Assessment of Sleep, Cognitive Performance, and Circulating Cytokines in Adults with Chronic Rhinosinusitis

Background/Objectives: Chronic rhinosinusitis (CRS) is commonly accompanied by sleep disturbance and cognitive complaints, but the relationships among CRS, cognition, subjective sleep, and circulating inflammatory cytokines remain incompletely understood. Methods: In this case-control study, 80 adults with CRS and 98 controls completed validated sleep and sinonasal questionnaires and a 12-test cognitive battery assessing six domains. Plasma cytokines were measured in 101 participants with available biospecimens. Multivariable linear regression and exploratory correlation analyses were performed with false discovery rate correction. Results: Adjusted cognitive domain scores did not differ between CRS and controls. In age-by-group interaction models, CRS showed a nominally steeper age-associated decrease in episodic memory (β = -0.12, 95% CI -0.21 to -0.03; p = 0.009; q = 0.053), with weaker nominal patterns for working memory (β = -0.10, 95% CI -0.20 to -0.003; p = 0.044; q = 0.096) and visuospatial ability (β = -0.08, 95% CI -0.15 to -0.001; p = 0.048; q = 0.096). Plasma IL-6 was nominally higher in CRS after adjustment (β = 0.36, 95% CI 0.04 to 0.67; p = 0.026; q = 0.18) but did not remain significant after cytokine-level correction. Within CRS, exploratory analyses showed nominal inverse correlations between IL-6 and visuospatial ability (ρ = -0.36; p = 0.008; q = 0.236), as well as a nominal positive correlation between IL-13 and semantic memory (ρ = 0.33; p = 0.020; q = 0.236); however, none survived correction for multiple comparisons. Conclusions: Adults with CRS reported greater sleep-related burden and showed a nominally steeper age-related decrease in episodic memory. IL-6 and IL-13 showed nominal cognitive associations that did not survive correction, supporting the need for larger longitudinal studies to clarify clinical relevance.