Insulin ResistanceNCT04168372
Fructose: Substrate, Stimulus, or Both?
A study testing High fructose, fructose labeled meal, High fructose, pyruvate labeled meal and Low fructose, fructose labeled meal in people with Insulin Resistance and Insulin Sensitivity, run by Touro University, California at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 20 to 55 yearsHealthy volunteers can take part
- Conditions the study is for
- Insulin Resistance, Insulin Sensitivity, Pre Diabetes
- What is being tested?
- High fructose, fructose labeled meal, High fructose, pyruvate labeled meal and Low fructose, fructose labeled meal
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 35 participants
- Where
- 1 siteUnited States
- Study dates
- 15 Sep 2019to 20 Jul 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 55 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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%)
Who cannot join
- 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;
Show all 11Show fewer
- 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.
Trial locations and contacts
1 site in 1 country.
United States1 site
Touro University California
Vallejo, California, 94592
About this study
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.
- Conditions
- Insulin Resistance, Insulin Sensitivity, Pre Diabetes
- Being tested
- High fructose, fructose labeled meal, High fructose, pyruvate labeled meal, Low fructose, fructose labeled meal, Low fructose, pyruvate labeled meal
- Keywords
- Fructose, Glucose, Lipogenesis
- Medical subject headings
- Insulin Resistance, Glucose Intolerance
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
High fructose, fructose labeled mealOther
Liquid meal containing high fructose (16% of energy), labeled with 2-13C fructose
High fructose, pyruvate labeled mealOther
Liquid meal containing high fructose (16% of energy), labeled with 2-13C pyruvate
Low fructose, fructose labeled mealOther
Liquid meals containing low fructose (6% of energy), labeled with 2-13C fructose
Low fructose, pyruvate labeled mealOther
Liquid meal containing low fructose (6% of energy), labeled with 2-13C pyruvate
| Study group | Role | What they receive |
|---|---|---|
| High fructose meal, with fructose label | Experimental | 2-13C fructose incorporated into a meal with high fructose content Receives: Other: High fructose, fructose labeled meal |
| High fructose meal, with pyruvate label | Experimental | 2-13C pyruvate incorporated into a meal with high fructose content Receives: Other: High fructose, pyruvate labeled meal |
| Low fructose meal, with fructose label | Experimental | 2-13C fructose incorporated into a meal with low fructose content Receives: Other: Low fructose, fructose labeled meal |
| Low fructose meal, with pyruvate label | Experimental | 2-13C pyruvate incorporated into a meal with low fructose content Receives: Other: Low fructose, pyruvate labeled meal |
What is being measured
The primary outcome is the main question the study is designed to answer.
Hepatic fractional de novo lipogenesis in triglyceride rich lipoprotein (TRL)
Measured by the detection of 13C carbons in TRL-palmitate from administered 13C labeled pyruvate or 13C labeled fructose.
Measured: 6 hours
Rate of appearance of UDP-glucose
An estimate of hepatic glycogen flux measured by administration of D1 galactose and acetaminophen
Measured: 6 hours
Rate of appearance of blood glucose from gluconeogenesis
Measured by the dilution method of labeled glucose
Measured: 6 hours
Secondary outcomes (9)
Serum triglyceride concentration
Fasting and postprandial serum triglyceride levels
Measured: 6 hours
Serum glucose concentration
Fasting and postprandial serum triglyceride levels
Measured: 6 hours
Serum lactate concentration
Fasting and postprandial serum lactate levels
Measured: 6 hours
Serum insulin concentration
Fasting and postprandial insulin levels
Measured: 6 hours
Serum free fatty acid concentration
Fasting and postprandial fatty acid levels
Measured: 6 hours
Enteral (chylomicron) fractional de novo lipogenesis (DNL)
Measured by the detection of 13C carbons in chylomicron-palmitate from administered 13C labeled pyruvate or 13C labeled fructose.
Measured: 6 hours
Hepatic (VLDL) fractional de novo lipogenesis (DNL)
Measured by the detection of 13C carbons in VLDL-palmitate from administered 13C labeled pyruvate or 13C labeled fructose.
