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Rationale and ObjectivesPro-inflammatory processes have been argued to play a role in conditions associated with cognitive decline and neurodegeneration, like aging and obesity. Only a limited number of studies have tried to measure both peripheral and central biomarkers of inflammation and examined their interrelationship. The primary aim of this study was to examine the hypothesis that chronic peripheral inflammation would be associated with neurometabolic changes that indicate neuroinflammation (the combined elevation of myoinositol and choline), brain gray matter volume decrease, and lower cognitive functioning in older adults.Materials and MethodsSeventy-four older adults underwent bio-impedance body composition analysis, cognitive testing with the Montreal Cognitive Assessment (MoCA), blood serum analysis of inflammatory markers interleukin-6 (IL-6) and kynurenine, magnetic resonance imaging (MRI), and proton magnetic resonance spectroscopy (1H-MRS) of the brain. Neurometabolic findings from both Tarquin and LCModel 1H-MRS post-processing software packages were compared. The regions of interest for MRI and 1H-MRS measurements were dorsal posterior cingulate cortex (DPCC), left hippocampal cortex (HPC), left medial temporal cortex (MTC), left primary sensorimotor cortex (SM1), and right dorsolateral prefrontal cortex (DLPFC).ResultsElevated serum kynurenine levels were associated with signs of neuroinflammation, specifically in the DPCC, left SM1 and right DLPFC, and signs of neurodegeneration, specifically in the left HPC, left MTC and left SM1, after adjusting for age, sex and fat percentage (fat%). Elevated serum IL-6 levels were associated with increased Glx levels in left HPC, left MTC, and right DLPFC, after processing the 1H-MRS data with Tarquin. Overall, the agreement between Tarquin and LCModel results was moderate-to-strong for tNAA, tCho, mIns, and tCr, but weak to very weak for Glx. Peripheral inflammatory markers (IL-6 and kynurenine) were not associated with older age, higher fat%, decreased brain gray matter volume loss or decreased cognitive functioning within a cohort of older adults.ConclusionOur results suggest that serum kynurenine may be used as a peripheral inflammatory marker that is associated with neuroinflammation and neurodegeneration, although not linked to cognition. Future studies should consider longitudinal analysis to assess the causal inferences between chronic peripheral and neuroinflammation, brain structural and neurometabolic changes, and cognitive decline in aging.

Many short-term studies with dietary nitrate supplementation in humans and animal models reported positive effects on the cardiovascular system, exercise efficiency, and immune function. However, there has been long-standing concern related to cancer and adverse hormonal effects. We studied the long-term effects of different potassium nitrate (KNO3) concentrations on laboratory mice longevity and structural changes in their organs. Four groups of male mice were treated with 0 mg (0%), 45 mg (1%), 90 mg (2%), and 140 mg (3%) KNO3 in the drinking water. The groups were monitored for agility and health status daily. The lifespan of mice and organ pathological changes were analyzed. We found no detrimental effects of life-long supplementation of KNO3 on the survival of mice in treatment groups. Nitrate supplementation was associated with a lower level of pathological changes (p = 0.002). We conclude that KNO3 supplementation had no carcinogenic effect on mice and possibly prevented the organs from aging.

Purpose: While exercise was found to affect cognitive performance in adolescents, the underlying mechanisms need to be considered. This study compared the effect of a 20 min game-based exercise with different intensities on hormonal responses and potential links to cognitive performance. Methods: 37 adolescents (24 girls and 13 boys; 15–16 years of age) were randomly assigned into light intensity (LIG; 58.64% HRmax), vigorous intensity (VIG; 89.51% HRmax), and control group (CON). The concentration of salivary Testosterone and Cortisol was measured before, immediately after, 20 min and 60 min after the intervention. Results: Repeated-measure ANOVA revealed that neither light nor vigorous game-based exercise acutely affects Testosterone, while Cortisol was higher in the VIG, 20 min after the intervention compared to the LIG and CON. Furthermore, changes in Testosterone were negatively associated with changes in cognitive performance after the acute vigorous intensity exercise (r = −0.63, p = .039) and control condition (r = −0.78, p = .003), but positively associated with post-intervention cognitive performance after the acute light intensity exercise (r = 0.67, p = .012). Conclusion: The intensity of game-based exercise affected Cortisol concentration in adolescents, while Testosterone concentration did not change after the intervention. On the other hand, exercise intensity plays an important role in the association between Testosterone concentration and cognitive performance.