School of Public Health Sciences, Faculty of Health, University of Waterloo, Waterloo, Ontario, Canada.
Gerontology Research Centre, Simon Fraser University, Burnaby, British Columbia, Canada.
J Gerontol A Biol Sci Med Sci. 2023 Feb 24;78(2):314-325. doi: 10.1093/gerona/glac115.
Theoretical perspectives suggest that adiposity and cognitive function may be bidirectionally associated, but this has not been examined in a large-scale data set. The current investigation aims to fill this gap using a large, representative sample of middle-aged and older adults.
Using data from the Canadian Longitudinal Study on Aging (N = 25 854), the bidirectional hypothesis was examined with 3 indicators of cognitive function (ie, executive function, processing speed, and verbal fluency) and adiposity (ie, waist circumference [WC], body mass index [BMI], and total fat mass). We used multivariate multivariable regression and structural equation modeling to assess the prospective associations between adiposity and cognitive indicators.
Analyses revealed that higher baseline WC was associated with higher Stroop interference at follow-up for both middle-aged (standardized estimate, β = 0.08, 95% confidence interval [CI] 0.06, 0.10) and older adults (β = 0.07, 95% CI 0.04, 0.09). Similarly, higher baseline Stroop interference was also associated with higher follow-up WC in middle-aged (β = 0.08, 95% CI 0.06, 0.10) and older adults (β = 0.03, 95% CI 0.01, 0.06). Effects involving semantic fluency and processing speed were less consistent. The earlier effects were similar to those observed using other adiposity indicators (eg, BMI and total fat mass) and were robust to adjustment for demographics and other cofounders, and when using latent variable modeling of the adiposity variable.
Evidence for a bidirectional relationship between adiposity and cognitive function exists, though the associations are most reliable for executive function and primarily evident at midlife.
理论观点表明，肥胖和认知功能可能存在双向关联，但这在大规模数据集上尚未得到检验。本研究旨在使用大量具有代表性的中年和老年人样本填补这一空白。
使用加拿大老龄化纵向研究（N=25854）的数据，使用认知功能的 3 个指标（即执行功能、处理速度和言语流畅性）和肥胖指标（即腰围[WC]、体重指数[BMI]和总脂肪量）来检验双向假说。我们使用多元多变量回归和结构方程模型来评估肥胖与认知指标之间的前瞻性关联。
分析显示，较高的基线 WC 与中年（标准化估计值，β=0.08，95%置信区间[CI]0.06，0.10）和老年（β=0.07，95%CI0.04，0.09）随访时较高的 Stroop 干扰有关。同样，较高的基线 Stroop 干扰也与中年（β=0.08，95%CI0.06，0.10）和老年（β=0.03，95%CI0.01，0.06）随访时较高的 WC 相关。涉及语义流畅性和处理速度的影响不太一致。早期的影响与使用其他肥胖指标（如 BMI 和总脂肪量）观察到的影响相似，并且在调整人口统计学和其他混杂因素以及使用肥胖变量的潜在变量模型时仍然稳健。
肥胖与认知功能之间存在双向关系的证据是存在的，尽管这种关联在执行功能方面最为可靠，主要表现在中年时期。
