Type 1 DiabetesNCT07774780
Oral Galactose as a Substrate for Post-Exercise Skeletal Muscle Glycogen Repletion in Individuals With Type 1 Diabetes
A study testing galactose in people with Type 1 Diabetes, run by University of Aarhus at 2 sites in Denmark.
Trial summary
This Ph.D. project investigates whether orally ingested galactose can be taken up by skeletal muscle and the heart in response to exercise or hyperinsulinemia, and whether it may serve as a viable nutritional strategy for individuals with type 1 diabetes (T1D). Read more about this study
- Who is it for?
- Ages 20 to 70 yearsHealthy volunteers can take part
- Conditions the study is for
- Type 1 Diabetes
- What is being tested?
- galactose
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 16 participants
- Where
- 2 sitesDenmark
- Study dates
- 1 Feb 2027to 31 May 2029
- 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 70 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Healthy or T1D
- BMI 18,5-30 kg/m2
- Singed informed consent
Who cannot join
- Clinically significant heart, lung, kidney, liver, endocrine, or malignant disease based on information collected during the initial screening visit as well as blood tests
- Lack of awareness of hypoglycemia episodes
- Blood donation within the last 3 months
- Smoking
- Alcohol or substance abuse
- Participation in other studies involving ionizing radiation within the last 6 months
- Claustrophobia
- Inability to train one leg for one hour
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Denmark2 sites
Aarhus Universitet
Aarhus, 8000
Ole Fuglsang-Jensen
steno diabetes center Aarhus
Aarhus, 8000
Esben Søndergaard, Professor, +45, esbensoe@rm.dk
About this study
This Ph.D. project investigates whether orally ingested galactose can be taken up by skeletal muscle and the heart in response to exercise or hyperinsulinemia, and whether it may serve as a viable nutritional strategy for individuals with type 1 diabetes (T1D).
Although exercise provides significant health benefits for people with T1D, it is often associated with substantial glucose fluctuations and an increased risk of hypoglycemia. Conventional carbohydrate strategies based on glucose may further exacerbate glycemic instability due to the rapid increase in blood glucose levels. In contrast, galactose is metabolized more slowly and may therefore provide a more stable energy source during and after exercise.
Read more
Previous research has demonstrated that intravenously administered galactose is taken up by human skeletal muscle, with uptake increasing during exercise, suggesting a mechanism that may be at least partly insulin-independent. Building on these findings, this project aims to determine whether similar uptake occurs when galactose is ingested orally.
This study uses a randomized controlled design and applies non-invasive 18F-FDGal PET imaging to quantify galactose uptake in skeletal muscle and cardiac tissue. The findings may contribute to improving dietary recommendations for individuals with T1D, particularly in relation to maintaining stable blood glucose levels during and after physical activity.
Read the detailed description
Previous studies using intravenously administered galactose have demonstrated direct uptake by human skeletal muscle, with uptake increasing following exercise. These findings challenge the traditional view that galactose must first be converted to glucose in the liver before utilization by peripheral tissues and suggest that exercise may stimulate galactose uptake through partly insulin-independent mechanisms. However, it remains unknown whether the tissue distribution and uptake kinetics of orally ingested galactose resemble those observed during intravenous administration.
The primary hypothesis is that prior exercise increases skeletal muscle galactose uptake. A secondary hypothesis is that co-ingestion of glucose reduces peripheral galactose uptake, potentially through increased hepatic extraction.
To investigate this, eight healthy participants and eight individuals with T1D will complete two study days in a randomized crossover design. On each study day, participants will perform 30 minutes of unilateral high-intensity leg exercise, with the non-exercised leg serving as an intra-individual control.
Following exercise, participants will ingest either 30 g galactose or 30 g galactose combined with 30 g glucose together with 100 MBq of ¹⁸F-FDGal. A 90-minute dynamic whole-body PET scan will be performed to characterize the tissue distribution and kinetics of ¹⁸F-FDGal, followed by a static brain scan. Tissue-specific time-activity curves will be extracted and, together with serial blood sampling, used for kinetic modeling of galactose uptake in skeletal muscle, liver, heart, and brain. Blood samples will be collected throughout the experiment to characterize systemic metabolic responses.
The unilateral exercise model enables direct within-participant comparison of galactose uptake between exercised and resting skeletal muscle, while the crossover design allows assessment of how glucose co-ingestion affects galactose distribution and uptake.
