Inflammatory biomarkers are associated with spatial navigation in older adults

OBJECTIVES: Spatial navigation is a complex cognitive skill that is important for daily functioning. Declines in navigation ability have been frequently noted in people with cognitive impairment. While previous research has linked inflammation to spatial navigation in animal models, the effects in humans, and specifically older adults, remain unknown. We aimed to assess the relationship between inflammatory biomarkers and spatial navigation ability. METHODS: We examined the association between levels of interleukin-6 (IL-6) and C-Reactive protein (CRP) and time taken to complete the Floor Maze Test (FMT) using multiple regression models in 206 community-dwelling older adults (M age 78.3 ± 6.7 years, 53% female). We calculated beta coefficients with 95% confidence intervals (CI) for the overall sample, as well as stratified by sex. RESULTS: Performance on the immediate FMT was significantly associated with CRP, after adjusting for demographics, mobility, and physical health, and episodic memory and executive function (Beta = 1.18, 95% CI: 1.04-1.35, p = 0.01). Our stratified analysis indicated that this effect may be sex-specific and present only in female participants. We did not find any significant associations with the delayed FMT in men or with IL-6. DISCUSSION: Higher levels of CRP are associated with worse spatial navigation performance, particularly in female older adults. Though this study is cross-sectional, it highlights the effects of inflammation on an important cognitive skill, spatial navigation.