Abstract
BACKGROUND: The impact of body fat content on the treatment efficacy of extracorporeal shock wave lithotripsy (ESWL) for pancreatic duct stones (PDS) remains unclear, and there is a paucity of targeted analyses on refined body composition parameters in existing studies. This study aims to investigate the associations between body mass index (BMI), body fat percentage, visceral adipose tissue/skeletal muscle tissue (VAT/SMT) ratio, and the treatment efficiency of ESWL for PDS. METHODS: This was a single-center retrospective observational study that enrolled 147 patients with PDS who underwent ESWL and achieved complete stone clearance at Gongli Hospital, Pudong New Area, Shanghai, from January 2021 to January 2025. Measurements of VAT, subcutaneous adipose tissue (SAT), and SMT at the level of the L3/L4 intervertebral space were performed using non-contrast computed tomography (CT) combined with Adobe Photoshop software, and the VAT/SMT ratio was calculated accordingly. Hierarchical stepwise linear regression models were employed to analyze the independent effects of body fat-related parameters (including BMI, body fat percentage, and VAT/SMT ratio) on lithotripsy time and the number of lithotripsy sessions, after adjusting for confounding variables such as gender, age, and stone cross-sectional area. RESULTS: Pearson correlation analysis revealed that body fat percentage exhibited a strong positive correlation with the total lithotripsy time (r = 0.544, P < 0.001) and the number of lithotripsy sessions (r = 0.546, P < 0.001). Meanwhile, BMI (r = 0.354∼0.382, P < 0.001) and the VAT/SMT ratio (r = 0.352tsim0.353, P < 0.001) showed a moderate positive correlation with both outcomes. Multivariate linear regression analysis (fully adjusted model) confirmed that body fat percentage (number of lithotripsy sessions: β = 0.38, P < 0.001; total lithotripsy time: β = 0.37, P < 0.001), BMI (number of lithotripsy sessions: β = 0.27, P < 0.001; total lithotripsy time: β = 0.32, P < 0.001), and the VAT/SMT ratio (number of lithotripsy sessions: β = 0.20, P = 0.017; total lithotripsy time: β = 0.18, P = 0.035) were all independent positive predictors of lithotripsy efficiency. Additionally, stone cross-sectional area also significantly influenced the outcomes (number of lithotripsy sessions: β = 0.23, P = 0.001; total lithotripsy time: β = 0.15, P = 0.027). CONCLUSION: BMI, body fat percentage, and VAT/SMT ratio exhibit a significant positive correlation with the total lithotripsy time and number of lithotripsy sessions for ESWL in PDS. Among these parameters, body fat percentage has the strongest association with lithotripsy efficiency and maintains a stable independent predictive effect in multivariate models. TRIAL REGISTRATION: Clinical study registration number: GLYY1s2025-032.