Elevated C-Reactive Protein Is Associated with Cognitive Decline in Outpatients of a General Hospital: The Project in Sado for Total Health (PROST)

BACKGROUND/AIMS: We aimed to determine whether the concentration of serum C-reactive protein (CRP) is associated with cognitive function in an adult Japanese population. METHODS: Participants of this cross-sectional study were from a subgroup of the Project in Sado for Total Health (PROST; n = 454; mean age, 70.5 years). The cognitive state was evaluated using the Mini-Mental State Examination (MMSE), and those with an MMSE score <24 were considered ‘cognitively declined’. Concentrations of serum high-sensitivity CRP were measured. Multiple logistic regression analysis was used to calculate odds ratios (ORs) for cognitive decline, adjusting for the covariates of age, sex, BMI, disease history, and APOE allele. RESULTS: Of the 454 participants, 94 (20.7%) were cognitively declined. Relative to the lowest (first) quartile of CRP concentration, adjusted ORs were 1.29 (95% CI 0.61-2.75) for the second, 1.78 (95% CI 0.82-3.86) for the third, and 3.05 (95% CI 1.45-6.42) for the highest (fourth) quartiles (p for trend = 0.018). When data were stratified by sex, the association between CRP concentration and cognitive decline was observed only in women. CONCLUSION: Our findings suggest an association between higher CRP concentration and lower cognitive function. Chronic inflammation may affect cognitive function in adults, in particular women.