Background

Biomarkers for delirium could increase diagnostic accuracy and may help to identify pathological pathways. Until now study findings concerning cytokine levels have been inconsistent.

Aims

Systematic review and meta-analysis investigating the association between peripheral levels of Insulin-like Growth Factor-1 (IGF-1), C-Reactive Protein (C-RP) and Interleukin-6 (IL-6) and delirium in surgical patients, and to explore if there are distinct/specific patterns that may potentially explain inconsistent results.

Methods

PubMed, Scopus, CINAHL, Cochrane, and EMBASE databases were searched. Inclusion criteria were: prospective studies, surgical populations excluding preoperative delirium, available data. The following were collected: type of operation (orthopaedic, abdominal, etc), the timing of operation (acute, elective, both), demographics, number of participants with delirium, time of preoperative blood withdrawal, and preoperative levels of each biomarker.

Results

Low levels of IGF-1 (n = 7 studies) are significantly associated with post-operative delirium in abdominal surgical samples. High levels of C-RP (n = 9) are associated with delirium in acute orthopaedic and elective abdominal operations. IL-6 (n = 14) is a significant predictor of post-operative delirium in a variety of surgical conditions (elective or acute).

Discussion

A common pattern exists in the otherwise conflicting reported findings. This similarity may reflect different underling mechanisms and predisposing factors like cachexia and catabolic stages. It seems that delirium in abdominal surgery is triggered by IGF-1 disturbances, while in other surgeries by an inflammatory reaction.

Conclusions

Despite the contradictory results concerning the association of IGF-1, C-RP and IL-6 with postoperative delirium, the present meta-analysis shows that there are certain patterns. IL-6 seems a consistent predictor for delirium in surgical samples.

中文翻译：

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胰岛素样生长因子 1 (IGF-1)、C-反应蛋白 (C-RP) 和白细胞介素 6 (IL-6) 水平与手术人群谵妄的不一致关联的一致模式。系统评价和荟萃分析

背景

谵妄的生物标志物可以提高诊断准确性，并可能有助于识别病理途径。到目前为止，关于细胞因子水平的研究结果一直不一致。

目标

系统评价和荟萃分析调查外周胰岛素样生长因子-1 (IGF-1)、C-反应蛋白 (C-RP) 和白细胞介素-6 (IL-6) 水平与手术患者谵妄之间的关系，并探索是否存在可能解释不一致结果的不同/特定模式。

方法

检索了 PubMed、Scopus、CINAHL、Cochrane 和 EMBASE 数据库。纳入标准是：前瞻性研究、不包括术前谵妄的手术人群、可用数据。收集了以下内容：手术类型（骨科、腹部等）、手术时间（急性、择期、两者）、人口统计学、谵妄参与者人数、术前抽血时间和术前每种生物标志物的水平。

结果

腹部手术样本中低水平的 IGF-1（n = 7 项研究）与术后谵妄显着相关。高水平的 C-RP (n = 9) 与急性骨科和择期腹部手术中的谵妄有关。IL-6 (n = 14) 是各种手术条件（选择性或急性）中术后谵妄的重要预测因子。

讨论

在其他相互矛盾的报告结果中存在一个共同的模式。这种相似性可能反映了不同的潜在机制和诱发因素，如恶病质和分解代谢阶段。似乎腹部手术中的谵妄是由 IGF-1 紊乱引发的，而在其他手术中则是由炎症反应引发的。

结论

尽管关于 IGF-1、C-RP 和 IL-6 与术后谵妄相关的结果相互矛盾，但目前的荟萃分析表明存在某些模式。IL-6 似乎是手术样本中谵妄的一致预测因子。