Serum High-mobility Group Box1Protein Correlates With Cognitive Decline After Gastrointestinal Surgery

Objective:To investigate the perioperative change of serum HMGB1levels in patients undergoing major gastrointestinal surgery and to determine the relationship between HMGB1and postoperative cognitive dysfunction in elderly.Methods:Fifty-three elderly patients undergoing gastrointestinal surgery were recruited into this prospective study. Serum HMGB1and IL-6levels were measured preoperatively and at6h, day1and day3postoperatively. Neuropsychological tests were administered before and1week after surgery. POCD was determined using a Z score≥1.96recommended by International Study Of Postoperative Cognitive Dysfunction (ISPOCD) group.Results:1.50patients completed the study, of whom seventeen (34%,17/50) developed POCD at1week after surgery.2. There were no significant differences regarding demographics and peri-operative clinical features between groups with and without POCD (P>0.05).3. A comparison of heart rates and mean arterial pressure values within or between the two groups revealed no significant differences (P>0.05).4. The results of preoperative cognitive tests were comparable between the two groups (P>0.05). The postoperative performance of neuropsychological testing including BVMT-R Recognition Discriminating Index and Verbal Fluency Test showed significant deterioration (P<0.05) compared with baseline scores in both groups.5. HMGB1serum levels at each postoperative time point were significantly higher than baseline value in both POCD group and No POCD group (P<0.001). The peak level occurred on postoperative day1. There was a significant difference between the two groups on day1or day3after surgery (P=0.021, P=0.011, respectively). In both groups, serum IL-6levels at6h, day1and day3after surgery were larger than those at baseline (P<0.001). Patients who exhibited cognitive dysfunction had higher IL-6levels at6h and day1postoperatively compared to those who did not (P=0.009, P=0.026, respectively).6. Spearman correlation analyses indicate that HMGB1levels at day1(r=0.33, P=0.0197) or day3(r=0.34, P=0.0158), IL-6at6h (r=0.39, P=0.0054) showed a strong positive correlation with the composite Z score.7. Multiple linear regression analyses demonstrate that IL-6levels at6h, HMGB1levels at day1and years of education had significant influence on composite Z scores and all showed a positive correlation with Z scores.Conclusions:Serum HMGB1and IL-6levels increase significantly after major gastrointestinal surgery in elderly patients and such elevations are associated with the occurrence of cognitive decline after surgery.