Inflammatory markers in postoperative delirium (POD) and cognitive dysfunction (POCD): A meta-analysis of observational studies

• Published in: PloS one Vol. 13; no. 4; p. e0195659
• Main Authors: Liu, Xuling, Yu, Yang, Zhu, Shengmei
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 11.04.2018; Public Library of Science (PLoS)
• Subjects: Alzheimer's disease; Alzheimers disease; Anesthesia; Anesthesiology; Bioindicators; Biology and Life Sciences; Biomarkers; Biomarkers - metabolism; C-reactive protein; Cerebrospinal fluid; Clinical trials; Cognitive ability; Cognitive Dysfunction - metabolism; Cognitive Dysfunction - physiopathology; Confidence intervals; Cytokines; Data processing; Delirium; Delirium - metabolism; Delirium - physiopathology; Heart surgery; Heterogeneity; Humans; Inflammation; Inflammation - metabolism; Interleukin; Interleukin 6; Medicine; Medicine and Health Sciences; Mental disorders; Meta-analysis; Model testing; NMR; Nuclear magnetic resonance; Observational studies; Observational Studies as Topic; Patients; Peptides; Physical Sciences; Postoperative Complications - metabolism; Postoperative Complications - physiopathology; Quality; Regression analysis; Research and Analysis Methods; Sensitivity analysis; Social Sciences; Statistical analysis; Studies; Surgery; Systematic review; China
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0195659

The aim of this study was to summarize and discuss the similarities and differences in inflammatory biomarkers in postoperative delirium (POD) and cognitive dysfunction (POCD). A systematic retrieval of literature up to June 2017 in PubMed, Embase, the Cochrane Library, the China National Knowledge Infrastructure database, and the Wanfang database was conducted. Extracted data were analyzed with STATA (version 14). The standardized mean difference (SMD) and the 95% confidence interval (95% CI) of each indicator were calculated using a random effect model. We also performed tests of heterogeneity, sensitivity analysis, assessments of bias, and meta-regression in this meta-analysis. A total of 54 observational studies were included. By meta-analysis we found significantly increased C-reactive protein (CRP) (9 studies, SMD 0.883, 95% CI 0.130 to 1.637, P = 0.022 in POD; 10 studies, SMD -0.133, 95% CI -0.512 to 0.246, P = 0.429 in POCD) and interleukin (IL)-6 (7 studies, SMD 0.386, 95% CI 0.054 to 0.717, P = 0.022 in POD; 16 studies, SMD 0.089, 95% CI -0.133 to 0.311, P = 0.433 in POCD) concentrations in both POD and POCD patients. We also found that the SMDs of CRP and IL-6 from POCD patients were positively correlated with surgery type in the meta-regression (CRP: Coefficient = 1.555365, P = 0.001, 10 studies; IL-6: Coefficient = -0.6455521, P = 0.086, 16 studies). Available evidence from medium-to-high quality observational studies suggests that POD and POCD are indeed correlated with the concentration of peripheral and cerebrospinal fluid (CSF) inflammatory markers. Some of these markers, such as CRP and IL-6, play roles in both POD and POCD, while others are specific to either one of them.