Background: Both ghrelin and leptin are important signals in the regulation of food intake and energy balance. Leptin concentrations are elevated in the majority of obese individuals, and its levels usually correlate with adiposity and body mass index. Ghrelin as a new growth hormone (GH)-releasing peptide was discovered in 1999. Ghrelin stimulates food intake and exhibits gastroprotective properties. Many other regulatory effects of both ghrelin and leptin involving cardiovascular, gastrointestinal, renal, and endocrine systems were revealed. New experimental studies show both hormones as new acute phase reactants in animal models of inflammatory reaction. The aim of this study was to characterize the levels of circulating ghrelin and leptin in relation to systemic inflammatory response. We used a postoperative bacterial sepsis after large abdominal surgery as a model of cytokine network hyperstimulation. Patients and Methods:The prospective study was performed on 25 surgical patients with proven postoperative intra-abdominal sepsis after large abdominal surgery. Plasma levels of ghrelin (RIA), leptin, TNF-α, IL-1β, sIL-2R, IL-6 (ELISA analysis), CRP and α₁-antitrypsin (nephelometric analysis) were analyzed. Results: Authors demonstrate statistically significant elevation of plasma ghrelin (492.3 ± 70.6 ng/l) and leptin (31.6 ± 12.2 µg/l) compared with the control group (336.5 ± 46,1, p < 0.01 for ghrelin, 3.5 ± 1.2 µg/l, p < 0.001 for leptin). The regression coefficient was the highest for ghrelin and IL-6 (r = 0,44, p < 0.05), and for ghrelin and TNF (r = 0.43, p < 0.05) in the sepsis group. In regard to leptin, the regression coefficient was the highest for IL-6 and leptin (r = 0.53, p < 0.05) and for leptin and CRP (r = 0.51, p < 0.05). There was no significant correlation between ghrelin and IL-1β, ghrelin and sIL-2R, and leptin and IL-1β. Conclusions: During postoperative intra-abdominal sepsis, both ghrelin and leptin plasma levels are elevated and positively correlate with both inflammatory cytokines (TNF-α, IL-6) and main APP member (CRP). It supports experimental finding that TNF-α and IL-6 can be important regulatory factors of their synthesis. This hormonal reaction is not specific to sepsis – the significant increase of both ghrelin and leptin occurs during an uncomplicated postoperative response, although in a lesser extent than was shown in sepsis.

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Ghrelin is a novel peptide hormone which was identified as an endogenous growth hormone secretagogue. It is mainly secreted in the stomach, but important sites of its secretion are other parts of the gastrointestinal tract. Ghrelin is thought to be involved not only in regulation of growth hormone secretion but also in regulation of food intake and nutritional status. This study was aimed to investigate the changes in plasma ghrelin levels in patients with short bowel syndrome. Twenty-four patients with malnutrition due to short bowel syndrome and eleven healthy controls were included in the study. They underwent clinical examination and assessment of plasma or serum levels of ghrelin leptin, soluble leptin receptor, IGF-I, IGFBP-1 and IGFBP-3. Plasma ghrelin levels were decreased in patients with short bowel syndrome (p<0.01). Furthermore, decreased serum levels of IGF-I (p<0.01) and IGFBP-3 (p<0.001) were found in patients with short bowel syndrome. Other laboratory differences between both groups were not significant. No relationship between ghrelin and other determined variables was found. We conclude that plasma ghrelin levels are decreased in the group of patients with short bowel syndrome. It is probably because of a decrease in the tissue mass that is able to secrete ghrelin.

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-alpha (TNF-alpha), interleukin-1beta, IL-6, IL-8, soluble IL-2 receptor, C reactive protein, and alpha1-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-alpha 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-1beta 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.

Ghrelin is a peptide hormone that is involved in regulating growth hormone secretion as well as food intake and energy homeostasis. The aim of this study was to compare changes in plasma ghrelin levels in patients with malnutrition due to anorexia nervosa (AN) or short bowel syndrome (SBS). Blood samples for laboratory analyses were taken from 16 AN patients (plus 13 comparable healthy controls) and 27 SBS patients (plus 13 comparable healthy controls) after an overnight fast. In comparison with their respective control groups, plasma ghrelin levels were increased in the AN patients (p < 0.05) and significantly decreased in the patients with SBS (p < 0.01). These results suggest that quantitative ghrelin secretion in the gut wall is important in determining ghrelin concentrations in the systemic circulation.