- Conditions
- Type 1 Diabetes
- Being tested
- galactose
- Keywords
- Galactose metabolism, Skeletal muscle uptake of Galactose, Hepatic galactose uptake, Cerebral galactose uptake
- Medical subject headings
- Diabetes Mellitus, Type 1
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
galactoseDietary supplement
Also called Galactose + glucose
Participants undergo two experimental conditions in a randomized crossover design. In one condition, participants ingest 30 g of galactose, whereas in the other condition, they ingest 30 g of galactose combined with 30 g of glucose. The order of the conditions is randomized across participants.
| Study group | Role | What they receive |
|---|---|---|
| Galactose | Experimental | The patient will orally ingest 30 g of galactose. Receives: Dietary Supplement: galactose |
| Galactose + Glucose | Active comparator | The patient will orally ingest 30 g of galactose and 30 g of glucose. Receives: Dietary Supplement: galactose |
What is being measured
The primary outcome is the main question the study is designed to answer.
Skeletal muscle galactose uptake rate (μmol/min/g) measured by 2-(18)F-fluoro-2-deoxy-d-galactose (18F-FDGal)
Measured: Measurement will be made on each of the two study days
Secondary outcomes (2)
Hepatic galactose uptake
Hepatic galactose uptake rate (μmol/min/g) measured by 2-(18)F-fluoro-2-deoxy-d-galactose (18F-FDGal)
Measured: Measurements will be made on each of the two study days
Cerebral galactose Uptake
Galactose uptake in the brain, measured by a 10-minute static PET-CT scan performed after the 90-minute dynamic scan.
Measured: Measurement will be made on each of the two study days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Aug 2026
- Study start1 Feb 2027 (estimated)
- Primary completionSep 2028 (estimated)
- Study completion31 May 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Type 1 DiabetesStudies 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
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Participants will complete two experimental study visits in a randomized crossover design. On one visit, participants will ingest 30 g galactose, and on the other visit they will ingest 30 g galactose combined with 30 g glucose. The order of the interventions will be randomized. At each visit, participants will perform a 30-minute one-legged exercise protocol, consisting of a 5-minute warm-up followed by repeated 1-minute high-intensity intervals interspersed with 2-minute recovery periods. Immediately after exercise, participants will consume the assigned carbohydrate beverage together with approximately 100 MBq 18F-FDGal dissolved in water. After ingestion, participants will undergo a 90-minute dynamic whole-body PET scan to assess galactose uptake in skeletal muscle and extra-hepatic organs. Following a short break, a 10-minute static brain PET scan will be performed to evaluate cerebral tracer uptake.
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 16 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Aarhus
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ole Fuglsang-Jensen, University of Aarhus
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07774780
- Sponsor's protocol ID
- 1-10-72-25-26
- Other IDs
- 1-10-72-25-26
- Status last verified
- Aug 2026
- First submitted
- 10 Aug 2026
- Last updated
- 19 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 19 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Oral Galactose as a Substrate for Post-Exercise Skeletal Muscle Glycogen Repletion in Individuals With Type 1 Diabetes
- ClinicalTrials.gov ID
- NCT07774780
- Acronym / sponsor ID
- 1-10-72-25-26
- Conditions
- Type 1 Diabetes
- Keywords
- Galactose metabolism, Skeletal muscle uptake of Galactose, Hepatic galactose uptake, Cerebral galactose uptake
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 16 participants (estimated)
- Lead sponsor
- University of AarhusUniversity, hospital or other
- Study start
- 1 Feb 2027 (estimated)
- Primary completion
- Sep 2028 (estimated)
- Study completion
- 31 May 2029 (estimated)
- First posted
- 19 Aug 2026 (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 Ph.D. project investigates whether orally ingested galactose can be taken up by skeletal muscle and the heart in response to exercise or hyperinsulinemia, and whether it may serve as a viable nutritional strategy for individuals with type 1 diabetes (T1D).
Although exercise provides significant health benefits for people with T1D, it is often associated with substantial glucose fluctuations and an increased risk of hypoglycemia. Conventional carbohydrate strategies based on glucose may further exacerbate glycemic instability due to the rapid increase in blood glucose levels. In contrast, galactose is metabolized more slowly and may therefore provide a more stable energy source during and after exercise.
Previous research has demonstrated that intravenously administered galactose is taken up by human skeletal muscle, with uptake increasing during exercise, suggesting a mechanism that may be at least partly insulin-independent. Building on these findings, this project aims to determine whether similar uptake occurs when galactose is ingested orally.
This study uses a randomized controlled design and applies non-invasive 18F-FDGal PET imaging to quantify galactose uptake in skeletal muscle and cardiac tissue. The findings may contribute to improving dietary recommendations for individuals with T1D, particularly in relation to maintaining stable blood glucose levels during and after physical activity.
