Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21228;
Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21228.
Proc Natl Acad Sci U S A. 2019 Dec 10;116(50):25243-25249. doi: 10.1073/pnas.1907730116. Epub 2019 Nov 21.
Cardiovascular risk factors such as dyslipidemia and hypertension increase the risk for white matter pathology and cognitive decline. We hypothesize that white matter levels of -acetylaspartate (NAA), a chemical involved in the metabolic pathway for myelin lipid synthesis, could serve as a biomarker that tracks the influence of cardiovascular risk factors on white matter prior to emergence of clinical changes. To test this, we measured levels of NAA across white matter and gray matter in the brain using echo planar spectroscopic imaging (EPSI) in 163 individuals and examined the relationship of regional NAA levels and cardiovascular risk factors as indexed by the Framingham Cardiovascular Risk Score (FCVRS). NAA was strongly and negatively correlated with FCVRS across the brain, but, after accounting for age and sex, the association was found primarily in white matter regions, with additional effects found in the thalamus, hippocampus, and cingulate gyrus. FCVRS was also negatively correlated with creatine levels, again primarily in white matter. The results suggest that cardiovascular risks are related to neurochemistry with a predominantly white matter pattern and some subcortical and cortical gray matter involvement. NAA mapping of the brain may provide early surveillance for the potential subclinical impact of cardiovascular and metabolic risk factors on the brain.
心血管危险因素，如血脂异常和高血压，会增加白质病变和认知能力下降的风险。我们假设，-N-乙酰天门冬氨酸（NAA）的水平，一种参与髓鞘脂质合成代谢途径的化学物质，可以作为一种生物标志物，在出现临床变化之前，跟踪心血管危险因素对白质的影响。为了验证这一点，我们使用磁共振波谱成像（MRS）在 163 名个体的大脑中测量了 NAA 水平，并检查了 NAA 水平与心血管风险因素（以弗雷明汉心血管风险评分（Framingham Cardiovascular Risk Score，FCVRS）为指标）之间的关系。NAA 与 FCVRS 在大脑中呈强烈的负相关，但在考虑年龄和性别后，这种关联主要出现在白质区域，在丘脑、海马体和扣带回也有额外的影响。FCVRS 也与肌酸水平呈负相关，这主要也是在白质中。结果表明，心血管风险与以白质为主的神经化学有关，并有一些皮质下和皮质灰质的参与。大脑的 NAA 图谱可能为心血管和代谢危险因素对大脑潜在的亚临床影响提供早期监测。
