###### Abstract  
This study aimed to explore the role of preoperative and postoperative C-reactive protein (CRP) levels in mediating the association between the preoperative depression symptoms and postoperative length of stay in patients undergoing coronary artery bypass grafting (CABG). Preoperative depression symptoms of 212 elective CABG patients were measured using the Beck Depression Inventory (BDI-II). The patient's demographic and clinical parameters were collected from medical records prior to surgery. Patients were followed up during their in-hospital stay to measure early (1-3 days post-surgery) and persistent (4-6 days post-surgery) CRP response to CABG surgery. The higher persistent CRP response was significantly (\(p<0.001\)) associated with a longer postoperative hospital stay. The binary logistic regression analysis confirmed the association of persistent CRP change with prolonged hospital stay (OR = 1.017, 95% CI = 1.005-1.029, \(p=0.009\)). However, when the gender subgroups were analyzed separately, that remained significant (OR = 1.016, 95% CI = 1.004-1.028, \(p=0.005\)) only for the male subgroup. There was no significant association between elevated BDI-II depression scores and longer postoperative hospital stay. Additionally, no significant influence of BDI-II scores on preoperative or postoperative CRP levels, or vice versa, was detected. Further work is needed to explore the extent and pathways through which depression might influence the postoperative recovery of CABG patients. c 2022 by the authors. Liconse MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ([[https://creativecommons.org/licenses/py/4.0/](https://creativecommons.org/licenses/py/4.0/)]([https://creativecommons.org/licenses/py/4.0/](https://creativecommons.org/licenses/py/4.0/))). 1  
The Association of Preoperative Depression, and C-Reactive Protein Levels with a Postoperative Length of Stay in Patients Undergoing  
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The patient's demographic and clinical parameters were collected from medical records prior to surgery. Patients were followed up during their in-hospital stay to measure early (1-3 days post-surgery) and persistent (4-6 days post-surgery) CRP response to CABG surgery. The higher persistent CRP response was significantly (\(p<0.001\)) associated with a longer postoperative hospital stay. The binary logistic regression analysis confirmed the association of persistent CRP change with prolonged hospital stay (OR = 1.017, 95% CI = 1.005-1.029, \(p=0.009\)). However, when the gender subgroups were analyzed separately, that remained significant (OR = 1.016, 95% CI = 1.004-1.028, \(p=0.005\)) only for the male subgroup. There was no significant association between elevated BDI-II depression scores and longer postoperative hospital stay. Additionally, no significant influence of BDI-II scores on preoperative or postoperative CRP levels, or vice versa, was detected. Further work is needed to explore the extent and pathways through which depression might influence the postoperative recovery of CABG patients. 20221212021202120212120  
blood cholesterol levels, diabetes, hypertension, family history, and race [3; 4]. In addition, the patient's psychological state in terms of depression, anxiety, anger, and stress has also been implicated as potential risk factor in the development of an increased incidence of morbidity and mortality of CAD patients [5; 6; 7; 8]. Depression is highly prevalent (17% to 27%) in CAD patients, including those with stable CAD, unstable angina, or myocardial infarction [9]. The prevalence of significant depressive symptoms is diagnosed in more than 20% of CAD patients, while many have subsyndromal depressive symptoms below the diagnostic threshold [7; 9; 10]. Therefore, depressive symptoms are frequently underdiagnosed and consequently left untreated in CAD patients, although they may exist for a long time before the onset of disease [10; 11].