Supplementary Material for: Body Composition and Function in Patients with Obesity in Clinical Practice. Beyond the BMI.

Introduction: Assessing the nutritional and morphofunctional status of patients with obesity is essential for optimizing their management. Nutritional ultrasound (NU) is a non-invasive, portable technique that offers insights into muscle and adipose tissue status. Combining NU with bioelectrical impedance analysis (BIA) and handgrip strength (HGS) may improve the assessment of body composition and muscle functionality. This study aimed to evaluate the usefulness of NU as a primary tool for morphofunctional assessment in patients with obesity, while comparing and complementing it with BIA and HGS.
Results: In a cohort of 178 patients with obesity, we analyzed body composition using NU, BIA and HGS, which are widely accepted methods for assessing body composition and muscle strength, respectively. Significant correlations were found between NU-measured quadriceps rectus femoris cross-sectional area (CSA) and BIA-derived fat-free mass markers, such as body cell mass (r = 0.638, P < 0.001) and appendicular skeletal muscle mass (r = 0.591, P < 0.001). Additionally, leg subcutaneous adipose tissue (L-SAT) measured by NU was highly correlated with BIA-measured fat mass (r = 0.656, P < 0.001). Linear regression analyses further confirmed the importance of RF-CSA as a strong predictor of body cell mass (BCM), along with HGS and BMI, explaining 78.2% of the variability in BCM (R² = 0.782, AIC = 672).
Conclusion: These findings suggest that NU, combined with BIA and HGS, provides a comprehensive, practical tool for assessing body composition and muscle function in obesity management, with the potential for routine application in clinical settings.

引言：评估肥胖患者的营养与形态功能状态，对于优化其临床管理方案至关重要。营养超声（Nutritional Ultrasound, NU）是一种无创、便携的检测技术，可用于获取肌肉与脂肪组织的状态信息。将营养超声与生物电阻抗分析（Bioelectrical Impedance Analysis, BIA）、握力（Handgrip Strength, HGS）相结合，或可提升人体成分与肌肉功能的评估效能。本研究旨在评估营养超声作为肥胖患者形态功能评估核心工具的实用性，并与生物电阻抗分析和握力进行对比与补充验证。
结果：本研究纳入178例肥胖患者队列，分别采用营养超声、生物电阻抗分析及握力——二者分别为当前广泛认可的人体成分与肌肉力量评估方法——对受试者进行检测分析。研究发现，营养超声测得的股直肌横截面积（Quadriceps Rectus Femoris Cross-sectional Area, CSA）与生物电阻抗分析得出的无脂体重相关指标存在显著相关性：其中体细胞量（Body Cell Mass, BCM）的相关系数r=0.638，P<0.001；四肢骨骼肌量的相关系数r=0.591，P<0.001。此外，营养超声测得的腿部皮下脂肪组织（Leg Subcutaneous Adipose Tissue, L-SAT）与生物电阻抗分析测得的脂肪量亦呈高度相关（r=0.656，P<0.001）。线性回归分析进一步证实，股直肌横截面积与握力、身体质量指数（BMI）同为体细胞量的强预测因子，可解释78.2%的体细胞量变异度（R²=0.782，AIC=672）。
结论：本研究结果表明，将营养超声与生物电阻抗分析、握力相结合，可为肥胖患者的人体成分与肌肉功能评估提供一套全面且实用的检测方案，具备在临床场景中常规应用的潜力。