School of Health and Wellbeing, University of Glasgow, Glasgow, UK.
NHS Lanarkshire Neuropsychology Service, Monklands Hospital, Airdrie, UK.
Int J Epidemiol. 2023 Oct 5;52(5):1592-1611. doi: 10.1093/ije/dyad009.
Physical activity (PA) has been associated with benefits for cognitive function (CF), but previous estimates of the strength of this relationship may have been biased due to limitations in statistical modelling practices that are common among observational studies. We aimed to address this by using a rigorously constructed conceptual causal model to guide an empirical analysis estimating the effect of PA on CF in the UK Biobank cohort of middle-aged and older adults.
This study analysed a subsample of 334 227 adults from the UK Biobank prospective cohort study. PA was measured subjectively by self-report and by device using accelerometry, and CF was measured using objective cognitive tests. Composite CF measures were derived to represent general and domain-specific performance. Effect coefficients were estimated using regression models, adjusting for a wide range of confounders specified by the assumed causal model, including genetic risk factors, and relevant health, sociodemographic and behavioural variables from across the lifespan.
Results indicated very small effect sizes (standardized mean difference estimates all <0.01) of inconsistent direction, for both cross-sectional and longitudinal analyses.
The expected protective effect of PA on CF was not observed. This may reflect selection bias within UK Biobank, or the relatively young age of the sample at follow-up.
身体活动（PA）与认知功能（CF）的益处有关，但由于观察性研究中常见的统计建模实践的局限性，之前对这种关系强度的估计可能存在偏差。我们旨在通过使用严格构建的概念因果模型来解决这个问题，该模型指导对英国生物库中年和老年人队列中 PA 对 CF 的影响进行实证分析。
本研究分析了来自英国生物库前瞻性队列研究的 334227 名成年人的一个子样本。PA 通过自我报告和使用加速度计的设备进行主观测量，CF 通过客观认知测试进行测量。复合 CF 测量值用于表示一般和特定领域的表现。使用回归模型估计效应系数，调整了因果模型中规定的广泛混杂因素，包括遗传风险因素以及来自整个生命周期的相关健康、社会人口统计学和行为变量。
结果表明，无论是横断面分析还是纵向分析，效应大小都非常小（标准化均差估计值均<0.01），且方向不一致。
未观察到 PA 对 CF 的预期保护作用。这可能反映了英国生物库中的选择偏差，或随访时样本相对年轻。
