Phase Angle, Inflammation, and Sarcopenia in Late Postoperative Roux-En-Y Gastric Bypass

Sarcopenic obesity is characterized by a disproportion between the amount of muscle to fat. Contrary to most studies evaluating parameters related to sarcopenic obesity in the elderly, this study aims to evaluate the phase angle (PhA) and sarcopenia in young individuals pre- and post-Roux-en-Y gastric bypass. A total of 69 volunteers (46 women and 23 men; 38.5 ± 8.1 years) participated in this study. Body composition and PhA were assessed using BIA. Sarcopenia was assessed using a handgrip strength test (HGS) and gait speed (GS), and appendicular lean mass (ALM) was assessed using Dual Energy X-ray Absorptiometry (DXA). The PhA was significantly lower (p < 0.0007) and the resistance (R) significantly higher (p = 0.0026) in the postoperative group. HGS was negatively correlated with R (r = −0.63669; p < 0.0001), hs-CRP (r = −0.45436; p = 0.0197), and leptin (r = −0.46505; p = 0.0043). GS was negatively correlated with R (r = −0.36220; p = 0.0254), and ALM was negatively correlated with reactance (r = −0.49485; p = 0.0034) and R (r = −0.65797; p ≤ 0.0001). PhA and other components of BIA provide a good correlation with sarcopenia, especially regarding the reduction in muscle function, in an early form, in individuals in the pre- and postoperative period of gastric bypass.