Sarcopenia is Associated with Perioperative Outcomes in Gastric Cancer Patients Undergoing Gastrectomy

Background: Sarcopenia is a syndrome in which skeletal muscle reduction is the main manifestation of age-related and/or disease-related malnutrition associated with postoperative complications and mortality. Objectives: The aim of the current study was to investigate the association between sarcopenia and postoperative complications as well as the nutrition risk of patients with gastric cancer (GC) who received gastrectomy. In addition, a comparative analysis was performed to evaluate the diagnostic accuracy of total psoas muscle area (TPA) and skeletal muscle area (SMA) in sarcopenia. Methods: Preoperative computed tomography scans were obtained from 279 GC patients who received a gastrectomy from June 2011 to May 2016. TPA and SMA at the level of the third lumbar vertebra (L3) were used as the sarcopenia diagnostic index. Patients were diagnosed with sarcopenia via the total psoas muscle index (TPI) and skeletal muscle index (SMI) methods. TPI and SMI were normalized with the square of the patient's height (m(2)) by TPA and SMA. The Clavien-Dindo complications score system was used to classify the complication extent after gastrectomy. Univariate and multivariate logistic regression analyses were carried out to evaluate the risk factors for postoperative complications. Results: A total of 68 and 125 patients were diagnosed with sarcopenia by TPI and SMI, respectively. Eighty-eight (31.5%) patients experienced postoperative complications. Patients with sarcopenia also had a significantly extended postoperative stay (TPI-sarcopenia, 15.0 days vs. non-sarcopenia, 11.0 days, p < 0.001; and SMI-sarcopenia, 14.0 days vs. non-sarcopenia, 11.0 days, p < 0.001) and hospital stay (TPI-sarcopenia, 22.5 days vs. non-sarcopenia, 17.0 days, p < 0.001; and SMI-sarcopenia, 21.0 days vs. non-sarcopenia, 16.5 days, p < 0.001). Multivariate logistic analysis showed that both TPI-sarcopenia (OR 7.561, p < 0.001) and SMI-sarcopenia (OR 10.085, p < 0.001) were associated with the risk of postoperative complications. Furthermore, univariate analysis showed a high correlation between nutrition risk screening 2002 (NRS2002) and sarcopenia (p < 0.001). A total of 54 (79.4%) of the 68 patients who were classified as having sarcopenia by TPI and 94 (75.3%) of the 125 patients who were classified as having sarcopenia by SMI were diagnosed with nutritional risk. Conclusions: Sarcopenia is associated with the total length of hospital stay, postoperative hospital stay, and severe complications in GC patients undergoing gastrectomy. Moreover, SMI may be a more meaningful index than TPI in reducing the rate of misdiagnosis and in predicting adverse perioperative risk. In addition, sarcopenia may cause severe malnutrition and increases perioperative adverse risk. Thus, both sarcopenia and the NRS2002 nutritional score should be assessed during preoperative nutritional screening and evaluation for GC patients.