Impaired Glucose ToleranceNCT01771380
Measurement of the Free Fraction of 25-hydroxyvitamin D in Serum
An observational study of Impaired Glucose Tolerance, run by University of Tromso at 1 site in Norway.
Trial summary
In the circulation 25-hydroxyvitaminD (25(OH)D) is bound to the vitamin D binding protein (DBP) and albumin. According to the free hormone hypothesis, it is, however, the free fraction that is biologically active. Polymorphisms in DBP are related to the serum level of 25(OH)D. Read more about this study
- Who is it for?
- Ages 25 to 85 yearsHealthy volunteers can take part
- Conditions the study is for
- Impaired Glucose Tolerance
- How many people
- 78 participants
- Where
- 1 siteNorway
- Study dates
- Feb 2013to Aug 2015
- Phase
- Observational
- Are there results?
- None posted in the registry
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 25 to 85 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Subjects with known impaired glucose tolerance
Who may be able to join
- Impaired glucose tolerance
- living in the Tromsø area
Who cannot join
- pregnancy
- serious illness
Trial locations and contacts
1 site in 1 country.
About this study
In the circulation 25-hydroxyvitaminD (25(OH)D) is bound to the vitamin D binding protein (DBP) and albumin. According to the free hormone hypothesis, it is, however, the free fraction that is biologically active. Polymorphisms in DBP are related to the serum level of 25(OH)D. As these polymorphisms may also affect the binding affinities for 25(OH)D, the total serum 25(OH)D may not necessary reflect the free fraction. To test this hypothesis, we will calculate the free fraction of 25(OH)D by correction for DBP and albumin content, and also measure free 25(OH)D from equilibrium dialysis and ultra filtration. Furthermore, we will relate total serum 25(OH)D as well as the free and biologically active (free- albumin-bound) 25(OH)D to the well established vitamin D effect marker serum parathyroid hormone as well as to the RNA expression in peripheral blood to evaluate the biological importance of the free versus the total fraction of 25(OH)D. We will invite 300 subjects from an ongoing vitamin D supplementation study to participate in the study which will be one visit only and include collection of blood samples.
- Conditions
- Impaired Glucose Tolerance
- Medical subject headings
- Glucose Intolerance
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Subjects with impaired glucose tolerance | Not described |
What is being measured
The primary outcome is the main question the study is designed to answer.
Free fraction of 25(OH)D
Measured: 1 day
Secondary outcomes (1)
DBP polymorphisms
Measured: 1 day
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Jan 2013 (estimated)
- Study startFeb 2013
- Primary completionJun 2015
- Study completionAug 2015
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Impaired Glucose ToleranceStudies 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
- Observational
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Enrolment
- 78 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Tromso
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01771380
- Sponsor's protocol ID
- Tromsø-Endo-2013-1
- Status last verified
- Sep 2015
- First submitted
- 10 Jan 2013
- Last updated
- 22 Sep 2015
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 22 Sep 2015. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Measurement of the Free Fraction of 25-hydroxyvitamin D in Serum
- ClinicalTrials.gov ID
- NCT01771380
- Acronym / sponsor ID
- Tromsø-Endo-2013-1
- Conditions
- Impaired Glucose Tolerance
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 78 participants (actual)
- Lead sponsor
- University of TromsoUniversity, hospital or other
- Study start
- Feb 2013
- Primary completion
- Jun 2015 (actual)
- Study completion
- Aug 2015 (actual)
- First posted
- 18 Jan 2013 (estimated)
- 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.
In the circulation 25-hydroxyvitaminD (25(OH)D) is bound to the vitamin D binding protein (DBP) and albumin. According to the free hormone hypothesis, it is, however, the free fraction that is biologically active. Polymorphisms in DBP are related to the serum level of 25(OH)D. As these polymorphisms may also affect the binding affinities for 25(OH)D, the total serum 25(OH)D may not necessary reflect the free fraction. To test this hypothesis, we will calculate the free fraction of 25(OH)D by correction for DBP and albumin content, and also measure free 25(OH)D from equilibrium dialysis and ultra filtration. Furthermore, we will relate total serum 25(OH)D as well as the free and biologically active (free- albumin-bound) 25(OH)D to the well established vitamin D effect marker serum parathyroid hormone as well as to the RNA expression in peripheral blood to evaluate the biological importance of the free versus the total fraction of 25(OH)D. We will invite 300 subjects from an ongoing vitamin D supplementation study to participate in the study which will be one visit only and include collection of blood samples.
Study design
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Subjects with impaired glucose tolerance | – | – |
Who may qualify
- Ages
- 25 to 85 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Subjects with known impaired glucose tolerance
Key inclusion criteria (2 listed)
- Impaired glucose tolerance
- living in the Tromsø area
Key exclusion criteria (2 listed)
- pregnancy
- serious illness
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Free fraction of 25(OH)D
Time frame: 1 day
1 secondary outcome
DBP polymorphisms
Time frame: 1 day
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Sep 2015.
Related trials for Impaired Glucose Tolerance
Recruiting
Effects of Lean Pork Loin Intake on Protein Homeostasis and Glucose Regulation in Prediabetic Adults
Hyperglycaemia (Non Diabetic), Prediabetes
RecruitingObservational study
Food-i-Sense Analytics: Integrating AI Into Continuous Glucose Monitoring Data Analysis for Precision Nutrition.
Prediabetes (Insulin Resistance, Impaired Glucose Tolerance), Artificial Intelligence Mobile Application
Enrolling by invitationEarly Phase 1
Truway Diagnostic Tools in Primary Care
Chronic Disease, Type 2 Diabetes Mellitus (T2DM), Obesity, Overweight
Recruiting
CGM-Enhanced DPP to Prevent Type 2 Diabetes in Adults With Prediabetes
PreDiabetes
Active, not recruitingPhase 2
Extension Study to Evaluate the Safety of Long-Term Use of Relacorilant in Patients With Cushing Syndrome
Cushing Syndrome
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.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Impaired Glucose Tolerance, run by University of Tromso at 1 site in Norway.
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 2 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: finished, as of the sponsor's last update on 22 Sep 2015. 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 Norway. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Free fraction of 25(OH)D (time frame: 1 day). 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 22 Sep 2015.