Body Composition in Resectable Non-Small Cell Lung Cancer Patients With Preoperative Sarcopenia: A Propensity-Matched Analysis.

BACKGROUND

Sarcopenia is a prognostic factor in patients with early-stage non-small cell lung cancer (NSCLC). Previous studies have focused on muscle loss, yet comprehensive body composition (BC) alterations in this population remain poorly characterized. This study aimed to delineate BC alterations using bioelectrical impedance analysis (BIA) in early-stage NSCLC patients with preoperative sarcopenia, with a specific focus on sex-specific disparities and the identification of independent BC factors associated with sarcopenia.

METHODS

In this case-control study, 460 patients with Stage I-II NSCLC were initially enrolled from two tertiary hospitals in Anhui, China. Sarcopenia was diagnosed preoperatively based on Asian Working Group for Sarcopenia 2019 criteria. Multifrequency BIA was performed within 48 h before surgery. Propensity score matching (PSM) at a 1:4 ratio was applied to balance covariates (age, sex, height, physical activity, nutritional status, clinical stage, histology, extent of resection and diabetes). Multivariable logistic regressions were used to examine the associations between BC parameters and sarcopenia.

RESULTS

After PSM, 47 sarcopenic and 162 nonsarcopenic patients were well-matched. Sarcopenic patients exhibited systemic depletion beyond reduced muscle mass, including lower body fat mass (BFM: 12.70 vs. 18.60 kg), body cell mass (BCM: 23.90 vs. 29.10 kg), bone mineral content (BMC: 2.22 vs. 2.52 kg = 0.002), basal metabolic rate (BMR: 1151.00 vs. 1340.50 kcal) and elevated extracellular water/intracellular water ratio (ECW/ICW: 0.64 vs. 0.63; all p < 0.001). Distinct sex-specific phenotypes were identified: Sarcopenic females demonstrated coordinated reductions in muscle, fat and minerals (appendicular skeletal muscle mass [ASM]: 13.10 vs. 15.43 kg; BFM: 11.20 vs. 19.20 kg; percent body fat [PBF]: 25.41% vs. 32.88%; BMC: 2.05 vs. 2.26 kg; all p < 0.001), whereas males exhibited isolated muscle loss with preserved adiposity and minerals (PBF: 23.04% vs. 24.29%, p = 0.463; BMC: 2.64 vs. 2.80 kg, p = 0.141). In the fully adjusted model, ASM (OR = 0.03, 95%CI: 0.01-0.08), BFM (OR = 0.81, 95%CI: 0.75-0.87) and BMR (OR = 0.95, 95%CI: 0.94-0.97) were independent factors associated with sarcopenia. Sex significantly modified associations for waist-hip ratio, soft lean mass, FFM and PBF (all p for interaction < 0.05). Sensitivity analyses based on sarcopenia severity supported the robustness of the primary findings.

CONCLUSIONS

Preoperative sarcopenia in early-stage NSCLC involves multicompartment depletion accompanied by cellular dysfunction and metabolic impairment, exhibiting distinct sex-specific phenotypes. BIA provides a practical tool for multidimensional BC assessment, necessitating to integrate it into clinical workflows and developing sex-tailored prehabilitation strategies.