Metabolic and bariatric surgery in MAFLD: a meta-analysis of endocrine outcomes, fibrosis remission, and postoperative complications

Metabolic dysfunction-associated fatty liver disease (MAFLD) is increasingly common among candidates for metabolic and bariatric surgery, yet clinical thresholds defining when surgery is beneficial or contraindicated remain unclear. This systematic review and meta-analysis synthesized evidence from 29 studies including 71,904 patients with biopsy-confirmed or elastography-confirmed MAFLD undergoing sleeve gastrectomy, Roux-en-Y gastric bypass, or other metabolic procedures. Bariatric surgery was associated with marked hepatic and endocrine improvement, with pooled remission rates of 70% for steatohepatitis, 57% for fibrosis, and 59% for type 2 diabetes. Both sleeve gastrectomy and Roux-en-Y gastric bypass achieved comparable metabolic and hepatic benefits, supporting the role of weight-independent mechanisms such as enhanced incretin signaling and improved insulin sensitivity. Postoperative complications occurred in 15% of patients, including 4% major complications, indicating an overall acceptable safety profile. Across studies, patients with compensated cirrhosis experienced meaningful hepatic improvement, whereas those with decompensated cirrhosis, clinically significant portal hypertension, or impaired hepatic reserve had higher morbidity and limited benefit. Endocrine instability-particularly poorly controlled endocrine disease (e.g., uncontrolled diabetes or untreated thyroid dysfunction)-also emerged as a relative contraindication due to impaired healing and unpredictable metabolic responses. These findings underscore the need for careful preoperative evaluation integrating liver staging, endocrine profiling, and metabolic capacity. Overall, bariatric surgery provides substantial hepatic and endocrine benefits for appropriately selected MAFLD patients, while advanced cirrhosis and uncontrolled endocrine disease represent key thresholds at which surgical risk may outweigh benefit. A multidisciplinary liver-endocrine approach is essential for optimal candidate selection and postoperative outcomes.