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

Abstract

Aims/Background 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. Methods 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. Results 457 patients were included. Total adipose tissue evaluated via 2-dimensional (2D) and 3-dimensional (3D) approaches predicted oxygen uptake (V̇O₂) Rest, V̇O₂ anaerobic threshold (AT), ventilatory equivalents for carbon dioxide (V̇E/V̇CO₂) AT, ventilatory equivalents for oxygen (V̇E/V̇O₂) AT, V̇O₂ peak, exercise time, maximum work, peak metabolic equivalents (METS), peak respiratory rate (RER), and peak oxygen pulse. Sarcobesity index (2D and 3D) predicted V̇O₂ Rest, V̇O₂ AT, V̇E/V̇CO₂ AT, V̇O₂ 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. Conclusion 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.