Weight Loss After Sleeve Gastrectomy According to Metabolic Dysfunction-Associated Steatotic Liver Disease Stage in Patients with Obesity: A Liver Biopsy-Based Prospective Study.

Background: The role of metabolic dysfunction-associated steatotic liver disease (MASLD) in sleeve gastrectomy (SG)-related outcomes remains uncertain. In this study, we aimed to assess the influence of preoperative biopsy-proven MASLD and its stages on weight loss after SG.

Methods: One hundred sixty-three patients with obesity undergoing SG with concomitant intraoperative liver biopsy were followed up for 1 year. Fifty-eight participants were categorized as no MASLD, thirty-eight as metabolic dysfunction-associated steatotic liver (MASL), and sixty-seven as metabolic dysfunction-associated steatohepatitis (MASH). Percentage total weight loss (%TWL) and percentage excess weight loss (%EWL) 1 year after SG were calculated for the different groups. We also evaluated the association between preoperative MASLD (and its stages) and weight loss, after adjusting for potential confounders.

Results: Significant differences among groups were detected in %EWL ( = 0.004, ANOVA test), but not in %TWL ( = 0.079). However, significant differences in %TWL were found when MASH and no MASH (i.e., participants with MASL and participants without MASLD) groups were compared (27.3 ± 9.9 vs. 30.7 ± 9, respectively, = 0.025). In the linear regression model for predicting %EWL 1 year after SG, the presence of MASH was independently associated with a lower %EWL, after adjusting for age, sex, baseline body mass index (BMI), and baseline glycated hemoglobin (HbA1c) (Beta -7.1; 95% CI -13.6, -0.5; = 0.035). The presence of MASLD, liver fibrosis, or advanced liver fibrosis (≥F2) was also associated with lower %EWL after SG in crude models, although they did not remain significant after adjusting for these confounders. The presence of MASH was inversely related to %TWL, although the association did not remain significant after adjustment (Beta -2.7; 95% CI -5.7, 0.2; = 0.069).

Conclusions: MASH may be independently associated with lower %EWL 1 year after SG in patients with obesity.