Abstract
Although body mass index (BMI) is associated with Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD), its relationship with MASLD remission remains underexplored. This retrospective cohort study enrolled 2890 MASLD participants who underwent health examinations at Kuichong People's Hospital in Shenzhen from January 2018 to December 2023. MASLD remission was defined as ultrasound-confirmed complete remission of hepatic steatosis at follow-up. Cox proportional hazards regression models with cubic spline functions assessed the BMI-remission relationship and explored potential nonlinearity. Subgroup and sensitivity analyses confirmed the robustness of findings. After multivariable adjustment, higher BMI was negatively associated with MASLD remission (HR = 0.966, 95% CI 0.942-0.991). A nonlinear relationship was identified with an inflection point at BMI = 22.10 kg/m(2). Below this threshold, BMI showed a significant negative association with remission (HR = 0.929, 95% CI 0.884-0.976). Above it, no significant association was observed. Sensitivity analyses validated the stability of these results. This study reveals a negative and nonlinear BMI-MASLD remission association in Chinese adults, with stronger effects below BMI 22.10 kg/m(2). These findings may provide reference for future prospective studies and clinical consultation regarding the optimization of MASLD management strategies. As a single-center study, multicenter validation is needed to confirm generalizability.