Inflammation Mediates Body Weight and Ageing Effects on Psychomotor Slowing

Abstract

Inflammation (immune system activation) affects neuronal function and may have consequences for the efficiency and speed of functional brain processes. Indeed, unusually slow psychomotor speed, a measure predictive of behavioural performance and health outcomes, is found with obesity and ageing, two conditions also associated with chronic inflammation. Yet whether inflammation is the mediating factor remains unclear. Here, we assessed inflammation by indexing interleukin-6 level in blood and measured psychomotor speed as well as indices of selective visual attention in young (mean = 26 years) or old (mean = 71 years) adults (N = 83) who were either lean or currently significantly overweight (mean body mass index = 22.4 and 33.8, respectively). Inflammation was positively and significantly correlated with psychomotor speed, age, and body mass index but not with attention measures. Using mediation analyses we show for the first time that inflammation fully accounts for the significant psychomotor slowing found in those with high BMI. Moreover, we further show that age-related psychomotor slowing is partially mediated by inflammation. These findings support the proposal that reducing inflammation may mitigate weight- and age-related cognitive decline and thereby improve performance on daily tasks and health outcomes more generally.

Proteomic Profiling of Extracellular Vesicles Separated from Plasma of Former National Football League Players at Risk for Chronic Traumatic Encephalopathy

“…Indeed, we observed significant negative correlation between BMI and Psychomotor speed/ Executive Function values when both CTRL and NFL players are combined, although there was no correlation when two groups are separately analyzed, which is a potential confounding factor in this study. Aging is also a confounding factor of psychomotor speed / executive Function [ 54 ]. However, there was no correlation between age and Psychomotor speed / Executive Function values in this study.…”

Longitudinal Body Weight Change, Visit-To-Visit Body Weight Fluctuation, and Cognitive Decline Among Older Adults

“…We also used an alternative approach, i.e., mixed-effect model to estimate body weight change and body weight fluctuation. As inflammation related mechanisms have been suggested to link body weight to cognitive decline [29,30], we further adjusted for the use of anti-inflammatory medications in the analyses.…”

Acute Diesel Exhaust Exposure Causes a Delayed Reduction in Cognitive Control

“…A candidate process to explain the delayed effect is an inflammatory response that results in modulated neurotransmission. Short-term air pollution exposure has been shown to cause a neuroinflammatory response [40,41,42,43] , and vaccination paradigms show that neuroinflammation negatively impacts attentional processing and therefore, potentially, cognitive control, about 6 hours after vaccination [34,35] . These findings are consistent with the speculation that inflammatory responses to AAP led to the observed cognitive deficits in our DE-d group.…”

“…Neuroinflammation, without a specific AAP association, has been linked to both psychomotor slowing [33,34] and higherorder cognitive consequences, including degradation of attention and social-emotional perception [35,36,37,38] . Critically, these consequences are measurable even with very mild inflammation that does not provoke classic signs of sickness behaviour such as fever and social withdrawal [34,36,37] . This raises the possibility that acute exposure to AAP, also not typically associated with sickness behaviour, could nevertheless produce similarly negative effects on cognition.…”