, brain tissue volumes, and white matter microstructural integrity. Longitudinal changes in these markers also were assessed.
A large SBP variation (top vs. bottom tertiles), measured on average 7 years preceding brain MRI, was associated with higher odds of having severe white matter hyperintensities (WMH) (odds ratio [OR]: 1.32; 95% confidence interval [CI]: 1.21 to 1.43), lacunes (OR: 1.25; 95% CI: 1.04 to 1.48), and microbleeds (OR: 1.16; 95% CI: 1.03 to 1.31). Similarly, this variation was associated with smaller total brain volume and worse white matter microstructural integrity (all p < 0.001). A large SBP variation was also associated with the progression of WMH (rate ratio [RR]: 1.14; 95% CI: 1.02 to 1.27). Higher burdens of these brain imaging markers were observed with both large rises and falls in SBP. Similar findings were observed for DBP variation.
Elevated BP variation was associated with a wide range of subclinical brain structural changes, including MRI markers of cerebral small vessel disease, smaller brain tissue volumes, and worse white matter microstructural integrity. These subclinical brain changes could be the underlying mechanisms linking BP variation to dementia and stroke.
血压（BP）的大幅波动可能导致中风和痴呆，但其中的机制尚不清楚。
本研究旨在调查一般人群中 BP 波动幅度和方向与亚临床脑部疾病的发生和进展之间的关联。
本研究纳入了 1990 年起每 3 至 4 年进行一次随访的前瞻性队列研究中的 2348 名年龄≥55 岁的参与者。自 2005 年起，所有参与者每次就诊时都进行脑磁共振成像（MRI）检查。本研究主要评估了收缩压（SBP）和舒张压（DBP）在两次连续就诊期间的平均血压差异除以平均血压的绝对值，进一步评估了变异的方向。作者还研究了 BP 变异与后续 MRI 脑小血管疾病标志物、脑实质体积和白质微观结构完整性测量值之间的多变量调整关联。还评估了这些标志物的纵向变化。
在 MRI 检查前平均 7 年测量的较大 SBP 波动（最高与最低三分位数）与较高的严重白质高信号（WMH）（比值比[OR]：1.32；95%置信区间[CI]：1.21 至 1.43）、腔隙（OR：1.25；95%CI：1.04 至 1.48）和微出血（OR：1.16；95%CI：1.03 至 1.31）发生风险相关。同样，这种波动也与总脑容量减少和白质微观结构完整性恶化有关（均 p<0.001）。较大的 SBP 波动还与 WMH 的进展相关（速率比[RR]：1.14；95%CI：1.02 至 1.27）。较高的 SBP 升高和降低都与这些脑影像学标志物的负担增加有关。DBP 变化也有类似的发现。
BP 波动幅度升高与广泛的亚临床脑结构变化相关，包括脑小血管疾病的 MRI 标志物、脑实质体积减少和白质微观结构完整性恶化。这些亚临床脑变化可能是将 BP 波动与痴呆和中风联系起来的潜在机制。
