Evaluation of the relationship between mild cognitive impairment and CRP/Albumin ratio in the geriatric population

Mild Cognitive Impairment (MCI) represents an intermediate stage between normal aging and dementia. Systemic inflammation has been increasingly investigated in relation to age-related cognitive decline. The C-reactive protein/albumin ratio (CAR) is a novel inflammatory marker, yet its association with MCI in older adults remains uncertain. This single-center, cross-sectional study included 300 participants aged ≥ 65 years evaluated at the Healthy Aging Center and Neurology Outpatient Clinic. Individuals with acute infection, systemic inflammatory disease, malignancy, immune deficiency, recent trauma, end-stage organ failure, or major psychiatric/neurological disorders were excluded. Cognitive status was assessed using the Montreal Cognitive Assessment (MoCA). Laboratory parameters included CRP, albumin, glucose, hemoglobin, and complete blood count. CAR was calculated as (CRP/albumin × 100). Group comparisons, Spearman correlations, and univariable and multivariable logistic regression analyses were performed. Of the participants, 204 (68.0%) had MCI. CAR levels were significantly higher in the MCI group (median 34.9 vs. 19.5; p < 0.001), while albumin and glucose levels were lower ( p < 0.05). CAR showed the strongest correlation with MoCA score ( r = − 0.40, p < 0.001). In logistic regression, CAR was independently associated with MCI (OR = 1.035, 95% CI: 1.019–1.053), whereas albumin and glucose demonstrated inverse associations. The explanatory power of the final model was modest (Nagelkerke R² = 0.307). CAR was significantly associated with MCI in older adults, suggesting a potential link between systemic inflammation and cognitive performance. However, due to the cross-sectional design and modest model explanatory power, CAR should not be interpreted as a causal or standalone diagnostic marker. Longitudinal and multicenter studies are needed to evaluate whether inflammatory profiles including CAR are related to cognitive trajectories over time. Not applicable.