Effect of Sarcobesity Index and Body Adipose Tissue Variables on Cardiopulmonary Exercise Testing Performance in Colorectal Surgery Setting: A Retrospective Cohort Study

<b>Aims/Background</b> The prognostic significance of body composition variables has become a popular area of research over the recent years. This study aimed to determine whether adipose tissue variables and sarcobesity index measured by computed tomography (CT) could predict cardiopulmonary exercise testing (CPET) performance and long-term mortality in patients undergoing major colorectal surgery. <b>Methods</b> The Strengthening the Reporting of Cohort Studies in Surgery (STROCSS) statement standards were followed to conduct a retrospective cohort study of consecutive patients who had CPET prior to major colorectal surgery between January 2011 and January 2017. Receiver Operating Characteristic curve analysis was conducted to assess the discriminative performances of adipose tissue variables. The association between CT-derived adipose tissue variables (sarcobesity index, visceral adipose tissue, subcutaneous adipose tissue, and total adipose tissue) and CPET performance and mortality were assessed using regression analyses. <b>Results</b> 457 patients were included. Total adipose tissue evaluated via 2-dimensional (2D) and 3-dimensional (3D) approaches predicted oxygen uptake (<i>V̇</i>O₂) Rest, <i>V̇</i>O₂ anaerobic threshold (AT), ventilatory equivalents for carbon dioxide (<i>V̇</i>E/<i>V̇</i>CO₂) AT, ventilatory equivalents for oxygen (<i>V̇</i>E/<i>V̇</i>O₂) AT, <i>V̇</i>O₂ peak, exercise time, maximum work, peak metabolic equivalents (METS), peak respiratory rate (RER), and peak oxygen pulse. Sarcobesity index (2D and 3D) predicted <i>V̇</i>O₂ Rest, <i>V̇</i>O₂ AT, <i>V̇</i>E/<i>V̇</i>CO₂ AT, <i>V̇</i>O₂ peak, maximum work, peak METS, maximum heart rate, and peak RER. Neither total adipose tissue nor sarcobesity index (2D and 3D) predicted 1-year, 3-year, or 5-year mortality. There was no difference in the discriminative performance of adipose tissue variables in predicting mortality. <b>Conclusion</b> The CPET performance may be predicted by radiologically measured adipose tissue variables and sarcobesity index. However, the prognostic value of the variables may not be significant in this setting.