Laboratory of Epidemiology and Population Sciences, National Institute on Aging, Baltimore, Maryland.
Division of Neurocritical Care, Sentara Pulmonary, Critical Care, and Sleep Specialists, Norfolk, Virginia.
JAMA Netw Open. 2022 Mar 1;5(3):e221175. doi: 10.1001/jamanetworkopen.2022.1175.
Midlife elevated blood pressure (BP) is an important risk factor associated with brain structure and function. Little is known about trajectories of BP that modulate this risk.
To identify BP trajectory patterns from young adulthood to midlife that are associated with brain structure in midlife.
DESIGN, SETTING, AND PARTICIPANTS: This cohort study used data of US adults from Coronary Artery Risk Development in Young Adults (CARDIA), a prospective longitudinal study of Black and White men and women (baseline age 18 to 30 years) examined up to 8 times over 30 years (1985-1986 to 2015-2016). There were 885 participants who underwent brain magnetic resonance imaging (MRI) in the 25th or 30th year examinations. Analyses were conducted November 2019 to December 2020.
Using group-based trajectory modeling, 5 25-year BP trajectories for 3 BP traits were identified in the total CARDIA cohort of participants with 3 or more BP measures, which were then applied to analyses of the subset of 853 participants in the Brain MRI substudy. Mean arterial pressure (MAP) was examined as an integrative measure of systolic and diastolic BP. With linear regression, the associations of the BP trajectories with brain structures were examined, adjusting sequentially for demographics, cardiovascular risk factors, and antihypertensive medication use.
Brain MRI outcomes include total brain, total gray matter, normal-looking and abnormal white matter volumes, gray matter cerebral blood flow, and white matter fractional anisotropy.
Brain MRI analyses were conducted on 853 participants (mean [SD] age, 50.3 [3.6] years; 399 [46.8%] men; 354 [41.5%] Black and 499 [58.5%] White individuals). The MAP trajectory distribution was 187 individuals (21.1%) with low-stable, 385 (43.5%) with moderate-gradual, 71 (8.0%) with moderate-increasing, 204 (23.1%) with elevated-stable, and 38 (4.3%) with elevated-increasing. Compared with the MAP low-stable trajectory group, individuals in the moderate-increasing and elevated-increasing groups were more likely to have higher abnormal white matter volume (moderate: β, 0.52; 95% CI, 0.23 to 0.82; elevated: β, 0.57; 95% CI, 0.19 to 0.95). Those in the MAP elevated-increasing group had lower gray matter cerebral blood flow (β, -0.42; 95% CI, -0.79 to -0.05) after adjusting for sociodemographics and cardiovascular risk factors. After adjustment for antihypertensive medication use, the difference was consistent for abnormal white matter volume, but results were no longer significant for gray matter cerebral blood flow.
Among young adults with moderate to high levels of BP, a gradual increase in BP to middle-age may increase the risk in diffuse small vessel disease and lower brain perfusion.
中年时期血压升高（BP）是与大脑结构和功能相关的重要风险因素。关于调节这种风险的 BP 轨迹知之甚少。
确定从青年到中年的 BP 轨迹模式，这些模式与中年时的大脑结构有关。
设计、设置和参与者：这项队列研究使用了来自美国成年人的冠状动脉风险发展在年轻人（CARDIA）的数据，这是一项对黑人和白人男性和女性（基线年龄 18 至 30 岁）进行的前瞻性纵向研究，在 30 年期间进行了多达 8 次检查（1985-1986 年至 2015-2016 年）。共有 885 名参与者在第 25 或 30 年检查中接受了脑部磁共振成像（MRI）检查。分析于 2019 年 11 月至 2020 年 12 月进行。
使用基于群组的轨迹建模，在有 3 次或更多 BP 测量的参与者的总 CARDIA 队列中确定了 3 个 BP 特征的 5 个 25 年 BP 轨迹，然后将其应用于大脑 MRI 子研究中 853 名参与者的子集中的分析。平均动脉压（MAP）被作为收缩压和舒张压的综合测量来检查。通过线性回归，检查了 BP 轨迹与大脑结构的关联，在依次调整人口统计学、心血管危险因素和抗高血压药物使用的情况下进行了调整。
脑 MRI 结果包括总脑、总灰质、正常和异常白质体积、灰质脑血流和白质各向异性分数。
对 853 名参与者（平均[SD]年龄，50.3[3.6]岁；399[46.8%]名男性；354[41.5%]名黑人，499[58.5%]名白人）进行了脑 MRI 分析。MAP 轨迹分布为 187 人（21.1%）为低稳定，385 人（43.5%）为中逐渐，71 人（8.0%）为中增加，204 人（23.1%）为高稳定，38 人（4.3%）为高增加。与 MAP 低稳定轨迹组相比，中度增加和高度增加组的个体更有可能出现更高的异常白质体积（中度：β，0.52；95%CI，0.23 至 0.82；高度：β，0.57；95%CI，0.19 至 0.95）。在调整了社会人口统计学和心血管危险因素后，MAP 高度增加组的灰质脑血流较低（β，-0.42；95%CI，-0.79 至-0.05）。在调整了抗高血压药物的使用后，异常白质体积的差异仍然存在，但灰质脑血流的结果不再显著。
在血压中度至高度的年轻人中，BP 逐渐升高到中年可能会增加弥漫性小血管疾病和大脑灌注降低的风险。
