The Effect of Myopenia on the Inflammatory Response Early after Colorectal Surgery.

Background: Myopenia (low skeletal muscle mass) is associated with an increased risk of complications following colorectal surgery, however, the underlying mechanism is poorly understood. This study investigates the effect of myopenia on the early postoperative systemic inflammatory response. Materials and methods: In 78 patients undergoing colorectal surgery, the presence of myopenia was preoperatively assessed using computed tomography images of the third lumbar vertebra. Interleukin-8 (IL-8) and soluble tumor necrosis factor receptor-1 (TNFRSF1A) were measured in plasma before and 4h after start of surgery as part of a randomized controlled trial investigating the effect of perioperative gum chewing on the inflammatory response. Multivariable linear regression analysis was performed to assess the effect of myopenia on inflammatory markers while correcting for possible confounders. Results: Four hours after start of surgery, IL-8 was higher in patients with myopenia than in patients without myopenia (352 +/- 268 vs. 239 +/- 211 pg/ml, P = 0.048), while TNFRSF1A was similar between groups. After adjusting for sex and the intervention with perioperative gum chewing, myopenia remained associated with higher postoperative IL-8 concentrations (P = 0.047). Conclusion: Myopenia may affect IL-8 early after colorectal surgery. However, more studies are needed to validate these findings.