Correlations of Epigenetic Changes With POCD in Surgical Patients

Study Overview
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Brief Summary
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Postoperative cognitive dysfunction (POCD) is a subtle cognitive dysfunction, especially postoperative memory impairment lasting for weeks or months. The underlying pathophysiological mechanism of POCD remain unclear. The aim of this study is to explore the epigenetic changes during perioperative period and its correlation with POCD in surgical patients.

Detailed Description
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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.

Official Title
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Correlations of Epigenetic Changes With POCD in Surgical Patients

Conditions
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Postoperative Cognitive Dysfunction

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: •ASA Grade I to III Age >65 BMI 18-28kg/m2 Patients undergoing abdominal surgery,orthopedic surgery and spinal surgery Exclusion Criteria: Exclusion Criteria: do not consent, Patients with mini mental state examination (MMSE)score of ≤20 at screening severe heart,kidney or lung disfunction;unstable angina undergoing abdominal operation previously refuse to use PCA unexpected surgical complication such as bleeding; psychiatric disorders; drug or alcohol abuse

Ages Eligible for Study
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Minimum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| non-POCD<br>Patients who don't develop POCD after surgery. | |
| POCD<br>Patients who develop POCD after surgery. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation of epigenetic changes with POCD | The present study will examine concentration of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) in whole blood by enzyme-linked immunosorbent assays (ELISA) to determine the correlation of epigenetic changes with POCD in surgical patients. | 24 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The effects of surgical and anesthesia stress on epigenetic changes | Numerous studies have reported that both acute and chronic stress can cause epigenetic modification. Surgical stress also belongs to acute stress during perioperative period. Thus the present study will compare concentration of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) before and after operation to determine whether surgical and anesthesia stress will induce epigenetic changes. | 24 hours |