ObjectiveTo investigate the association between the admission fasting blood glucose-to-albumin ratio (FAR) and short-term prognosis in patients with abdominal aortic aneurysm (AAA) underwent open surgical repair (OSR) or endovascular aneurysm repair (EVAR). MethodsA retrospective study was conducted on patients with AAA who underwent OSR or EVAR at Nanjing Drum Tower Hospital from January 2020 to January 2024 and met the inclusion criteria. The receiver operating characteristic (ROC) curve was used to evaluate the discriminative ability of the FAR for in-hospital mortality after AAA surgery and to determine its optimal cutoff value. Patients were then divided into a low-FAR group (FAR below the cutoff) and a high-FAR group (FAR equal to or above the cutoff) based on this value. Logistic regression analysis, Cox proportional hazards regression models, and Kaplan-Meier survival curves were employed to examine the relation between FAR and postoperative severe complications (Clavien-Dindo grade Ⅲ or above) as well as in-hospital all-cause mortality. ResultsA total of 191 patients were included in this study. The area under the ROC curve of FAR for predicting in-hospital mortality was 0.707 [95%CI (0.637, 0.770)], with an optimal cutoff value of 2.33. There were 164 patients in the low-FAR group and 27 in the high-FAR group. The incidence of postoperative severe complications and in-hospital all-cause mortality were significantly higher in the high-FAR group compared to the low-FAR group [22.22% (6/27) vs. 12.20% (20/164), χ2=5.22, P=0.029; 14.81% (4/27) vs. 2.44% (4/164), χ2=6.03, P=0.014]. An elevated FAR was identified as a risk factor for both postoperative severe complications [OR (95%CI)=1.49 (1.27, 1.88), P=0.018] and in-hospital all-cause mortality [OR (95%CI)=1.35 (1.29, 3.06, P=0.047]. Kaplan-Meier survival analysis showed significantly worse survival in patients with a high-FAR compared to those with a low-FAR (χ2=10.44, P=0.001). ConclusionElevated AAR is a risk factor for poor in-hospital prognosis in AAA patients treated with OSR or EVAR and may serve as a valuable marker for assessing short-term outcomes.