AUTHOR=Lin Tian , Liu Gene A. , Perez Eliany , Rainer Robert D. , Febo Marcelo , Cruz-Almeida Yenisel , Ebner Natalie C. TITLE=Systemic Inflammation Mediates Age-Related Cognitive Deficits JOURNAL=Frontiers in Aging Neuroscience VOLUME=10 YEAR=2018 URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2018.00236 DOI=10.3389/fnagi.2018.00236 ISSN=1663-4365 ABSTRACT=

The association between systemic inflammation and cognitive deficits is well-documented. Further, previous studies have shown that systemic inflammation levels increase with age. The present study took a novel approach by examining the extent to which systemic inflammation levels mediated age-related cognitive decline. Forty-seven young and 46 older generally healthy adults completed two cognitive tasks measuring processing speed and short-term memory, respectively. Serum concentrations of three inflammatory biomarkers (including interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP)) were measured in each participant. Both cognitive measures showed age-related deficits. In addition, levels of IL-6 and TNF-α were elevated with age. IL-6 partially mediated the difference in processing speed between the young and the older participant age group; there was no mediation effect for TNF-α and CRP. Considering chronological age, IL-6 partially accounted for age-related impairment in processing speed within older but not young participants. No effects were found for short-term memory. Evidence from this research supports the role of inflammatory processes in age-related cognitive decline. Processes involved in this mediation and differences in inflammatory influence on specific cognitive functions are discussed.