The Relationship between Serum SAA/CRP Ratio and Pulmonary Infection in Elderly Patients with Alzheimer's Disease Hospitalized
YANG Xiaoyan
WU Guolin
TU Zunkui
ZHANG Ying
XIANG Min
WU Yafeng
Abstract：Objective To explore the relationship between serum amyloid A/C-reactive protein(SAA/CRP)ratio and pulmonary infection in elderly hospitalized patients with Alzheimer's disease(AD).Methods A total of 120 elderly AD inpa-tients from the Fourth People's Hospital of Ya'an City from April 2023 to March 2025 were selected as the research subjects,including 38 patients with pulmonary infections during hospitalization(infection group)and 82 patients without pulmonary infections(non-infection group).Serum SAA and CRP levels were measured and the SAA/CRP ratio was calculated for both groups.Receiver operating characteristic(ROC)curve and the area under the curve(AUC)were used to analyze the assessment value of each index for pulmonary infection in elderly AD inpatients.Binary logistic stepwise regression analysis was employed to identify influencing factors for pulmonary infection in elderly AD inpatients.Results SAA,CRP levels,and the SAA/CRP ratio were higher in the infection group than in the non-infection group(P<0.05).The AUC(95%CI)for SAA,CRP,and the SAA/CRP ratio in evaluating pulmonary infection in elderly AD patients were 0.828(0.783-0.878),0.773(0.728-0.823),and 0.906(0.861-0.956),respectively.The AUC of the SAA/CRP ratio assessment was higher than that of SAA and CRP evaluation alone(Z=9.301,P<0.001;Z=12.257,P<0.001).The proportion of patients with age≥75 years,diabetes,smoking history,long-term immobilization,eating difficulties,and modified plaque index(mPLI)≥2 was higher in the infection group than in the non-infection group(P<0.05).Binary logistic stepwise regression analysis showed that long-term immobiliza-tion(OR=2.094,95%CI:1.088-4.029),diabetes(OR=2.192,95%CI:1.153-4.170),mPLI≥2(OR=2.270,95%CI:1.239-4.161),and SAA/CRP ratio(OR=3.714,95%CI:2.055-6.712)were independent influencing factors of pulmonary infection in elderly AD inpatients(P<0.05).Conclusion The elevated serum SAA/CRP ratio is closely associated with the risk of pul-monary infection in elderly hospitalized AD patients,and is expected to provide important evidence for clinical identification of high-risk populations and optimization of intervention strategies.
Keywords：Alzheimer's diseaseElderlyPulmonary infectionAmyloid AC-reactive proteinEvaluate valueInflu-encing factors
Publication Date：2025-07-20
Online Publishing Date：2025-08-27(First online date of this platform, not the publication date of the document)
Pages：5( 13-17 )