Fructose Metabolism Effects on the Liver: Unraveling the Role of Defective Intestinal GNG in Individuals With Obesity
Touro University, California
Summary
This study will test the hypothesis that within a defined range of fructose intake, the ability to convert fructose to glucose (via gluconeogenesis) in the small intestine plays a protective role for the liver, shielding it from the deleterious effects of fructose. We will investigate whether this protective effect of the intestine is impaired in individuals with obesity.
Description
Qualified participants will undergo a sugar tolerance test at baseline and then randomized to undergo four separate outpatient tracer/feeding studies in a crossover fashion. After an overnight fast, a six-hour fed tracer study will be initiated, during which participants will consume liquid meals containing stable isotopes at regular intervals and receive other isotopes intravenously. Meal composition will differ only by fructose content (High vs. Low) and tracer (oral vs. intravenous 13C-labeled fructose). Blood and urine samples will be collected frequently throughout the study. Each visit w…
Eligibility
- Age range
- 20–55 years
- Sex
- All
- Healthy volunteers
- Yes
Inclusion Criteria: * BMI 30 to 38 kg/m2 (obese group) or BMI 19 to 25 kg/m2 (lean group) Exclusion Criteria: * Pregnancy or lactation within the past six months; * Type 1 or 2 diabetes mellitus (including fasting glucose ≥126 mg/dL, HgbA1c ≥6.5%); * History of liver disease or AST and ALT 2x above the upper limit of normal; * Fasting triglyceride \> 300 mg/dl; total cholesterol levels above the 95th percentile for age and sex; * Hemoglobin (Hgb) \<12.5g/d or hematocrit\<3x Hgb value; * Report of HIV or hepatitis B or C infection; * History of cancer, other than basal cell or squamous cell…
Interventions
- OtherHigh fructose meal
Liquid meals containing 55% total carbohydrate (16% fructose), 30% fat, 15% protein.
- OtherLow fructose meal
55% total carbohydrate (6% fructose), 30% fat, 15% protein.
- Other13C labeled fructose, oral
Tracer amount of 13C labeled fructose administered orally in the meals.
- Other13C labeled fructose, intravenous
Tracer amount of 13C fructose administered intravenously
Location
- Touro University CaliforniaVallejo, California