Gastric Bypass improves Metabolic Dysfunction-Associated Fatty Liver Disease in Low-BMI Patients

A new study found that Roux-en-Y gastric bypass therapy showed good results in patients having low-body mass index with insulin-treated type 2 diabetes and having complete histologic resolution. The study was published in the 'Annals of Surgery.' 

Metabolic dysfunction-associated fatty liver disease (MAFLD) is the multifactorial pathogenesis of fatty liver disease in metabolically sick patients. It is associated with many metabolic diseases like the type 2 diabetes (T2D), dyslipidemia, and obesity. There is uncertainty on the effects of metabolic surgery on MAFLD. Hence, researchers conducted a study to assesses the impact of Roux-en-Y gastric bypass (RYGB) on MAFLD in a prototypical cohort outside the guidelines for obesity surgery. 

A prospective, single-arm trial was carried out on twenty patients investigating the effects of RYGB on advanced metabolic disease. Patients aged 18 to 70 years having an insulin-dependent type 2 diabetes, with a body mass index of 25 to 35 kg/m2, glucagon-stimulated C-peptide of >1.5 ng/mL, glycated hemoglobin >7%, were included in the study. A RYGB with intraoperative liver biopsies and follow-up liver biopsies 3 years later was performed. Liver pathologists assessed the Steatohepatitis. Data were analyzed using the Wilcoxon rank sum test and a P value <0.05 was defined as significant. 

Results: 

• MAFLD completely resolved after RYGB while fibrosis improved as well in all patients after 3 years.
• Fifty-five percent were off insulin therapy with a significant reduction in glycated hemoglobin.
• By upregulation of NRF1 and its dependent antioxidative and mitochondrial genes, RYGB reduced systemic and hepatic nitrotyrosine levels.
• Central metabolic regulators such as SIRT1 and FOXO1 were upregulated while de novo lipogenesis was reduced, and β-oxidation was improved in line with an improvement of insulin resistance.
• Lastly, gastrointestinal hormones and adipokines secretion were changed favorably. 

Thus, in low-body mass index patients with insulin-treated type 2 diabetes and with complete histologic resolution, RYGB appears to be a promising therapy for MAFLD. It also restores the oxidative balance, adipose tissue function, and gastrointestinal hormones. 

Further reading: 10.1097/SLA.0000000000005631 

Billeter AT, Scheurlen KM, Israel B, Straub BK, Schirmacher P, Kopf S, Nawroth PP, Müller-Stich BP. Gastric Bypass Resolves Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD) in Low-BMI Patients: A Prospective Cohort Study. Ann Surg. 2022 Nov 1;276(5):814-821.