Laboratory of Behavioral Neuroscience National Institute on AgingIntramural Research Program Baltimore MD.
Department of Medicine SUNY Downstate Health Sciences University Brooklyn NY.
J Am Heart Assoc. 2021 Sep 7;10(17):e022087. doi: 10.1161/JAHA.121.022087. Epub 2021 Aug 25.
Background White matter abnormalities are a common feature of aging and Alzheimer disease, and tend to be more severe among Black individuals. However, the extent to which white matter abnormalities relate to amyloid deposition, a marker of Alzheimer pathology, remains unclear. This cross-sectional study examined the association of white matter abnormalities with cortical amyloid in a community sample of older adults without dementia and examined the moderating effect of race. Methods and Results Participants from the ARIC-PET (Atherosclerosis Risk in Communities-Positron Emission Tomography) study underwent brain magnetic resonance imaging, which quantified white matter hyperintensity volume and microstructural integrity using diffusion tensor imaging. Participants received florbetapir positron emission tomography imaging to measure brain amyloid. Associations between measures of white matter structure and elevated amyloid status were examined using multivariable logistic regression. Among 322 participants (43% Black), each SD increase in white matter hyperintensity volume was associated with a greater odds of elevated amyloid (odds ratio [OR], 1.37; 95% CI, 1.03-1.83) after adjusting for demographic and cardiovascular risk factors. In race-stratified analyses, a greater white matter hyperintensity volume was more strongly associated with elevated amyloid among Black participants (OR, 2.00; 95% CI, 1.15-3.50), compared with White participants (OR, 1.29; 95% CI, 0.89-1.89). However, the race interaction was not statistically significant ( interaction=0.09). We found no association between white matter microstructure and elevated amyloid. Conclusions The results suggest a modest positive relationship between white matter hyperintensity and elevated amyloid in older adults without dementia. Although the results indicate that this association is nonsignificantly stronger among Black participants, these findings will need to be confirmed or refuted using larger multiracial cohorts.
背景
脑白质异常是衰老和阿尔茨海默病的常见特征，且在黑人群体中更为严重。然而，脑白质异常与淀粉样蛋白沉积（阿尔茨海默病病理的标志物）之间的关联程度仍不清楚。本横断面研究在无痴呆的老年社区样本中检查了脑白质异常与皮质淀粉样蛋白之间的关联，并检验了种族的调节作用。
方法和结果
ARIC-PET（社区动脉粥样硬化风险研究-正电子发射断层扫描）研究的参与者接受了脑部磁共振成像，该成像使用弥散张量成像量化了脑白质高信号体积和微观结构完整性。参与者接受了氟比他滨正电子发射断层扫描成像，以测量脑内淀粉样蛋白。使用多变量逻辑回归检验脑白质结构测量值与淀粉样蛋白升高状态之间的关联。在 322 名参与者（43%为黑人）中，在调整了人口统计学和心血管危险因素后，脑白质高信号体积每增加一个标准差，与淀粉样蛋白升高的几率增加相关（比值比[OR]，1.37；95%置信区间[CI]，1.03-1.83）。在按种族分层的分析中，与白种参与者（OR，1.29；95%CI，0.89-1.89）相比，脑白质高信号体积较大与黑人参与者中淀粉样蛋白升高的关联更强（OR，2.00；95%CI，1.15-3.50）。然而，种族间的相互作用没有统计学意义（交互作用=0.09）。我们没有发现脑白质微观结构与淀粉样蛋白升高之间的关联。
结论
这些结果表明，在无痴呆的老年人群中，脑白质高信号与淀粉样蛋白升高之间存在适度的正相关。尽管这些结果表明，这种关联在黑人参与者中更强，但这些发现需要使用更大的多种族队列来证实或反驳。
