School of Public Health and Management, Chongqing Medical University, Chongqing, 400016, P. R. China.
Research Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London, WC1E 6BT, UK.
BMC Public Health. 2022 Feb 4;22(1):231. doi: 10.1186/s12889-022-12671-6.
Cognitive reserve (CR) could partly explain the individual heterogeneity in cognitive decline. No study measured CR from a life course perspective and investigated the association between CR and trajectories of cognitive decline in older Chinese adults.
Data of 6795 Chinese adults aged 60+ from China Health and Retirement Longitudinal Study were used. Global cognition score (0-32) was assessed in all four waves. A life-course CR score was constructed using markers of childhood circumstance, education, highest occupational class, and leisure activities in later life. Latent growth curve modelling (LGCM) was applied to assess the association between CR and trajectories of cognitive decline.
For the life-course CR, factor loadings of markers in adulthood and later life were larger than that of markers in childhood. The life-course CR score (ranged between - 2.727 and 6.537, SD: 1.74) was higher in urban Chinese adults (0.75, SD: 1.90) than in rural Chinese adults (- 0.50, SD: 1.43). The unconditional LGCM results showed that urban older Chinese adults had better global cognition at baseline (intercept: 15.010, 95% CI: 14.783, 15.237) and a slower rate of cognitive decline per year (linear slope: -0.394, 95% CI: - 0.508, - 0.281) than their rural counterparts (intercept: 12.144, 95% CI: 11.960, 12.329; linear slope: -0.498, 95% CI: - 0.588, - 0.408). After controlling for all covariates, one-unit higher CR score was associated with 1.615 (95% CI: 1.521, 1.709) and 1.768 (95% CI: 1.659, 1.876) unit higher global cognition at baseline for urban and rural older Chinese adults, respectively. The slower rate of cognitive decline associated with higher CR was more evident in rural residents (slope: 0.083, 95% CI: 0.057, 0.108) than in their urban counterparts (0.054, 95% CI: 0.031, 0.077).
CR was associated with better baseline cognition and slower cognitive decline in Chinese older adults. Although rural residents were disadvantaged in both CR and cognition, the protective effect of CR against cognitive decline was stronger for them than in those who live in urban area.
认知储备（CR）可以部分解释认知衰退的个体差异。没有研究从生命历程的角度衡量 CR，并调查 CR 与中国老年人大脑认知衰退轨迹之间的关系。
本研究使用了中国健康与退休纵向研究（CHARLS）中 6795 名 60 岁以上的中国成年人的数据。在所有四个波次中都评估了总体认知评分（0-32）。使用儿童时期的环境、教育、最高职业类别和晚年的休闲活动等标志物构建了生命历程 CR 评分。采用潜增长曲线模型（LGCM）评估 CR 与认知衰退轨迹之间的关系。
对于生命历程 CR，成年和晚年的标志物因子负荷大于儿童时期的标志物因子负荷。城市中国成年人的生命历程 CR 评分（范围在-2.727 至 6.537，标准差：1.74）高于农村中国成年人（-0.50，标准差：1.43）。无条件 LGCM 结果表明，城市老年人在基线时的总体认知水平更好（截距：15.010，95%置信区间：14.783，15.237），每年的认知衰退速度也较慢（线性斜率：-0.394，95%置信区间：-0.508，-0.281），低于农村同龄人（截距：12.144，95%置信区间：11.960，12.329；线性斜率：-0.498，95%置信区间：-0.588，-0.408）。在控制了所有协变量后，CR 评分每增加 1 个单位，城市和农村老年人的基线时的总体认知水平分别增加 1.615（95%置信区间：1.521，1.709）和 1.768（95%置信区间：1.659，1.876）个单位。在农村居民中，与较高 CR 相关的认知衰退速度较慢更为明显（斜率：0.083，95%置信区间：0.057，0.108），而在城市居民中则较慢（斜率：0.054，95%置信区间：0.031，0.077）。
CR 与中国老年人的基线认知水平和认知衰退速度较慢有关。尽管农村居民在 CR 和认知方面都处于劣势，但 CR 对认知衰退的保护作用对农村居民的影响要强于城市居民。
