The effect of preclinical Alzheimer's disease on age-related changes in intelligence in cognitively normal older adults
The effect of preclinical Alzheimer's disease on age-related changes in intelligence in cognitively normal older adults
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DOI：
10.1016/j.intell.2018.07.004
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发表时间：
2018-09-01
期刊：
影响因子：
3
通讯作者：
Maruff, Paul
中科院分区：
文献类型：
--
作者：
Harrington, Karra D.;Dang, Christa;Maruff, Paul
背景：对与年龄相关的正常智力功能下降的估计可能因未发现的临床前阿尔茨海默病（AD）而产生负面偏差。这项前瞻性研究旨在确定正常衰老过程中结晶智力和流体智力变化的性质和幅度，以及它们之间的相互关系，同时考虑到临床前 AD 的影响。方法：年龄在 60 至 84 岁之间的认知正常老年人 (n = 494) 在 72 个月内每隔 18 个月对流体智力和结晶智力进行系列评估，并进行 PET 神经影像检查是否存在异常淀粉样蛋白 - β (A beta+；n = 184）。使用线性混合模型分析了年龄和 Aβ+ 对液体和结晶智力变化的影响。智力差异评分是通过线性回归分析得出的，该分析对从结晶智力可以预测流体智力的程度进行了分析。评估了 Aβ 状态或临床疾病进展的智力差异评分的预测有效性。结果：相对于 Aβ- 组，Aβ+ 组表现出更大的与年龄相关的液体智力下降，但结晶智力没有下降。智力差异评分可预测进展为临床公认的疾病（即轻度认知障碍或痴呆），但与 Aβ 状态无关。结论：临床前 AD 与年龄相关的液体智力（而非结晶智力）更快下降有关。因此，流体智力和结晶智力之间的差异确实表明存在进展为早期 AD 的风险。
Background: It is possible that estimates of normal age-related decline in intellectual function have been biased negatively by undetected preclinical Alzheimer's disease (AD). This prospective study aimed to determine the nature and magnitude of changes in crystallized and fluid intelligence, as well as their relationship to one another, in normal aging, taking into account the effects of preclinical AD.Methods: Cognitively normal older adults (n = 494) aged between 60 and 84 years underwent serial assessment of fluid and crystallized intelligence at 18-month intervals over 72 months and PET neuroimaging for the presence of abnormal amyloid-beta (A beta+; n = 184). The effects of age and A beta+ on changes in fluid and crystallized intelligence were analysed using linear mixed models. An intelligence discrepancy score was developed from linear regression analysis of the extent to which fluid intelligence could be predicted from crystallized intelligence. The predictive validity of the intelligence discrepancy score for A beta status or clinical disease progression was evaluated.Results: Relative to the A beta- group, the A beta + group showed greater age-related decline on fluid, but not crystallized, intelligence. The intelligence discrepancy score predicted progression to clinically recognized disease (i.e., mild cognitive impairment or dementia), but was unrelated to A beta status.Conclusions: Preclinical AD is associated with more rapid age-related decline in fluid, but not crystallized, intelligence. Accordingly, a discrepancy between fluid and crystallized intelligence does indicate risk of progression to early AD.