Introduction

Stroke and Alzheimer disease share risk factors and often co-occur, and both have been reported to have a higher prevalence in African Americans as compared to non-Hispanic whites. However, their interaction has not been established. The objective of this study was to determine if preclinical Alzheimer disease is a risk factor for stroke and post-stroke dementia and whether racial differences moderate this relationship.

Methods

This case-control study was analyzed in 2019 using retrospective data from 2007 to 2013. Participants were adults age 65 and older with and without acute ischemic stroke. Recruitment included word of mouth and referrals in Saint Louis, MO, with stroke participants recruited from acutely hospitalized patients and non-stroke participants from community living older adults who were research volunteers. Our assessment included radiologic reads of infarcts, microbleeds, and white matter hyperintensitites (WMH); a Pittsburgh Compound B PET measure of cortical β-amyloid binding; quantitative measures of hippocampal and WMH volume; longitudinal Mini Mental State Examination (MMSE) scores; and Clinical Dementia Rating (CDR) 1 year post-stroke.

Results

A total of 243 participants were enrolled, 81 of which had a recent ischemic stroke. Participants had a mean age of 75, 57% were women, and 52% were African American. Cortical amyloid did not differ significantly by race, stroke status, or CDR post-stroke. There were racial differences in MMSE scores at baseline (mean 26.8 for African Americans, 27.9 for non-Hispanic whites, p = 0.03), but not longitudinally. African Americans were more likely to have microbleeds (32.8% vs 22.6%, p = 0.04), and within the acute stroke group, African Americans were more likely to have small infarcts (75.6% vs 56.8%, p = 0.049).

Conclusion

Preclinical Alzheimer disease did not show evidence of being a risk factor for stroke nor predictive of post-stroke dementia. We did not observe racial differences in β-amyloid levels. However, even after controlling for several vascular risk factors, African Americans with clinical stroke presentations had greater levels of vascular pathology on MRI.

中文翻译：

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急性中风、中风后痴呆、种族和 β-淀粉样蛋白状态之间缺乏关联

 介绍

中风和阿尔茨海默病有共同的危险因素，并且经常同时发生，据报道，与非西班牙裔白人相比，这两种疾病在非裔美国人中的患病率更高。然而，他们的相互作用尚未建立。本研究的目的是确定临床前阿尔茨海默病是否是中风和中风后痴呆的危险因素，以及种族差异是否会调节这种关系。

 方法

这项病例对照研究于 2019 年使用 2007 年至 2013 年的回顾性数据进行了分析。参与者是 65 岁及以上的成年人，患有或不患有急性缺血性中风。招募包括密苏里州圣路易斯的口碑和推荐，中风参与者是从急性住院患者中招募的，非中风参与者是从社区老年人中招募的，他们是研究志愿者。我们的评估包括梗塞、微出血和白质高信号 (WMH) 的放射学读数；匹兹堡化合物 B PET 测量皮质 β-淀粉样蛋白结合；海马和 WMH 体积的定量测量；纵向简易精神状态检查（MMSE）分数；和中风后 1 年的临床痴呆评级 (CDR)。

 结果

共有 243 名参与者入组，其中 81 人最近患有缺血性中风。参与者的平均年龄为 75 岁，其中 57% 是女性，52% 是非裔美国人。皮质淀粉样蛋白在种族、中风状态或中风后 CDR 方面没有显着差异。基线时 MMSE 分数存在种族差异（非洲裔美国人平均为 26.8，非西班牙裔白人平均为 27.9， p = 0.03），但纵向上没有差异。非裔美国人更有可能出现微出血（32.8% vs 22.6%， p = 0.04），而在急性卒中组中，非裔美国人更有可能出现小梗塞（75.6% vs 56.8%， p = 0.049）。

 结论

临床前阿尔茨海默病没有证据表明它是中风的危险因素，也没有证据表明它可以预测中风后痴呆。我们没有观察到β-淀粉样蛋白水平的种族差异。然而，即使在控制了几种血管危险因素后，具有临床卒中表现的非裔美国人在 MRI 上的血管病理水平也更高。