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

UNLABELLED: 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.