Hepatic Gene Response to Intravenous Glucose in Obese Patients With and Without MASLD Undergoing Bariatric Surgery

Inclusion Criteria: To be eligible to participate in this study, a subject must meet all of the following criteria: Adult individuals, age \>35 \< 65 years old. Stable weight (no more than 3% TWL of initial body weight from screening to surgery) Subjects should be able to give informed consent Subjects agree to have tissue biopsies performed during surgery, that is 2 liver, subcutaneous, visceral and omental biopsies plus a one-time jejunal biopsy. For obese non-MASLD patients: * Adult individuals, age \>35 \< 65 years old. * BMI ≥ 40 kg/m², or a BMI ≥ 35 kg/m² with an obesity-related comorbidity * No MASLD based on Fibroscan * Estimated glomerular filtration rate (eGFR) \> 60mL/min/1.73m2 For obese MASLD patients: * MASLD diagnosis according to Fibroscan * Compensated liver disease with the following hematologic and biochemical criteria on entry into study: * ALAT \<10x ULN * Hemoglobin \> 11g/dL for females and 12 g/dL for males * White blood cell (WBC) \> 2.5 K/ μL * Neutrophil count \> 1.5 K μL * Platelets \> 100 K/μL * Total bilirubin \<35 μmol/L * Albumin \>30 g/L * TP \>80% or INR \<1.4 * Serum creatinine \<1.3 mg/dL (men) or \<1.1 mg/dL (women) or * Estimated glomerular filtration rate (eGFR) \> 60mL/min/1.73m2 Exclusion Criteria: A potential subject who meets any of the following criteria will be excluded from participation in this study: * Use of metformin and SGLT2/ exogenous insulin/GLP-1 RA * Primary lipid disorder * Known genetic basis for insulin resistance or glucose intolerance * All medical and psychiatric conditions except for obesity related diseases. * Uncontrolled hypertension (RR \> 150/95 mmHg) * Chronic kidney disease (creatinine \> 150 umol/L) * Pregnancy, females who are breastfeeding * Evidence of another form of liver disease * History of sustained excess alcohol ingestion: daily consumption \>30g/day (3 drinks per day) for males and \>20 g/day (2 drinks per day) for females * Significant systemic or major illnesses other than liver disease, including congestive heart failure (class C and D of the AHA), unstable coronary artery disease, cerebrovascular disease, pulmonary disease, kidney failure, organ transplantation, serious psychiatric disease, active malignancy, compromised immunity * Body mass index (BMI) \>45 kg/m2 * Type 1 or type 2 diabetes * Hemostasis disorders or current treatment with anticoagulants * Known heart failure * Contra-indication for liver biopsy History of/or current cardiac dysrhythmias and/or a history of cardiovascular events including myocardial infarction, except patients with only well-controlled hypertension