Relationship between systemic inflammation and cognitive performance in adolescents with overweight and obesity

Abstract Background/Objective. Excessive body weight has been related to lower cognitive performance. One of the mechanisms through which excess body weight may affect cognition is inflammation. Our study aims at distinguishing between the effects of body mass index (BMI) and those related to systemic inflammation on different aspects of cognition in adolescents with obesity and overweight. Subjects/Methods. One hundred and five adolescents with overweight or obesity between 12 and 21 years participated in the study. Levels of high sensitivity C-reactive protein, interleukin 6, tumour necrosis factors α (TNFα) and fibrinogen were determined from blood samples. Cognitive performance was evaluated, and six cognitive composites were obtained: working memory, cognitive flexibility, inhibitory control, decision-making, verbal memory, and fine motor speed. A single multivariate generalised lineal model was used to assess the influence of the four inflammatory biomarkers, as well as participants’ BMI, sex and age on the 6 cognitive indexes. Results. An inverse relationship between BMI and inhibitory control (F = 5.688, p = .019; β = − .212, p = .031), verbal memory (F = 5.404, p = .022; β = − .255, p = .009) and fine motor speed (F = 9.038, p = .003; β = − .319, p = .001) was observed. Levels of TNFα and fibrinogen were inversely related to inhibitory control (F = 5.055, p = .027; β = − .226, p = .021) and verbal memory (F = 4.732, p = .032; β = − .274, p = .005), respectively. Conclusions. Our data indicate that some components of executive functions, together with verbal memory, are sensitive to specific obesity-related inflammatory agents at early ages.