Correlations of Epigenetic Changes With POCD in Surgical Patients

The incidence of postoperative cognitive dysfunction (POCD) in elderly patients ranges widely from 16% to 21% and is associated with adverse outcomes. The exact cause of POCD remains unknown. Extensive studies report that epigenetic modification, including the alteration of DNA methylation and chromatin structure, plays an important part in the regulation of memory and learning. The present study thus hypothesize that epigenetic modification may increase the risk for POCD. The present study will enrolled the elderly patients (aged≥65) and young and middle-aged patents (aged 20-50) who are planning to undergo elective noncardiac surgery under general anesthesia. Perioperative clinical characteristics of all patients will be recorded. Participants enrolled will be evaluated for POCD with Mini-Mental State Examination (MMSE) on preoperative day, postoperative days 1. Postoperative pain will be evaluated by the numerical rating scale (NRS). The patients' blood will be collected in the morning on the day before surgery and after surgery when they recover consciousness for the detection of concentration of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) by enzyme-linked immunosorbent assays (ELISA).

The present study may help to find whether epigenetic changes will occur after surgical and anesthesia stress and will be an important factor for POCD in elderly patients.