No Influence of Surgical Stress on Postoperative Leptin Gene Expression in Different Adipose Tissues and Soluble Leptin Receptor Plasma Levels

As part of the postsurgical stress response, plasma leptin levels increase in-between 12 h postoperatively. Objective: To study the kinetics of leptin gene expression in different adipose tissues before and after severe surgical trauma in children and adults. Methods: In 22 adults and 23 children with cardiac and 19 adult patients with abdominal surgery, we measured plasma leptin concentrations preoperatively, 4 and 10–17 h postoperatively and quantified leptin mRNA expression by TaqMan real-time PCR in adipose tissue taken at the beginning and the end of surgery from subcutaneous, intrathoracic, omental and mesenteric fat. Plasma-soluble leptin receptor levels were measured in 23 children after cardiosurgery. Results: Plasma leptin levels doubled between 4 and 10–17 h postoperatively in adults (p < 0.001) as well as in children (p = 0.0002) with cardiac surgery. After abdominal surgery, 10–17 h postoperatively, plasma leptin concentrations increased significantly (p < 0.05). During the operation, leptin gene expression did not change in neither of the patient groups. Plasma-soluble leptin receptor levels decreased immediately after the onset of surgery and remained unchanged thereafter. Conclusions: Leptin gene expression is not up-regulated during surgery. The measured increase in plasma leptin after surgery does not result from elevated levels of soluble leptin receptor but may follow an up-regulation of leptin gene expression later after the operation due to postsurgical metabolic changes.