Metabolic Flux Analysis in Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

Inclusion Criteria:

• Scheduled and clinically cleared for protocol-eligible bariatric surgery at Vanderbilt University Medical Center.
• BMI ≥40 kg/m², or BMI >35 kg/m² with at least one obesity-associated comorbidity, such as type 2 diabetes, cardiovascular disease, hypertension, hyperlipidemia, obstructive sleep apnea, MASLD, osteoarthritis, or polycystic ovarian syndrome.
• Able and willing to complete study procedures, including informed consent, questionnaires, blood draws, MRI/MRE imaging, stable isotope tracer infusion, and research tissue collection during planned bariatric surgery.
• Able to provide informed consent in English.

Exclusion Criteria:

• Contraindication to MRI/MRE, including implanted cardiac defibrillator, pacemaker, or other MRI-incompatible implanted device.
• Prior gastric or intestinal surgery, pancreatic surgery, or other prior surgery that, in the judgment of the study team or bariatric surgeon, would interfere with study procedures or outcome interpretation.
• Active cancer or ongoing cancer treatment.
• Presence or history of HIV infection.
• Alcohol use above study-defined limits: more than 14 alcoholic drinks per week for men or more than 7 alcoholic drinks per week for women, or illicit drug use that would interfere with safe participation or interpretation of study results.
• Anemia or other hematologic condition that would increase risk from study blood collection.
• Abnormal ECG or clinically significant cardiovascular finding that would increase risk from study procedures.
• Impaired renal function or other clinically significant condition that would increase risk from study participation.
• Known Wilson's disease, alpha-1 antitrypsin deficiency, hemochromatosis, or other non-MASLD chronic liver disease that would confound interpretation of study outcomes.
• Any medical, surgical, or safety condition that, in the judgment of the PI, clinical co-investigator, CRC staff, anesthesia team, or bariatric surgeon, would make participation unsafe or interfere with completion of study procedures.