Center for Brain Imaging and Neuromodulation, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, USA; Department of Psychiatry, New York University School of Medicine, New York, NY, USA.
Center for Brain Imaging and Neuromodulation, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, USA.
Psychiatry Res Neuroimaging. 2020 Jul 30;301:111107. doi: 10.1016/j.pscychresns.2020.111107. Epub 2020 May 14.
Early detection of Alzheimer's disease (AD) is important for timely interventions and developing new treatments. Hippocampus atrophy is an early biomarker of AD. The hippocampal parenchymal fraction (HPF) is a promising measure of hippocampal structural integrity computed from structural MRI. It is important to characterize the dependence of HPF on covariates such as age and sex in the normal population to enhance its utility as a disease biomarker. We measured the HPF in 4239 structural MRI scans from 340 cognitively normal (CN) subjects aged 59-89 years from the AD Neuroimaging Initiative database, and studied its dependence on age, sex, apolipoprotein E (APOE) genotype, brain hemisphere, intracranial volume (ICV), and education using a linear mixed-effects model. In this CN cohort, HPF was inversely associated with ICV; was greater on the right hemisphere compared to left in both sexes with the degree of right > left asymmetry being slightly more pronounced in men; declined quadratically with age and faster in APOE ϵ4 carriers compared to non-carriers; and was significantly associated with cognitive ability. Consideration of HPF as an AD biomarker should be in conjunction with other subject attributes that are shown in this research to influence HPF levels in CN older individuals.
早期发现阿尔茨海默病（AD）对于及时干预和开发新的治疗方法非常重要。海马萎缩是 AD 的早期生物标志物。海马实质分数（HPF）是一种有前途的测量方法，可通过结构 MRI 计算出海马的结构完整性。重要的是要描述 HPF 在正常人群中对年龄和性别等协变量的依赖性，以增强其作为疾病生物标志物的效用。我们从 AD 神经影像学倡议数据库中测量了 340 名认知正常（CN）受试者的 4239 个结构 MRI 扫描中的 HPF，这些受试者年龄在 59-89 岁之间，并使用线性混合效应模型研究了其对年龄、性别、载脂蛋白 E（APOE）基因型、脑半球、颅内体积（ICV）和教育的依赖性。在这个 CN 队列中，HPF 与 ICV 呈负相关；在两性中，右半球的 HPF 大于左半球，右半球的左右不对称程度在男性中略为明显；与年龄呈二次方关系，APOE ϵ4 携带者的下降速度快于非携带者；并且与认知能力显著相关。在 CN 老年人中，考虑将 HPF 作为 AD 生物标志物时，应结合本研究中显示会影响 HPF 水平的其他受试者属性。
