Nyquist Paul A, Bilgel Murat S, Gottesman Rebecca, Yanek Lisa R, Moy Taryn F, Becker Lewis C, Cuzzocreo Jennifer, Prince Jerry, Yousem David M, Becker Diane M, Kral Brian G, Vaidya Dhananjay
Department of Neurology, Johns Hopkins School of Medicine, Baltimore, Md., USA.
Cerebrovasc Dis. 2014;37(4):244-50. doi: 10.1159/000358117. Epub 2014 Mar 25.
African Americans (AAs) have a higher prevalence of extreme ischemic white matter hyperintensities (WMHs) on magnetic resonance imaging (MRI) than do European Americans (EAs) based on the Cardiovascular Health Study (CHS) score. Ischemic white matter disease, limited to the deep white matter, may be biologically distinct from disease in other regions and may reflect a previously observed trend toward an increased risk of subcortical lacunar infarcts in AAs. We hypothesized that extreme deep WMH volume (DWMV) or periventricular volume (PV) may also have a higher prevalence in AAs. Thus, we studied extreme CHS scores and extreme DWMV and PV in a healthy population enriched for cardiovascular disease risk factors.
We imaged the brains of 593 subjects who were first-degree relatives of probands with early onset coronary disease prior to 60 years of age. WMHs were manually delineated on 3-tesla cranial MRI by a trained radiology reader; the location and volume of lesions were characterized using automated software. DWMV and PV were measured directly with automated software, and the CHS score was determined by a neuroradiologist. Volumes were characterized as being in the upper 25% versus lower 75% of total lesion volume. Volumes in the upper versus the remaining quartiles were examined for AA versus EA race using multiple logistic regression (generalized estimating equations adjusted for family relatedness) and adjusted for major vascular disease risk factors including age ≥55 years versus <55, sex, current smoking, obesity, hypertension, diabetes and low-density lipoprotein >160 mg/dl.
Participants were 58% women and 37% AAs, with a mean age of 51.5 ± 11.0 years (range, 29-74 years). AAs had significantly higher odds of having extreme DWMVs (odds ratio, OR, 1.8; 95% confidence interval, CI, 1.2-2.9; p = 0.0076) independently of age, sex, hypertension and all other risk factors. AAs also had significantly higher odds of having extreme CHS scores ≥3 (OR, 1.3; 95% CI, 1.1-3.6; p = 0.025). Extreme PV was not significantly associated with AA race (OR, 1.3; 95% CI, 0.81-2.1; p = 0.26).
AAs from families with early-onset cardiovascular disease are more likely to have extreme DWMVs (a subclinical form of cerebrovascular disease) and an extreme CHS score, but not extreme PV, independently of age and other cardiovascular disease risk factors. These findings suggest that this AA population is at an increased risk for DWMV and may be at an increased risk for future subcortical stroke. Longitudinal studies are required to see if DWMV is predictive of symptomatic subcortical strokes in this population.
基于心血管健康研究（CHS）评分，非裔美国人（AA）在磁共振成像（MRI）上出现极端缺血性脑白质高信号（WMH）的患病率高于欧裔美国人（EA）。局限于深部白质的缺血性白质疾病在生物学上可能与其他区域的疾病不同，并且可能反映了之前观察到的非裔美国人皮质下腔隙性梗死风险增加的趋势。我们推测，极端深部WMH体积（DWMV）或脑室周围体积（PV）在非裔美国人中的患病率可能也更高。因此，我们在一个富含心血管疾病风险因素的健康人群中研究了极端CHS评分以及极端DWMV和PV。
我们对593名受试者的大脑进行了成像，这些受试者是60岁之前患早发性冠心病先证者的一级亲属。由一名经过培训的放射科阅片者在3特斯拉头颅MRI上手动勾勒出WMH；使用自动化软件对病变的位置和体积进行特征描述。通过自动化软件直接测量DWMV和PV，由神经放射科医生确定CHS评分。将体积特征化为占总病变体积的上25%与下75%。使用多因素逻辑回归（针对家族相关性进行调整的广义估计方程），并针对包括年龄≥55岁与<55岁、性别、当前吸烟、肥胖、高血压、糖尿病以及低密度脂蛋白>160mg/dl在内的主要血管疾病风险因素进行调整，比较非裔美国人与欧裔美国人种族中体积处于上四分位数与其余四分位数的情况。
参与者中58%为女性，37%为非裔美国人，平均年龄为51.5±11.0岁（范围为29 - 74岁）。独立于年龄、性别、高血压和所有其他风险因素，非裔美国人出现极端DWMV的几率显著更高（优势比，OR，1.8；95%置信区间，CI，1.2 - 2.9；p = 0.0076）。非裔美国人出现极端CHS评分≥3的几率也显著更高（OR，1.3；95% CI，1.1 - 3.6；p = 0.025）。极端PV与非裔美国人种族无显著关联（OR，1.3；95% CI，0.81 - 2.1；p = 0.26）。
来自早发性心血管疾病家族的非裔美国人更有可能出现极端DWMV（一种脑血管疾病的亚临床形式）和极端CHS评分，但不会出现极端PV，且独立于年龄和其他心血管疾病风险因素。这些发现表明，这一非裔美国人人群发生DWMV的风险增加，并且未来发生皮质下卒中的风险可能也会增加。需要进行纵向研究以确定DWMV是否可预测该人群中的症状性皮质下卒中。
