Department of Radiology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA.
Ann Neurol. 2013 Jun;73(6):751-61. doi: 10.1002/ana.23797. Epub 2013 Apr 17.
This study examined amyloid-β (Aβ) deposition in 190 nondemented subjects aged ≥82 years to determine the proportion of Aβ-positive scans and associations with cognition, apolipoprotein E (APOE) status, brain volume, and Ginkgo biloba (Gb) treatment.
Subjects who agreed to participate had a brain magnetic resonance imaging and positron emission tomography scan with (11) C-labeled Pittsburgh compound B (PiB) following completion of a Gb treatment clinical trial. The youngest subject in this imaging study was 82 years, and the mean age of the subjects was 85.5 years at the time of the scans; 152 (80%) were cognitively normal, and 38 (20%) were diagnosed with mild cognitive impairment (MCI) at the time of the PiB study.
A high proportion of the cognitively normal subjects (51%) and MCI subjects (68%) were PiB-positive. The APOE*4 allele was more prevalent in PiB-positive than in PiB-negative subjects (30% vs 6%). Measures of memory, language, and attentional functions were worse in PiB-positive than in PiB-negative subjects, when both normal and MCI cases were analyzed together; however, no significant associations were observed within either normal or MCI subject groups alone. There was no relationship between Gb treatment and Aβ deposition as determined by PiB.
The data revealed a 55% prevalence of PiB positivity in nondemented subjects age >80 years and 85% PiB positivity in the APOE*4 nondemented elderly subjects. The findings also showed that long-term exposure to Gb did not affect the prevalence of cerebral Aβ deposition.
本研究检测了 190 名年龄≥82 岁、无痴呆的受试者的淀粉样蛋白-β（Aβ）沉积情况，以确定 Aβ 阳性扫描的比例，并探讨其与认知、载脂蛋白 E（APOE）状态、脑容量和银杏叶提取物（Gb）治疗的关系。
同意参与的受试者完成银杏叶提取物治疗临床试验后，接受脑磁共振成像和正电子发射断层扫描，并使用（11）C 标记的匹兹堡化合物 B（PiB）。这项影像学研究中最年轻的受试者为 82 岁，受试者接受扫描时的平均年龄为 85.5 岁；152 名（80%）认知正常，38 名（20%）在 PiB 研究时被诊断为轻度认知障碍（MCI）。
认知正常受试者（51%）和 MCI 受试者（68%）中有很大比例的 PiB 阳性。APOE*4 等位基因在 PiB 阳性受试者中比 PiB 阴性受试者更常见（30%比 6%）。当正常和 MCI 病例一起分析时，PiB 阳性受试者的记忆、语言和注意力功能等指标比 PiB 阴性受试者差；然而，在单独的正常或 MCI 受试者组中，未观察到显著的相关性。PiB 未能确定银杏叶提取物治疗与 Aβ 沉积之间存在关系。
数据显示，80 岁以上无痴呆的受试者中 PiB 阳性的患病率为 55%，APOE*4 无痴呆的老年受试者中 PiB 阳性的患病率为 85%。研究结果还表明，长期接触银杏叶提取物不会影响大脑 Aβ 沉积的患病率。
