Abstract: Objective To explore the relationship between serum level of fatty acid binding protein-4(FABP-4) and abdominal aortic calcification(AAC) in patients on peritoneal dialysis(PD).Methods From January 2020 to January 2022,a total of 108 hospitalized PD patients were recruited.There were 58 males and 50 females with an age of(57.2±4.9)(48-72) years.They were divided into two groups of low FABP-4 and high FABP-4 according to the median value of serum FABP-4.Also they were assigned into two groups of no-mild calcification(0-4 points,n=48) and moderate-severe calcification(＞4 points,n=60) according to AAC score.Results There were 54 patients with low FABP-4(＜148.6) and 54 with high FABP-4(4.6,178.9) μg/L.Univariate comparison showed that dialysis time of high FABP-4 group was longer,urea clearance rate was lower,the serum levels of high-sensitivity C-reactive protein(hs-CRP),creatinine,intact parathyroid hormone(iPTH) and alkaline phosphatase(ALP) were higher,body fat mass and percentage were higher and AAC score was higher than low FABP-4 group(P＜0.05).Spearman’s correlation analysis indicated that the level of FABP-4 was correlated positively with dialysis time,hs-CRP,creatinine,iPTH,ALP,body fat percentage and AAC score and negatively with urea clearance(P＜0.05).Multivariate Logistic regression analysis revealed that prolonged dialysis time(OR=1.758,95%CI=1.425-2.231,P＜0.001),higher AAC score(OR=2.302,95%CI=1.859-2.656,P＜0.001) and lower urea clearance(OR=1.542,95%CI=1.236-1.954,P＜0.001) were the independent risk factors for an elevated level of FABP-4.Univariate comparison showed that moderate-severe calcification group had a higher age,more diabetes and cardiovascular diseases,higher serum hs-CRP level,lower albumin level,blood calcium＞2.54 mmol/L and blood phosphorus＞1.45 mmol/L patients increasing,higher body fat percentage increased,greater statin dosing and higher level of serum FABP-4 than no-mild calcification group(P＜0.05).Spearman’s correlation analysis showed that AAC score was correlated positively with age,hs-CRP,blood calcium,blood phosphorus,body fat percentage and FABP-4(P＜0.05).Multivariate Logistic regression analysis indicated that age(OR=1.625,95%CI=1.324-2.012,P＜0.001),hs-CRP(OR=1.859,95%CI=1.526-2.235,P＜0.001),body fat percentage(OR=1.425,95%CI=1.123-1.954,P＜0.001) and FABP-4(OR=2.321,95%CI=2.012-2.654,P＜0.001) were independent risk factors for moderate-severe calcification.The receiver operating curve(ROC) revealed that the area under the curve(AUC) of serum level of FABP-4 for predicting moderate-severe calcification was 0.856 with a cutoff value of 152.3 μg/L,a sensitivity of 85.6% and a specificity of 80.9%.Conclusion Higher serum level of FABP-4 may be closely correlated with the occurrence of moderate-severe AAC in patients on maintenance PD.