The relationship between chronic inflammatory disease and cognitive decline is still unclear, but there is increasing evidence to support the role of systemic inflammation. The aim of this study was to investigate if chronic rhinosinusitis (CRS) in dementia or mild cognitive impairment (MCI) is associated with the progression of cognitive decline.

We retrospectively reviewed the data of patients who complained of memory impairment, and underwent brain magnetic resonance imaging (MRI) from January 2006 to April 2019. According to the Mini-Mental State Examination (MMSE) score, subjects (n=661) were divided into three groups: dementia (≤17), MCI (18–23), and normal (≥24). CRS was defined as a total score of greater than or equal to 4 according to the Lund–Mackay scoring system using brain MRI. Multiple logistic regression analyses estimated adjusted odds ratio (aOR) for the association between CRS and dementia or MCI. Among the subjects with follow-up MMSE (n=286), a repeated-measures ANOVA was used to assess the difference of changes in MMSE scores between the groups with and without CRS.

According to the initial MMSE score, there were 221 subjects with dementia, 195 with MCI, and 245 with normal results. CRS was not significantly associated with dementia (aOR=1.519, CI=0.909–2.538, P=0.111), while being suggestively associated with MCI (aOR=1.740, CI=1.041–2.906, P=0.034). The MMSE scores at follow-up decreased further in subjects with CRS than in those without CRS (P=0.009). Especially, in the initial dementia group, there was a significant between-group difference in the MMSE score from baseline to follow-up (13.6±4.3 to 11.1±6.3 in CRS group vs. 13.5±3.3 to 14.4±5.4 in no CRS group, P=0.002).

The result of the present study implies a potential association between CRS and progression of cognitive decline. Physicians should be aware of this possibility in patients with clinically diagnosed CRS.