Sugar Metabolism in Nonalcoholic Fatty Liver Disease

Eligibility Details: Inclusion Criteria: Patients must satisfy all of the following criteria to be eligible for enrollment: - Age greater than 18 years as of the initial screening interview and provision of consent - Healthy control as defined by: - normal liver aminotransferases AND - no evidence of NAFLD on radiologic imaging studies AND - no history of chronic liver disease OR - liver biopsy (if one had been historically performed for evaluation of suspected liver disease). OR • Patient with clinically suspected NAFLD as assessed by standard of care measures (risk factors for NAFLD, abnormal liver enzymes and/or fatty liver on imaging studies) who are scheduled to will undergo liver biopsy for the purpose of grading / staging the severity of their underlying liver disease Exclusion Criteria: Patients who satisfy any of the following exclusion criteria will be ineligible for enrollment: - Current or history of significant alcohol consumption for a period of more than 3 consecutive months within 1 year prior to screening (significant alcohol consumption is defined as more than 20 g/day in females and more than 30 g/day in males, on average) - Inability to reliably quantify alcohol consumption based upon local study physician judgment - Use of drugs historically associated with NAFLD (amiodarone, methotrexate, systemic glucocorticoids, tetracyclines, tamoxifen, estrogens at doses greater than those used for hormone replacement, anabolic steroids, valproic acid, and other known hepatotoxins) for more than 2 weeks in the past year prior to randomization - Prior or planned (during the study period) bariatric surgery - Uncontrolled diabetes defined as HbA1c 9.5% or higher within 60 days prior to enrollment - A platelet count below 90,000/mm3 - Clinical evidence of hepatic decompensation as defined by the presence of any of the following abnormalities: - Serum albumin greater than 3.2 g/dL, INR greater than 1.3, bilirubin greater than 2.0 mg/dL - History of esophageal varices, ascites or hepatic encephalopathy - Evidence of other forms of chronic liver disease - Serum alanine aminotransferase (ALT) greater than 300 U/L - Serum creatinine of 2.0 mg/dL or greater - Unstable therapy for components of the metabolic syndrome (ie. recent starting or stopping of insulin sensitizing agent, lipid lowering agent, and/or antioxidant therapy) . Recent starting or stopping (for more than 7 days) the use of a thiazolidinedione (pioglitazone or rosiglitazone) 90 days before the entry biopsy or anytime thereafter - Use of any prescription or over-the-counter medication or herbal remedy that are believed to improve or treat NASH or liver disease or obesity for the 90 days prior to baseline liver biopsy or prior to randomization - Patients must not take any other agent to treat NASH except the treatment assigned after randomization. - Inability to safely obtain a liver biopsy - Active substance abuse including inhaled or injection drugs in the year prior to screening - Pregnancy, planned pregnancy, potential for pregnancy and unwillingness to use effective birth control during the trial, breast feeding - Any other condition which, in the opinion of the investigator, would impede compliance or hinder completion of the study - A contraindication to MRI examinations - Extreme claustrophobia - Weight or girth exceeds the scanner capabilities - Any condition or circumstance that, in the opinion of the site investigator, would interfere with completion of MR examinations - Failure to give informed consent