Il “Journal of Hepatology” (Volume 60, Issue 2 , Pages 377-383, febbraio 2014) ha pubblicato uno studio in relazione agli effetti della chirurgia bariatrica sulla sensibilità all’insulina epatica, che risulta sensibilmente migliorata già dopo sei mesi dall’intervento chirurgico. Detti effetti metabolici sono stati accompagnati da una marcata riduzione del volume epatico e del contenuto di grassi.
Background & Aims
Bariatric surgery reduces weight and improves glucose metabolism in obese patients. We investigated the effects of bariatric surgery on hepatic insulin sensitivity.
Twenty-three morbidly obese (nine diabetic and fourteen non-diabetic) patients and ten healthy, lean control subjects were studied using positron emission tomography to assess hepatic glucose uptake in the fasting state and during euglycemic hyperinsulinemia. Magnetic resonance spectroscopy was performed to measure liver fat content and magnetic resonance imaging to obtain liver volume. Obese patients were studied before bariatric surgery (either sleeve gastrectomy or Roux-en-Y gastric bypass) and six months after surgery.
Insulin-induced hepatic glucose uptake was increased by 33% in non-diabetic and by 36% in diabetic patients at follow-up compared with baseline, but not totally normalized. The liver fat content was reduced by 76%, liver volume by 26% and endogenous glucose production by 19% in non-diabetic patients. The respective changes in diabetic patients were 73%, 24%, and 25%. Postoperatively, liver fat content and endogenous glucose production were almost normalized to lean controls, but liver volume remained greater than in control subjects.
This study shows that bariatric surgery leads to a significant improvement in hepatic insulin sensitivity: insulin-stimulated hepatic glucose uptake was improved and endogenous glucose production reduced when measured, six-months, after surgery. These metabolic effects were accompanied by a marked reduction in hepatic volume and fat content. Overall, the gain in hepatic insulin sensitivity in diabetic patients was quite similar to non-diabetic patients for the same weight reduction.
Abbreviations: BS, bariatric surgery, T2DM, type 2 diabetes, EGP, endogenous glucose production, HGU, hepatic glucose uptake, VLCD, very-low-calorie diet, PET, positron emission tomography, 18F-FDG, 18F-fluorodeoxyglucose, MRI, magnetic resonance imaging, SG, sleeve gastrectomy, RYGB, Roux-en-Y gastric bypass, OGTT, oral glucose tolerance test, MRS, magnetic resonance spectroscopy, LFC, liver fat content, HbA1c, glycosylated haemoglobin, hs-CRP, high-sensitivity C-reactive protein, IL-6, interleukin-6, IL-8, interleukin-8, MCP-1, monocyte chemotactic protein-1, GLP-1, glucagon-like peptide-1