Background: Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease and is found in 70% of obese people. The evidence available to date suggests that bariatric surgery could be an effective treatment by reducing weight and also by improving metabolic complications in the long term. This work aimed to compare, in a diet-induced NAFLD animal model, the effect of both sleeve gastrectomy (SG) and very-low calorie diet (VLCD).
Methods: Thirty-five Wistar rats were divided into control rats (n = 7) and obese rats fed a high-fat diet (HFD). After 10 weeks, the obese rats were subdivided into four groups: HFD (n = 7), VLCD (n = 7), and rats submitted to either a sham operation (n = 7) or SG (n = 7). Both liver tissue and blood samples were processed to evaluate steatosis and NASH changes in histology (Oil Red, Sirius Red and H&E); presence of endothelial damage (CD31, Moesin/p-Moesin, Akt/p-Akt, eNOS/p-eNOS), oxidative stress (iNOS) and fibrosis (αSMA, Col1, PDGF, VEGF) proteins in liver tissue; and inflammatory (IL6, IL10, MCP-1, IL17α, TNFα), liver biochemical function, and hormonal (leptin, ghrelin, visfatin and insulin) alterations in plasma.
Results: Both VLCD and SG improved histology, but only SG induced a significant weight loss, improved endothelial damage, and a decreased cardiovascular risk by reducing insulin resistance (IR), leptin, total cholesterol, and triglyceride levels. There were no relevant variations in the inflammatory and fibrosis markers.
Conclusion: Our study suggests a slight superiority of SG over VLCD by improving not only the histology but also the IR and cardiovascular risk markers related to NAFLD.
Keywords: Bariatric surgery animal model; Endothelial damage; Fatty liver disease; Inflammation; Liver fibrosis; Sleeve gastrectomy; Very low calorie diet.