Healthy Participants, Obese But Otherwise Healthy Participants
Conditions
Keywords
Fructose, Sugar
Brief 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.
Detailed 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 will be performed approximately three weeks apart. Vital signs and anthropometrics will be measured at each clinic visit.
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
Sponsors
Touro University, California
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
20 Years to 55 Years
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 carcinoma or kidney disease stage 3 or higher or patients currently on dialysis; * Use of any anti-diabetic medications or hypolipidemic agents in the past six months; * History of surgical procedure for obesity; * Change in body weight \>5% in the past six months (by self-report); * History of other conditions known to affect insulin sensitivity and lipid metabolism (e.g., polycystic ovary syndrome), history of galactosemia, hereditary fructose intolerance, or who test positive for fructose malabsorption at screening; * Known intolerance to acetaminophen.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Fru-hGNG | 6 hours | Amount of fructose converted to glucose in the liver |
| Fru-iGNG | 6 hours | Amount of fructose converted to glucose in the intestine |
| De novo lipogenesis (DNL) | 6 hours | Percent of newly synthesized palmitate |
| Fru-GNG | 6 hours | Total amount of fructose converted to glucose |
Countries
United States
Contacts
CONTACTSally Chiu, PhD
CONTACTLisa Johnson, RN
PRINCIPAL_INVESTIGATORJean-Marc Schwarz, PhD
Touro University, California
PRINCIPAL_INVESTIGATORGrace M Jones, PhD
Touro University, California
Outcome results
None listed