Background and objectives: Sarcopenic obesity (SO) is an emerging problem, especially in candidates for bariatric surgery (BS). We hypothesized that musculoskeletal ultrasound (MUS), a simple and accessible method, could be a reliable index of SO. Materials and Methods: A cross-sectional pilot study including 122 subjects (90 cases and 32 controls, 73% female, mean age: 51.2 years) who underwent BS was conducted at University Hospital Mútua Terrassa. The lean mass (LM) was calculated by bioelectrical impedance analysis (BIA) and the thigh muscle thickness (TMT) by MUS. To identify the subjects with SO by BIA, we used skeletal muscle index (SMI). The validity of MUS was determined using the ROC curve. Results: The mean BMI in the obesity group was 44.22 kg/m². We observed a correlation between the LM and SMI assessed by BIA and the TMT assessed by MUS (R = 0.46, p < 0.001). This correlation was maintained at significant levels in the SO group (n = 40): R = 0.79; p = 0.003). The TMT assessed by MUS was able to predict SMI using BIA (AUC 0.77; 95% CI: 0.68242 to 0.84281). The optimal cut-off point for maximum efficiency was 1.57 cm in TMT (sensitivity = 75.6% and specificity = 71.1%). Conclusions: The TMT of the quadriceps assessed by US is a useful tool for identifying subjects with SO. Larger studies to validate this simple low-cost screening strategy are warranted.

Background: Bariatric surgery (BS) has a significant impact on body composition (BC) and consequently may affect established sarcopenic obesity (SO) in candidate patients. The aim of this study was to assess the utility of muscle ultrasound (MUS) of rectus femoris thickness (RFT) for the evaluation of BC and skeletal muscle function in patients undergoing BS compared to bioimpedance analysis (BIA), dual-energy X-ray absorptiometry (DEXA) and dynamometry. On the other hand, we aimed to demonstrate how MUS of RFT correlates with quality of life (QoL) in this population, likely due to its ability to detect regional quadriceps muscle sarcopenia compared to the other mentioned methods. Methods: This was a prospective pilot study that included 77 participants (64.9% female, mean age: 53.2 ± 8.67 years) who underwent BS. Handgrip strength was measured using a dynamometer, fat-free mass index (iFFM) was assessed by BIA, appendicular muscle index (AMI) was calculated using DEXA, and RFT was measured by MUS. Moreover, homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. All these measurements were conducted 1 month prior to BS and at the 12-month follow-up. QoL was assessed using the Moorehead–Ardelt questionnaire. Results: The mean BMI decreased by 12.95 ± 3.56 kg/m² (p = 0.001). Firstly, we observed a positive correlation pre-surgery between HOMA and RFT (r = 0.27, p = 0.02), iFFM (r = 0.36, p = 0.001), AMI (r = 0.31, p = 0.01) and dynamometer readings (r = 0.26, p = 0.02). In addition, we found a correlation between RFT and iFFM (pre-surgery: r = 0.31, p = 0.01; post-surgery: r = 0.25, p = 0.05) and between RFT and lower-extremity AMI post-surgery (r = 0.27, p = 0.04). Secondly, we observed significant reductions in iFFM, AMI and RFT (p = 0.001), but not in dynamometer readings (p = 0.94). Finally, a tendency to a positive correlation between QoL questionnaire and RFT post-surgery results (r = 0.23, p = 0.079) was observed. Conclusions: Our results suggest that RFT measured by MUS is useful for evaluating SO and for the follow-up of these patients after BS. Moreover, RFT can provide relevant information about regional sarcopenia and probably has an accurate correlation with QoL in comparison with the other methods.

Background: Bariatric surgery (BS) has a significant impact on body composition (BC) and con-sequently may affect established sarcopenic obesity (SO) in candidate patients. The aim of this study is to assess the utility of muscle ultrasound (MUS) of rectus femoris thickness (RFT) for the evalua-tion of BC and skeletal muscle function in patients undergoing BS compared to bioimpedance analysis (BIA), dual-energy X-ray absorptiometry (DEXA) and dynamometry. On the other hand, we aim to demonstrate how MUS of RFT correlates better with the quality of life (Qol) in this population, likely because it enables the detection of regional quadriceps muscle sarcopenia, in comparison to the other mentioned methods. Methods: This is a prospective pilot study including 77 subjects (64.9% female, mean age: 53.2 ± 8.67 years) who underwent BS. Handgrip strength was measured using a dynamometer, fat-free mass index (iFFM) was assessed by BIA, appendicular muscle index (AMI) was calculated using DEXA and RFT was measured by MUS. Moreover, Homeostasis Model Assessment of Insulin Resintance (HOMA-IR) was calculated. All these measurements were conducted 1 month prior to BS and at the 12-month follow-up. QoL was as-sessed using the Moorehead-Ardelt questionnaire. Results: The mean BMI decreased by 12.95 ± 3.56 kg/m2 (p=0.001). Firstly, we observed positive correlation pre-surgery between HOMA and: RFT (r=0.27, p=0.02), iFFM (r=0.36, p=0.001), AMI (r=0.31, p=0.01) and dynamometer (r=0.26, p=0.02). In addition, we found correlation between RFT and iFFM (pre-surgical: r=0.31, p=0.01; post-surgical: r=0.25, p=0.05) and between RFT and lower extremities AMI post-surgical (r=0.27, p=0.04). Secondly, we observed significant reductions in iFFM, AMI and RFT (p=0.001), but not with dynamometer (p=0.94). Finally, a tendency to a positive correlation between QoL question-naire and RFT post-surgery (r=0.23, p=0.079) was observed. Conclusions: Our results suggest that RFT measured by MUS for the evaluation of SO and the follow-up after BS of these patients. Moreover, RFT can provide relevant information about regional sarcopenia and probably has an accurate correlation with QoL in comparison with the other methods.

Background/Objectives: Obesity is associated with cognitive decline, and metabolic bariatric surgery (MBS) can improve both physical and cognitive outcomes. However, cognitive improvements post-surgery are variable. This study explores the role of skeletal muscle health, specifically muscle strength and mass, in cognitive performance after MBS, aiming to identify factors that influence cognitive recovery. Methods: In this prospective study, 55 patients scheduled for MBS were assessed 1 month before and 12 months after surgery. Body composition, including appendicular lean mass (ALM) and fat mass, was measured using dual-energy X-ray absorptiometry (DXA). Handgrip strength (HGS) was assessed via dynamometry, and neurocognitive performance was evaluated using a standardized test battery. Results: Significant improvements in cognitive performance were observed at 12 months post-surgery in attention, memory, language, executive functions and overall cognitive performance. Regarding body composition, significant reductions were observed in fat mass and body mass index (BMI). A decrease in ALM and no changes in HGS were observed; however, when adjusted for body size, both showed an increase. Regression analysis identified baseline HGS, but not muscle mass, as a significant predictor of cognitive performance at 12 months post-surgery. Conclusions: MBS leads to significant improvements in cognitive function. Our results suggest that baseline HGS may play a role in predicting cognitive outcomes post-surgery, highlighting the need for comprehensive assessments of both physical and cognitive health in patients undergoing MBS. Further longitudinal studies are needed to explore causal relationships and the potential reversibility of cognitive deficits post-surgery.