Association between hepatic steatosis and fibrosis with measures of insulin sensitivity in patients with severe obesity and type 2 diabetes - a cross-sectional study.

BACKGROUND: Obesity, non-alcoholic fatty liver disease (NAFLD) and insulin resistance are three pathological conditions highly correlated, but this relationship is not fully elucidated. Hence, we aimed to assess the association of hepatic steatosis and fibrosis with different measures of insulin sensitivity in patients with severe obesity and type 2 diabetes mellitus (T2DM). METHODS: A cross-sectional study (Oseberg trial) including patients with T2DM referred for bariatric surgery at Vestfold Hospital Trust, Norway. Magnetic resonance imaging (MRI) and the enhanced liver fibrosis (ELF) test was used for estimation of liver fat fraction (LFF) and degree of fibrosis, respectively. Oral and intravenous glucose tolerance tests were applied for estimation of insulin sensitivity (HOMA2S, Matsuda ISI and MinMod SI). RESULTS: A total of 100 patients (mean [SD] age 47.5 [9.7] years, 65% women, BMI 42.0 [5.3] kg/m2 and 98% with metabolic syndrome) were included in the analyses. The mean (SD) LFF in the total population was 19.1 (11.5), and the mean (SD) ELF score was 8.46 (0.84), a value representing moderate fibrosis. LFF was inversely associated with HOMA2S and Matsuda ISI, and both measures were significantly higher in the no or low-grade steatosis group compared with the medium-to-high grade steatosis group (mean difference [95% CI] 5.9 [2.2-9.6]%, Cohen's d = 0.75), and (0.7 [0.3-1.1], Cohen's d = 0.80, respectively). There was no association between LFF, as a categorical or continuous variable, and MinMod SI. The proportions of patients with none to mild fibrosis, moderate fibrosis and severe fibrosis were 14, 78 and 6%, respectively, and there were no significant associations between level of fibrosis and measures of insulin sensitivity. CONCLUSIONS: Patients with morbid obesity and T2DM demonstrated high levels of liver fat fraction, and we showed that hepatic steatosis, but not the degree of liver fibrosis, was associated with different measures of insulin sensitivity in patients with severe obesity and T2DM. Further, our results might indicate that the LFF is primarily associated with hepatic, and not peripheral insulin sensitivity. To improve the diagnosis of NAFLD and the prediction of its progression, more studies are needed to reveal the pathological mechanistic pathways involved in NAFLD and insulin sensitivity. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01778738.

Gastric Bypass Versus Sleeve Gastrectomy in Type 2 Diabetes: Effects on Hepatic Steatosis and Fibrosis : A Randomized Controlled Trial.

BACKGROUND: Weight loss improves fatty liver disease. No randomized trial has compared the effects of sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) on liver fat content and fibrosis. OBJECTIVE: To compare the 1-year effects of SG and RYGB on hepatic steatosis and fibrosis. DESIGN: Single-center, randomized, controlled trial (Oseberg [ObesitySurgery in Tønsberg]). (ClinicalTrials.gov: NCT01778738). SETTING: Tertiary care obesity center in Norway. PARTICIPANTS: 100 patients (65% female; mean age, 47.5 years; mean body mass index, 42 kg/m2) with type 2 diabetes mellitus (T2DM). INTERVENTION: From January 2013 to February 2018, patients were randomly assigned (1:1 ratio) to SG or RYGB. MEASUREMENTS: The primary outcome was remission of T2DM (previously published). Predefined secondary outcomes in the present study were hepatic steatosis and fibrosis assessed by magnetic resonance imaging (liver fat fraction), enhanced liver fibrosis (ELF) test, noninvasive indices, and liver enzymes. RESULTS: Liver fat fraction declined similarly after SG (-19.7% [95% CI, -22.5% to -16.9%]) and RYGB (-21.5% [CI, -24.3% to -18.6%]) from surgery to 1-year follow-up, and almost all patients (SG, 94%; RYGB, 100%) had no or low-grade steatosis at 1 year. The ELF score category remained stable in 77% of patients, but 18% experienced worsening of fibrosis at 1 year, with no substantial between-group difference. LIMITATIONS: Single-center study, short follow-up time, and lack of power for secondary outcomes. CONCLUSION: With an almost complete clearance of liver fat 1 year after surgery, RYGB and SG were both highly effective in reducing hepatic steatosis. Bariatric surgery had less influence on degree of fibrosis in the short term, but assessment of long-term progression is warranted. PRIMARY FUNDING SOURCE: Vestfold Hospital Trust and the South-Eastern Norway Regional Health Authority.

Single-centre, triple-blinded, randomised, 1-year, parallel-group, superiority study to compare the effects of Roux-en-Y gastric bypass and sleeve gastrectomy on remission of type 2 diabetes and ß-cell function in subjects with morbid obesity: a protocol for the Obesity surgery in Tønsberg (Oseberg) study.

INTRODUCTION: Bariatric surgery is increasingly recognised as an effective treatment option for subjects with type 2 diabetes and obesity; however, there is no conclusive evidence on the superiority of Roux-en-Y gastric bypass or sleeve gastrectomy. The Oseberg study was designed to compare the effects of gastric bypass and sleeve gastrectomy on remission of type 2 diabetes and ß-cell function. METHODS AND ANALYSIS: Single-centre, randomised, triple-blinded, two-armed superiority trial carried out at the Morbid Obesity Centre at Vestfold Hospital Trust in Norway. Eligible patients with type 2 diabetes and obesity were randomly allocated in a 1:1 ratio to either gastric bypass or sleeve gastrectomy. The primary outcome measures are (1) the proportion of participants with complete remission of type 2 diabetes (HbA1c≤6.0% in the absence of blood glucose-lowering pharmacologic therapy) and (2) ß-cell function expressed by the disposition index (calculated using the frequently sampled intravenous glucose tolerance test with minimal model analysis) 1 year after surgery. ETHICS AND DISSEMINATION: The protocol of the current study was reviewed and approved by the regional ethics committee on 12 September 2012 (ref: 2012/1427/REK sør-øst B). The results will be disseminated to academic and health professional audiences and the public via publications in international peer-reviewed journals and conferences. Participants will receive a summary of the main findings. TRIAL REGISTRATION NUMBER: NCT01778738;Pre-results.