Association between IL-8 cytokine and cognitive performance in an elderly general population--the MEMO-Study

To investigate the associations between circulating cytokines and specific neuropsychological domains of cognitive functioning (memory, processing speed and motor function) and general cognitive function (MMSE) in healthy elderly individuals.

In a cross-sectional study of 369 community dwelling elderly subjects, we examined the relationship between serum IL-1beta, sIL-4R, IL-6, IL-8, IL-10, IL-12 and TNF-alpha concentrations and cognitive performance using an extensive standardized and validated cognitive test battery assessing memory, word fluency, perceptual/cognitive speed, attention and executive functioning, and motor speed.

Multivariate analysis adjusted for various confounders and Bonferroni correction for multiple comparisons demonstrated that increased serum concentrations of IL-8 were associated with poor performance in the memory and speed domains and in motor function. No significant associations were found between the remaining cytokines and domains of cognitive functioning. Global cognitive functioning, as measured with MMSE, was not associated with any cytokine.

This study suggests an association between circulating IL-8 concentrations and cognitive dysfunction in the elderly. An interaction between this cytokine and glial cells may help explain the pathophysiological mechanisms leading to cognitive impairment in our study group.