Measured: 6 hours
Extrasplanchnic fructose
Calculated using total plasma fructose, plasma 2-13C fructose enrichment, and endogenous fructose production
Measured: 6 hours
Whole body fructose oxidation
Measured by 13C atom % excess in exhaled breath, and VCO2 by indirect calorimetry
Measured: 6 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Nov 2019
- Study start15 Sep 2019
- Primary completion31 Dec 2026 (estimated)
- Study completion20 Jul 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Insulin ResistanceStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 35 participants (actual)
Sponsor and investigators
- Lead sponsor
- Touro University, California
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Jean-Marc Schwarz, PhD, Principal investigator, Touro University, California
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04168372
- Sponsor's protocol ID
- M-3018
- Status last verified
- Jul 2026
- First submitted
- 14 Nov 2019
- Last updated
- 10 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 10 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Fructose: Substrate, Stimulus, or Both?
- ClinicalTrials.gov ID
- NCT04168372
- Acronym / sponsor ID
- M-3018
- Conditions
- Insulin Resistance, Insulin Sensitivity, Pre Diabetes
- Keywords
- Fructose, Glucose, Lipogenesis
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 35 participants (actual)
- Lead sponsor
- Touro University, CaliforniaUniversity, hospital or other
- Study start
- 15 Sep 2019 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 20 Jul 2027 (estimated)
- First posted
- 19 Nov 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| High fructose meal, with fructose label | Experimental | Other: High fructose, fructose labeled meal2-13C fructose incorporated into a meal with high fructose content |
| High fructose meal, with pyruvate label | Experimental | Other: High fructose, pyruvate labeled meal2-13C pyruvate incorporated into a meal with high fructose content |
| Low fructose meal, with fructose label | Experimental | Other: Low fructose, fructose labeled meal2-13C fructose incorporated into a meal with low fructose content |
| Low fructose meal, with pyruvate label | Experimental | Other: Low fructose, pyruvate labeled meal2-13C pyruvate incorporated into a meal with low fructose content |
Who may qualify
- Ages
- 20 to 55 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- 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%)
Key exclusion criteria (11 listed)
- 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;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| High fructose, fructose labeled mealLiquid meal containing high fructose (16% of energy), labeled with 2-13C fructose | Other | High fructose meal, with fructose label |
| High fructose, pyruvate labeled mealLiquid meal containing high fructose (16% of energy), labeled with 2-13C pyruvate | Other | High fructose meal, with pyruvate label |
| Low fructose, fructose labeled mealLiquid meals containing low fructose (6% of energy), labeled with 2-13C fructose | Other | Low fructose meal, with fructose label |
| Low fructose, pyruvate labeled mealLiquid meal containing low fructose (6% of energy), labeled with 2-13C pyruvate | Other | Low fructose meal, with pyruvate label |
Primary outcome
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.
Rate of appearance of UDP-glucose
Time frame: 6 hours
An estimate of hepatic glycogen flux measured by administration of D1 galactose and acetaminophen
Rate of appearance of blood glucose from gluconeogenesis
Time frame: 6 hours
Measured by the dilution method of labeled glucose
9 secondary outcomes
Serum triglyceride concentration
Time frame: 6 hours
Serum glucose concentration
Time frame: 6 hours
Serum lactate concentration
Time frame: 6 hours
Serum insulin concentration
Time frame: 6 hours
Serum free fatty acid concentration
Time frame: 6 hours
Enteral (chylomicron) fractional de novo lipogenesis (DNL)
Time frame: 6 hours
Hepatic (VLDL) fractional de novo lipogenesis (DNL)
Time frame: 6 hours
Extrasplanchnic fructose
Time frame: 6 hours
Whole body fructose oxidation
Time frame: 6 hours
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Jul 2026.
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Healthy Volunteer
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Jean-Marc Schwarz, PhD principal investigator
Touro University, California
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing High fructose, fructose labeled meal, High fructose, pyruvate labeled meal and Low fructose, fructose labeled meal in people with Insulin Resistance and Insulin Sensitivity, run by Touro University, California at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 10 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Hepatic fractional de novo lipogenesis in triglyceride rich lipoprotein (TRL) (time frame: 6 hours). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Jul 2026.