Plassman B L, Welsh K A, Helms M, Brandt J, Page W F, Breitner J C
Department of Psychiatry, Duke University Medical Center, Durham, NC, USA.
Neurology. 1995 Aug;45(8):1446-50. doi: 10.1212/wnl.45.8.1446.
We evaluated the relation of education and intelligence in early adult life to cognitive function in a group of elderly male twins. The Army General Classification Test (AGCT) was administered to US armed forces inductees in the early 1940s. Fifty years later, as part of a study of dementia in twins, we tested the cognitive status of 930 of these men using the modified Telephone Interview for Cognitive Status (TICS-m). TICS-m scores obtained in later life were correlated with AGCT scores (r = 0.457) and with years of education (r = 0.408). Thus, in univariate analyses, the AGCT score accounted for 20.6% and education accounted for 16.7% of variance in cognitive status. However, these two effects were not fully independent. A multivariable model using AGCT score, education, and the interaction of the two variables as predictors of the TICS-m score explained 24.8% of the variance, a slightly but significantly greater proportion than was explained by either factor alone. In a separate analysis based on 604 pairs of twins who took the AGCT, heritability of intelligence (estimated by AGCT score) was 0.503. Although this study does not address the issue of education and premorbid IQ as risk factors for dementia, the findings suggest that basic cognitive abilities in late life are related to cognitive performance measures from early adult life (ie, education and IQ).
我们评估了一组老年男性双胞胎在成年早期的教育和智力与认知功能之间的关系。20世纪40年代初，美国武装部队新兵接受了陆军普通分类测试（AGCT）。50年后，作为一项双胞胎痴呆症研究的一部分，我们使用改良的认知状态电话访谈（TICS-m）对其中930名男性的认知状况进行了测试。晚年获得的TICS-m分数与AGCT分数（r = 0.457）以及受教育年限（r = 0.408）相关。因此，在单变量分析中，AGCT分数占认知状态方差的20.6%，教育占16.7%。然而，这两种效应并非完全独立。一个使用AGCT分数、教育程度以及这两个变量的相互作用作为TICS-m分数预测因子的多变量模型解释了24.8%的方差，这一比任何一个因素单独解释的比例略高但显著更高。在一项基于604对参加AGCT的双胞胎的单独分析中，智力的遗传度（通过AGCT分数估计）为0.503。尽管这项研究没有涉及教育和病前智商作为痴呆症风险因素的问题，但研究结果表明，晚年的基本认知能力与成年早期的认知表现指标（即教育和智商）有关。
