Inflammatory response following heart surgery and association with n À 3 and n À 6 long-chain polyunsaturated fatty acids in plasma and red blood cell membrane lipids L. Bjorgvinsdottir a , O.S. Indridason b , R. Heidarsdottir a , K. Skogstrand c , D.O. Arnar a,b,d , B. Torfason a,e , D.M. Hougaard c , R. Palsson a,b , G.V. Skuladottir a,n a Faculty of Medicine, School of Health Sciences, University of Iceland, Vatnsmyrarvegur 16, IS-101 Reykjavik, Iceland b Internal Medicine Services, Landspitali—The National University Hospital of Iceland, Hringbraut, IS-101 Reykjavik, Iceland c Department of Clinical Biochemistry and Immunology, Statens Serum Institut, Copenhagen, Denmark d Cardiovascular Research Center, Landspitali—The National University Hospital of Iceland, Hringbraut, IS-101 Reykjavik, Iceland e Landspitali—The National University Hospital of Iceland, Hringbraut, IS-101 Reykjavik, Iceland article info Article history: Received 8 April 2013 Received in revised form 12 July 2013 Accepted 26 July 2013 Keywords: Heart surgery Inflammatory mediators Inflammatory response n À3 long-chain polyunsaturated fatty acids Postoperative period Red blood cell membranes abstract Background: Open heart surgery is associated with a systemic inflammatory response. The n À3 long- chain polyunsaturated fatty acids (LC-PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and the n À6 LC-PUFA arachidonic acid (AA) may contribute to modulation of the inflammatory response. Objective: We investigated whether the preoperative levels of EPA, DHA and AA in plasma phospholipids (PL) and red blood cell (RBC) membrane lipids in patients (n ¼168) undergoing open heart surgery were associated with changes in the plasma concentration of selected inflammatory mediators in the immediate postoperative period. Results and conclusions: The postoperative concentration of TNF-β was lower (P o0.05) and those of hs-CRP, IL-6, IL-8, IL-18 and IL-10 higher (P o0.05) than the respective preoperative concentrations. We observed that the preoperative levels of EPA and AA in plasma PL and RBC membrane lipids were associated with changes in the concentration of pro-inflammatory and anti-inflammatory mediators, suggesting a complex role in the postoperative inflammatory process. & 2013 Elsevier Ltd. All rights reserved. 1. Introduction Heart surgery provokes a vigorous inflammatory response that propagates within the injured tissue to initiate the healing process [1–4]. However, excessive systemic inflammation may result in adverse outcomes during the postoperative period [5]. The inflam- matory response is modulated by a balance between pro- inflammatory and anti-inflammatory mediators secreted by a vari- ety of cell types, including activated monocytes, tissue macrophages, lymphocytes and endothelial cells [5–7]. The n À 3 long-chain polyunsaturated fatty acids (LC-PUFA), eico- sapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been shown to evoke anti-inflammatory responses [8], while the n À 6 LC- PUFA aracidonic acid (AA) generally induce a more pronounced pro-inflammatory effect [9, 10]. The fatty acid composition of plasma phospholipids (PL), which are merely transporters of circulating fatty acids, is believed to reflect short-term dietary n À 3 LC-PUFA con- sumption [11]. In contrast, the fatty acid composition of red blood cell (RBC) membrane lipids is considered a good indicator of a long-term dietary n À 3 LC-PUFA consumption [11]. Furthermore, fatty acid composition of RBC membrane lipids has been shown to reflect the fatty acid composition of other cell membrane lipids, including those of cardiac myocytes in the intraventricular septum [12], and atria [13]. Several pro-inflammatory and anti-inflammatory mediators, as well as the acute-phase reactant C-reactive protein (CRP) have been implicated in the inflammatory response early in the post- operative course following open heart surgery [6,7,14–16]. Human studies have demonstrated that dietary EPA and DHA may attenu- ate postoperative concentrations of circulating pro-inflammatory mediators [17,18]. To investigate the role of EPA, DHA and AA in the inflammatory response following open heart surgery, we examined the association between the preoperative levels of EPA, DHA and AA in plasma PL and RBC membrane lipids and the postoperative changes in plasma concentrations of 12 selected inflammatory mediators. Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/plefa Prostaglandins, Leukotrienes and Essential Fatty Acids 0952-3278/$ - see front matter & 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.plefa.2013.07.007 n Correspondence to: Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Iceland, Vatnsmyrarvegur 16, IS-101 Reykjavik, Iceland. Tel.: +354 525 4825; fax: +354 525 4886. E-mail address: gudrunvs@hi.is (G.V. Skuladottir). Prostaglandins, Leukotrienes and Essential Fatty Acids 89 (2013) 189–194