Detailed description
Previous studies using intravenously administered galactose have demonstrated direct uptake by human skeletal muscle, with uptake increasing following exercise. These findings challenge the traditional view that galactose must first be converted to glucose in the liver before utilization by peripheral tissues and suggest that exercise may stimulate galactose uptake through partly insulin-independent mechanisms. However, it remains unknown whether the tissue distribution and uptake kinetics of orally ingested galactose resemble those observed during intravenous administration.
The primary hypothesis is that prior exercise increases skeletal muscle galactose uptake. A secondary hypothesis is that co-ingestion of glucose reduces peripheral galactose uptake, potentially through increased hepatic extraction.
To investigate this, eight healthy participants and eight individuals with T1D will complete two study days in a randomized crossover design. On each study day, participants will perform 30 minutes of unilateral high-intensity leg exercise, with the non-exercised leg serving as an intra-individual control.
Following exercise, participants will ingest either 30 g galactose or 30 g galactose combined with 30 g glucose together with 100 MBq of ¹⁸F-FDGal. A 90-minute dynamic whole-body PET scan will be performed to characterize the tissue distribution and kinetics of ¹⁸F-FDGal, followed by a static brain scan. Tissue-specific time-activity curves will be extracted and, together with serial blood sampling, used for kinetic modeling of galactose uptake in skeletal muscle, liver, heart, and brain. Blood samples will be collected throughout the experiment to characterize systemic metabolic responses.
The unilateral exercise model enables direct within-participant comparison of galactose uptake between exercised and resting skeletal muscle, while the crossover design allows assessment of how glucose co-ingestion affects galactose distribution and uptake.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 2
- Model description
- Participants will complete two experimental study visits in a randomized crossover design. On one visit, participants will ingest 30 g galactose, and on the other visit they will ingest 30 g galactose combined with 30 g glucose. The order of the interventions will be randomized. At each visit, participants will perform a 30-minute one-legged exercise protocol, consisting of a 5-minute warm-up followed by repeated 1-minute high-intensity intervals interspersed with 2-minute recovery periods. Immediately after exercise, participants will consume the assigned carbohydrate beverage together with approximately 100 MBq 18F-FDGal dissolved in water. After ingestion, participants will undergo a 90-minute dynamic whole-body PET scan to assess galactose uptake in skeletal muscle and extra-hepatic organs. Following a short break, a 10-minute static brain PET scan will be performed to evaluate cerebral tracer uptake.
| Arm | Type | Receives |
|---|---|---|
| Galactose | Experimental | Dietary Supplement: galactoseThe patient will orally ingest 30 g of galactose. |
| Galactose + Glucose | Active comparator | Dietary Supplement: galactoseThe patient will orally ingest 30 g of galactose and 30 g of glucose. |
Who may qualify
- Ages
- 20 to 70 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Healthy or T1D
- BMI 18,5-30 kg/m2
- Singed informed consent
Key exclusion criteria (8 listed)
- Clinically significant heart, lung, kidney, liver, endocrine, or malignant disease based on information collected during the initial screening visit as well as blood tests
- Lack of awareness of hypoglycemia episodes
- Blood donation within the last 3 months
- Smoking
- Alcohol or substance abuse
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 |
|---|---|---|
| galactoseAlso: Galactose + glucoseParticipants undergo two experimental conditions in a randomized crossover design. In one condition, participants ingest 30 g of galactose, whereas in the other condition, they ingest 30 g of galactose combined with 30 g of glucose. The order of the conditions is randomized across participants. | Dietary supplement | Galactose, Galactose + Glucose |
Primary outcome
Skeletal muscle galactose uptake rate (μmol/min/g) measured by 2-(18)F-fluoro-2-deoxy-d-galactose (18F-FDGal)
Time frame: Measurement will be made on each of the two study days
2 secondary outcomes
Hepatic galactose uptake
Time frame: Measurements will be made on each of the two study days
Cerebral galactose Uptake
Time frame: Measurement will be made on each of the two study days
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 19 Aug 2026.
- Individual participant dataSharing planned: No
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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.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing galactose in people with Type 1 Diabetes, run by University of Aarhus at 2 sites in Denmark.
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 3 inclusion and 8 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: opening soon, as of the sponsor's last update on 19 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Denmark. 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?
Contact Ole Fuglsang-Jensen, master in sports science (+4527897650, AU664914@uni.au.dk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Skeletal muscle galactose uptake rate (μmol/min/g) measured by 2-(18)F-fluoro-2-deoxy-d-galactose (18F-FDGal) (time frame: Measurement will be made on each of the two study days). 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 19 Aug 2026.