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DOI: 10.1055/s-2008-1065329
© Georg Thieme Verlag KG Stuttgart · New York
Ghrelin as an Acute-phase Reactant during Postoperative Stress Response
Publication History
received 30.04.2007
accepted after second revision 13.12.2007
Publication Date:
10 April 2008 (online)


Abstract
Ghrelin is a growth hormone-releasing peptide, discovered in 1999 by Kojima et al. Its potential role in inflammation and stress response is not yet clear. The purpose of this study was to characterize perioperative levels of circulating ghrelin in relation to different surgical procedures. The authors compared plasma ghrelin changes with cortisol, cytokines, and acute-phase proteins. The prospective study was performed on 22 patients with resection for colon cancer (group 1). Group 2, functioning as a comparative group, consisted of 22 patients with elective laparotomic cholecystectomy. Plasma concentrations of ghrelin, cortisol, tumor necrosis factor-α (TNF-α), interleukin-1β, IL-6, IL-8, soluble IL-2 receptor, C reactive protein, and α1-antitrypsin were estimated repeatedly during a 72-hour postoperative period. Data revealed significant elevation of plasma ghrelin 24 hours after resection of coli (median 508.0 ng/l, interquartile range 398.2-633.7 ng/l) in relation to both preoperative levels (317.6 ng/l, 253.4-355.1 ng/l, p<0.01) and group 2 maximal postoperative levels (386.2 ng/l, 324-432 ng/l, p<0.05). Ghrelin levels returned to initial status 36-48 hours after surgery with subsequent decline to subnormal levels. The regression coefficient was the highest for ghrelin and TNF-α 24 hours after laparotomy (r=0.64, p<0.05) and for ghrelin and IL-6 24 hours after surgery (r=0.56, p<0.05). Maximal postoperative levels of all tested parameters except for cortisol and IL-1β differed significantly between both patient groups at p<0.05. After large abdominal surgery, ghrelin shows itself as an acute-phase reactant. The significant correlation between ghrelin and inflammatory cytokines supposes their regulatory role in this period. Our comparison of more- and less-invasive surgical procedures with similar nutritional restrictions argues for a dominant role of inflammatory factors in postoperative ghrelin elevation.
Key words
acute phase response - C reactive protein - interleukin-6 - surgery - tumor necrosis factor