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Active, Not Recruiting

NCT Number: NCT04168372

Fructose: Substrate, Stimulus, or Both?

This objective of this study is to use sensitive methodology under controlled conditions to investigate the mechanisms by which fructose consumption contributes to excess fatty acid synthesis and elevations in blood glucose levels following consumption of meals containing fructose.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Insulin Resistance Glucose Intolerance Glucose Metabolism Disorders Hyperglycemia Hyperinsulinism Insulin Sensitivity Metabolic Diseases Nutritional and Metabolic Diseases Pre Diabetes

Age range

20 year–55 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Touro University California

Vallejo, California, 94592, United States

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Body Mass Index 22 to 35 kg/m2
  • Prediabetic (HbA1c 5.7% to 6.5%) or hyperinsulinemic (fasting insulin ≥12 µIU/mL) but non-diabetic (fasting glucose <126mg/dL and HbA1c < 6.5%) ; or normal control (fasting insulin <10 µIU/mL, fasting glucose <100 mg/dL, and HbA1c < 5.7%)

Exclusion criteria

  • Pregnancy or lactation within the past six months
  • Type 1 or 2 diabetes mellitus
  • History of liver disease or aspartate aminotransferase (AST) and alanine aminotransferase (ALT) 2x the upper limit of normal (ULN);
  • Fasting triglyceride or total cholesterol levels above 95th percentile for age and sex;
  • Hemoglobin or hematocrit below the lower limit of normal for sex;
  • Report of hepatitis or HIV infection;
  • History of cancer, use of any anti-diabetic medications or hypolipidemic agents in the past six months;
  • History of surgical procedure for obesity;
  • Self-reported change in body weight >5% in the past six months;
  • History of other conditions known to affect insulin sensitivity and lipid metabolism;
  • Known intolerance to acetaminophen or components of the liquid test meals.

Treatment and study plan

High fructose, fructose labeled meal

Other

Liquid meal containing high fructose (16% of energy), labeled with 2-13C fructose

High fructose, pyruvate labeled meal

Other

Liquid meal containing high fructose (16% of energy), labeled with 2-13C pyruvate

Low fructose, fructose labeled meal

Other

Liquid meals containing low fructose (6% of energy), labeled with 2-13C fructose

Low fructose, pyruvate labeled meal

Other

Liquid meal containing low fructose (6% of energy), labeled with 2-13C pyruvate

Primary outcomes

  1. Hepatic fractional de novo lipogenesis in triglyceride rich lipoprotein (TRL)

    Time frame: 6 hours

    Measured by the detection of 13C carbons in TRL-palmitate from administered 13C labeled pyruvate or 13C labeled fructose.

  2. Rate of appearance of UDP-glucose

    Time frame: 6 hours

    An estimate of hepatic glycogen flux measured by administration of D1 galactose and acetaminophen

  3. Rate of appearance of blood glucose from gluconeogenesis

    Time frame: 6 hours

    Measured by the dilution method of labeled glucose

Secondary outcomes

  1. Serum triglyceride concentration

    Time frame: 6 hours

    Fasting and postprandial serum triglyceride levels

  2. Serum glucose concentration

    Time frame: 6 hours

    Fasting and postprandial serum triglyceride levels

  3. Serum lactate concentration

    Time frame: 6 hours

    Fasting and postprandial serum lactate levels

  4. Serum insulin concentration

    Time frame: 6 hours

    Fasting and postprandial insulin levels

  5. Serum free fatty acid concentration

    Time frame: 6 hours

    Fasting and postprandial fatty acid levels

  6. Enteral (chylomicron) fractional de novo lipogenesis (DNL)

    Time frame: 6 hours

    Measured by the detection of 13C carbons in chylomicron-palmitate from administered 13C labeled pyruvate or 13C labeled fructose.

  7. Hepatic (VLDL) fractional de novo lipogenesis (DNL)

    Time frame: 6 hours

    Measured by the detection of 13C carbons in VLDL-palmitate from administered 13C labeled pyruvate or 13C labeled fructose.

  8. Extrasplanchnic fructose

    Time frame: 6 hours

    Calculated using total plasma fructose, plasma 2-13C fructose enrichment, and endogenous fructose production

  9. Whole body fructose oxidation

    Time frame: 6 hours

    Measured by 13C atom % excess in exhaled breath, and VCO2 by indirect calorimetry

Sponsors and collaborators

Lead sponsor

Touro University, California

Other

Registry information

Important dates

Study start
2019
Primary completion
2026
Study completion
2027
First posted
Nov 19, 2019
Registry last updated
Jul 10, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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