Associations between systemic pro-inflammatory markers, cognitive function and cognitive complaints in a population-based sample of working adults

- Associations between inflammatory cyto-/chemokines & cognitive function were tested in a population-based sample (age 25-67 years).
- Higher MCP-1, IL-6 and CRP were associated with poorer executive functioning.
- Higher MCP-1 was associated with cognitive complaints & episodic memory.
- Age covaried greatly with the associations between cytokines and cognitive variables.
- The association between MCP-1 & executive functioning was robust to extensive adjustments for demographic & health variables.
- Higher cyto-/chemokines were primarily associated with poorer executive functioning in this relatively healthy sample.

BackgroundThe knowledge is limited regarding the relation between systemic inflammatory biomarkers and subjective and objective cognitive functioning in population-based samples of healthy adults across the adult age-span. Thus, the aim of this study was to study a selection of four pro-inflammatory biomarkers (IL-6, MCP-1, TNF-α, CRP) in relation to executive cognitive functioning, episodic memory and subjective cognitive complaints (SCC) in a population-based sample of 215 working adults (age 25-67).ResultsHigher levels of MCP-1 were associated with poorer executive cognitive functioning, even after adjustments for demographical factors, health status/conditions, SCC and depressive symptoms. IL-6 and CRP were associated with poorer executive cognitive functioning, but these associations covaried with age especially and were not present after adjustment for demographical factors.MCP-1 was associated with poorer episodic memory, but this association also covaried with age especially and was not present after adjustment for demographical factors, and CRP was associated with episodic memory only among participants without reported health conditions. Higher MCP-1 levels were also associated with more SCC and this association covaried with depressive symptoms, while higher levels of TNF-α were associated with less SCC.ConclusionLow grade inflammatory processes in terms of higher systemic levels of pro-inflammatory biomarkers (MCP-1, IL-6 & CRP) were associated with poorer executive functioning in this sample of working adults, and MCP-1 was so after extensive adjustments. Support for associations between these biomarkers and episodic memory and SCC were more limited. Future research should address the causality of associations between low grade inflammatory processes and cognitive functioning.