Bidirectional Associations Between Adiposity and Cognitive Function: A Prospective Analysis of the Canadian Longitudinal Study on Aging (CLSA)

Abstract

Objectives Theoretical perspectives suggest that adiposity and cognitive function may be bidirectionally associated, but this has not been examined in a large-scale dataset. The current investigation aims to fill this gap using a large, representative sample of middle-aged and older adults. Methods Using data from the Canadian Longitudinal Study on Aging (CLSA; n = 25,854), the bidirectional hypothesis was examined with three indicators of cognitive function (i.e., executive function, processing speed and verbal fluency) and adiposity (i.e., 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. Results 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% 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 above effects were similar to those observed using other adiposity indicators (e.g., BMI, total fat mass) and were robust to adjustment for demographics and other cofounders, and when using latent variable modeling of the adiposity variable. Conclusion Evidence for a bidirectional relationship between adiposity and cognitive function exists, though the associations are most reliable for executive function and primarily evident at mid-life.

Bidirectional Associations Between Adiposity and Cognitive Function and Mediation by Brain Morphology in the ABCD Study

“…For example, it has been reported that children and adolescents with relatively weaker executive control, poorer planning, and more impulsivity at baseline were more likely to have high BMI at follow-up . The hypothesized bidirectional association between adiposity and cognitive function has also been reported in previous studies using adult samples . A recent meta-analysis of longitudinal studies involving children and adolescent samples showed that the existing literature supports a bidirectional relationship between adiposity and executive function .…”

“…[36][37][38][39] The hypothesized bidirectional association adiposity and cognitive function has also been reported in previous studies using adult samples. 7 A recent meta-analysis of longitudinal studies involving children and adolescent samples showed that the existing literature supports a bidirectional relationship between adiposity and executive function. 11 However, it should be noted that meta-analyses included studies that assessed adiposity to executive function or executive function to adiposity associations primarily with a unidirectional assumption, mostly in different studies.…”

“…Obesity is negatively associated with several indicators of cognitive function in adult populations; however, this relationship is less well studied in children and adolescents. A number of studies reported that excess adiposity in childhood is negatively associated with neurocognitive task performance .…”

“…[2][3][4] Overweight children tend to remain overweight throughout their adulthood, and this excess adiposity substantially increases their risk of developing noncommunicable diseases, such as type 2 diabetes, heart diseases, and other chronic conditions at an early age. 2 Obesity is negatively associated with several indicators of cognitive function in adult populations [5][6][7][8] ; however, this relationship is less well studied in children and adolescents. A number of studies reported that excess adiposity in childhood is negatively associated with neurocognitive task performance.…”

Is there a role for higher cognitive processes in the development of obesity in humans?

“…The opposite relationship was also found whereby weight status was associated with poorer executive function, particularly working memory [69]. Bidirectional associations between obesity and cognition have also been reported in a large cohort of adults from the Canadian Longitudinal Study on Ageing [70]. Higher baseline waist circumference was associated with lower executive function at 3-year follow-up for middle aged adults and lower baseline executive function predicted higher waist circumference at follow-up.…”