Center for the Study of Human Cognition, Department of Psychology, University of Oslo, Oslo, Norway.
Cereb Cortex. 2010 Sep;20(9):2069-79. doi: 10.1093/cercor/bhp279. Epub 2010 Jan 4.
Reduced levels of beta-amyloid(1-42) (Abeta1-42) and increased levels of tau proteins in the cerebrospinal fluid (CSF) are found in Alzheimer's disease (AD), likely reflecting Abeta deposition in plaques and neuronal and axonal damage. It is not known whether these biomarkers are associated with brain atrophy also in healthy aging. We tested the relationship between CSF levels of Abeta1-42 and tau (total tau and tau phosphorylated at threonine 181) proteins and 1-year brain atrophy in 71 cognitively normal elderly individuals. Results showed that under a certain threshold value, levels of Abeta1-42 correlated highly with 1-year change in a wide range of brain areas. The strongest relationships were not found in the regions most vulnerable early in AD. Above the threshold level, Abeta1-42 was not related to brain changes, but significant volume reductions as well as ventricular expansion were still seen. It is concluded that Abeta1-42 correlates with brain atrophy and ventricular expansion in a subgroup of cognitively normal elderly individuals but that reductions independent of CSF levels of Abeta1-42 is common. Further research and follow-up examinations over several years are needed to test whether degenerative pathology will eventually develop in the group of cognitively normal elderly individuals with low levels of Abeta1-42.
脑脊液（CSF）中β-淀粉样蛋白（1-42）（Abeta1-42）水平降低和tau 蛋白水平升高与阿尔茨海默病（AD）有关，可能反映了斑块中的 Abeta 沉积以及神经元和轴突损伤。目前尚不清楚这些生物标志物是否与健康衰老时的脑萎缩有关。我们在 71 名认知正常的老年人中测试了 CSF 中 Abeta1-42 和 tau（总 tau 和在苏氨酸 181 处磷酸化的 tau）蛋白水平与 1 年脑萎缩之间的关系。结果表明，在一定的阈值下，Abeta1-42 水平与广泛脑区的 1 年变化高度相关。最强的相关性并非出现在 AD 早期最易受损的区域。在阈值以上，Abeta1-42 与脑变化无关，但仍可见明显的体积减少和脑室扩张。结论是，Abeta1-42 与认知正常老年人亚组的脑萎缩和脑室扩张相关，但独立于 CSF Abeta1-42 水平的减少很常见。需要进一步的研究和多年的随访检查，以测试 Abeta1-42 水平较低的认知正常老年人组是否最终会出现退行性病理。
