ABSTRACT

Aging is a major risk factor for both normal and pathological cognitive decline. However, individuals vary in their rate of age-related decline. We developed an easily interpretable composite measure of cognitive age, and related both the level of cognitive age and cognitive slope to sociodemographic, genetic, and disease indicators and examined its prediction of dementia transition. Using a sample of 19,594 participants from the Health and Retirement Study, cognitive age was derived from a set of performance tests administered at each wave. Our findings reveal different conclusions as they relate to levels versus slopes of cognitive age, with more pronounced differences by sex and race/ethnicity for absolute levels of cognitive decline rather than for rates of declines. We also find that both level and slope of cognitive age are inversely related to education, as well as increased for persons with APOE Ɛ4 and/or diabetes. Finally, results show that the slope in cognitive age predicts subsequent dementia among non-demented older adults. Overall, our study suggests that this measure is applicable to cross-sectional and longitudinal studies on cognitive aging, decline, and dementia with the goal of better understanding individual differences in cognitive decline.

摘要

衰老是正常和病理性认知下降的主要危险因素。但是，个体与年龄相关的下降速度各不相同。我们开发了一种易于理解的认知年龄综合量度，并将认知年龄水平和认知斜率与社会人口统计学，遗传和疾病指标相关联，并检查了其对痴呆症转化的预测。使用来自健康与退休研究的19,594名参与者的样本，认知年龄是从每一波进行的一组性能测试得出的。我们的研究结果揭示了不同的结论，因为它们与认知年龄的水平和坡度有关，并且性别和种族/种族的性别差异对于认知能力下降的绝对水平（而不是下降速度）更为明显。我们还发现，认知年龄的水平和斜率与受教育程度成反比，对于APOE≥4和/或糖尿病的人而言，受教育程度也呈负相关。最后，结果表明认知年龄的斜率可预测非痴呆的老年人中随后的痴呆。总体而言，我们的研究表明该方法适用于有关认知衰老，衰退和痴呆的横断面和纵向研究，目的是更好地了解认知衰退中的个体差异。