SCCA-IgM as a Potential Biomarker of Non-Alcoholic Fatty Liver Disease in Patients with Obesity, Prediabetes and Diabetes Undergoing Sleeve Gastrectomy.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) has a high prevalence in obesity and its presence should be screened. Laparoscopic sleeve gastrectomy (LSG) is an effective treatment for obesity, but its effects on NAFLD are still to be firmly established. The diagnosis of non-alcoholic steatohepatitis (NASH) is currently performed by liver biopsy, a costly and invasive procedure. Squamous cell carcinoma antigen-IgM (SCCA-IgM) is a biomarker of viral hepatitis to hepatocellular carcinoma development and its role in NAFLD to NASH progression has not yet been investigated. OBJECTIVE: The aim of this study was to evaluate SCCA-IgM as a non-invasive biomarker of NAFLD/NASH in patients with different degrees of metabolic-complicated obesity before and after LSG. METHOD: Fifty-six patients with obesity were studied before and 12 months after LSG; anthropometric, biochemical, clinical, and imaging data were collected. RESULTS: At baseline steatosis was strongly associated with the glycaemic profile (p = 0.016) and was already present in prediabetic patients with obesity (82%). Only 3 patients had an SCCA-IgM level above the normal cut-off. SCCA-IgM titre did not change according to glycaemic profile or steatosis. Metabolic and inflammatory factors and transaminases significantly reduced after LSG-induced weight loss, except for SCCA-IgM. The ALT/AST ratio decreased post-LSG correlated with BMI (r = 0.297, p = 0.031), insulin (r = 0.354, p = 0.014), and triglycerides (r = 0.355, p = 0.009) reduction. CONCLUSIONS: Our results confirm the tight link between NAFLD and metabolic complications, suggesting prediabetes as a new risk factor of steatosis. SCCA-IgM does not seem to have a role in the identification and prognosis of NAFLD.

Modifications of Resting Energy Expenditure After Sleeve Gastrectomy.

OBJECTIVES: Resting energy expenditure (REE) declines more than what is expected according to body composition changes after caloric restriction. This metabolic adaptation is considered one of the factors favoring weight regain. The aim of this study is to evaluate the changes of REE and calculate the degree of metabolic adaptation occurring after laparoscopic sleeve gastrectomy (LSG). METHODS: REE (by indirect calorimetry) and body composition (fat-free mass or FFM, fat mass or FM by bioelectrical impedance analysis) were determined before and after 12 months in 154 patients with obesity treated with laparoscopic sleeve gastrectomy (LSG). RESULTS: Weight loss was 29.8 ± 10.6%, with corresponding relative reductions in FM (44.5 ± 22.8%), FFM (13.7 ± 9.9%), and REE (27.3 ± 12.9%). A predictive equation for REE was computed by using the baseline FFM and FM values to account for body composition changes. A predicted post-weight loss REE was calculated by using this equation and entering post-weight loss body composition values. Observed post-surgery REE was significantly lower than predicted one (1410 ± 312 vs 1611 ± 340 kcal/day, P < 0.001) and metabolic adaptation, calculated as the difference between observed and predicted post-weight loss REE, was - 199 ± 238 kcal/day. The post-surgery level of metabolic adaptation was inversely related to postoperative percent weight loss (r = - 0.170; P < 0.05) and FM loss (r = - 0.245; P < 0.01). CONCLUSIONS: A significant reduction of resting energy expenditure and a significant degree of metabolic adaptation both occur after sleeve gastrectomy. A greater metabolic adaptation could be partly responsible for a lower weight loss after surgery.