InfarctionNCT01395303
Polymorphisms in the Vitamin D System and Health
An observational study of Infarction and Stroke, run by University of Tromso at 1 site in Norway.
Trial summary
Polymorphisms in the vitamin D system appear to affect the serum 25(OH)D levels. If so one would expect these polymorphisms to be associated with vitamin D related conditions and diseases, which will be tested in the present study including DNA analyses in 9700 subjects Read more about this study
- Who is it for?
- Ages 30 to 90 yearsHealthy volunteers can take part
- Conditions the study is for
- Infarction, Stroke, Diabetes
- How many people
- 9,700 participants
- Where
- 1 siteNorway
- Study dates
- Apr 2011to Aug 2016
- 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 30 to 90 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Subjects from the fourth Tromsø study performed in 1994-1995 who had blood samples taken for later DNA analyses
Who may be able to join
- participated in the fourth Tromsø study, later registered in our end point registry or selected as a control subject
Who cannot join
- lacking DNA sample
Trial locations and contacts
1 site in 1 country.
About this study
Polymorphisms in the vitamin D system appear to affect the serum 25(OH)D levels. If so one would expect these polymorphisms to be associated with vitamin D related conditions and diseases, which will be tested in the present study including DNA analyses in 9700 subjects
Read the detailed description
Vitamin D, which is essential in calcium metabolism, is produced in the skin after sun exposure or obtained from food, mainly fatty fish or vitamin D supplements. For activation vitamin D must be hydroxylated in the liver to 25(OH)D and thereafter in the kidney to 1,25(OH)2D. In the circulation 25(OH)D and 1,25(OH)2D are bound to a carrier protein (DBP), and for 1,25(OH)2D to exert its effect it has to bind to the vitamin D receptor (VDR).
The serum level of 25(OH)D, which is the metabolite used to evaluate a person's vitamin D status, is in part genetically determined and several polymorphisms with effects on serum 25(OH)D have been identified. These polymorphisms, where the minor allele frequencies vary between 16 and 40 %, appear as important for the serum 25(OH)D level as the effect of season, physical activity or vitamin D supplementation.
Vitamin D is not only vital for the skeleton, but appears to be related to a number of health outcomes, including mortality as previously demonstrated in the Tromsø study. However, as the serum level of 25(OH)D is strongly influenced by life-style factors that are also related to health outcomes, it is difficult to decide whether the relation between vitamin D and health is causal or not.
On the other hand, the polymorphisms are not influenced by life-style, and the effect of the polymorphisms will be life-long. Accordingly, they may be a better marker of vitamin D status than a single serum 25(OH)D measurement. Furthermore, there are a number of polymorphisms regarding the vitamin D receptor (VDR) that may be associated with health.
In the present study we will therefore relate the polymorphisms affecting the serum 25(OH)D level and the function of the VDR, with anthropometric and biochemical measures, mortality, diseases and risk factors for disease. DNA will be obtained from the 4th Tromsø study.
If we find the expected associations between the polymorphisms and diseases, this will further strengthen the role of vitamin D in human health, and may be important for recommendations regarding vitamin D supplementation. Considering the high prevalence of vitamin D deficiency world wide, this may potentially have huge consequences for public health.
The main purpose of the present study is the vitamin D system, but in the Tromsø study we have previously also found a number of associations between thyroid and androgen function and health. Obtaining DNA for analysis will be the major cost in the project, whereas analyses of individual polymorphisms are relatively cheap. We will therefore also include polymorphisms regarding thyroid and androgen function.
- Conditions
- Infarction, Stroke, Diabetes, Fracture, Aortic Stenosis, Cancer
- Keywords
- infarction, stroke, diabetes, fracture, aortic stenosis, cancer, death, vitamin D, androgens, thyroid hormones
- Medical subject headings
- Infarction, Stroke, Diabetes Mellitus, Fractures, Bone, Aortic Valve Stenosis, Neoplasms, Death
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 |
|---|---|---|
| myocardial infarction | subjects with myocardial infarction in the Tromsø study end point registry | |
| type 2 diabetes | subjects with type 2 diabetes in the Tromsø study end point registry | |
| stroke | subjects with stroke in the Tromsø study end point registry | |
| fracture | subjects with fracture in the Tromsø study end point registry | |
| cancer | subjects with cancer in the Tromsø study end point registry | |
| death | subjects registered as dead in the Tromsø study end point registry | |
| aortic stenosis | subjects with aortic stenosis in the Tromsø study end point registry | |
| control group | randomly selected controls from the Tromsø study |
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Jul 2011 (estimated)
- Study startApr 2011
- Primary completionJul 2016
- Study completionAug 2016
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for InfarctionStudies 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
- Time perspective
- Retrospective
- Enrolment
- 9,700 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Tromso
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Rolf Jorde, University of Tromso
- Investigators
- Rolf Jorde, Professor, Principal investigator, University of Tromso
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01395303
- Sponsor's protocol ID
- UIT-ENDO-2011-2
- Status last verified
- Nov 2016
- First submitted
- 14 Jul 2011
- Last updated
- 11 Nov 2016
- Results posted
- No
- Data monitoring committee
- No
Publications
Jorde R, Schirmer H, Wilsgaard T, Joakimsen RM, Mathiesen EB, Njolstad I, Lochen ML, Figenschau Y, Berg JP, Svartberg J, Grimnes G. Polymorphisms related to the serum 25-hydroxyvitamin D level and risk of myocardial infarction, diabetes, cancer and mortality. The Tromso Study. PLoS One. 2012;7(5):e37295. doi: 10.1371/journal.pone.0037295. Epub 2012 May 23.
PubMed 22649517
Study at a glance
From the registry record, last updated by the sponsor on 11 Nov 2016. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Polymorphisms in the Vitamin D System and Health
- ClinicalTrials.gov ID
- NCT01395303
- Acronym / sponsor ID
- UIT-ENDO-2011-2
- Conditions
- Infarction, Stroke, Diabetes, Fracture, Aortic Stenosis, Cancer
- Keywords
- infarction, stroke, diabetes, fracture, aortic stenosis, cancer, death, vitamin D
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 9,700 participants (actual)
- Lead sponsor
- University of TromsoUniversity, hospital or other
- Study start
- Apr 2011
- Primary completion
- Jul 2016 (actual)
- Study completion
- Aug 2016 (actual)
- First posted
- 15 Jul 2011 (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.
Polymorphisms in the vitamin D system appear to affect the serum 25(OH)D levels. If so one would expect these polymorphisms to be associated with vitamin D related conditions and diseases, which will be tested in the present study including DNA analyses in 9700 subjects
Detailed description
Vitamin D, which is essential in calcium metabolism, is produced in the skin after sun exposure or obtained from food, mainly fatty fish or vitamin D supplements. For activation vitamin D must be hydroxylated in the liver to 25(OH)D and thereafter in the kidney to 1,25(OH)2D. In the circulation 25(OH)D and 1,25(OH)2D are bound to a carrier protein (DBP), and for 1,25(OH)2D to exert its effect it has to bind to the vitamin D receptor (VDR).
The serum level of 25(OH)D, which is the metabolite used to evaluate a person's vitamin D status, is in part genetically determined and several polymorphisms with effects on serum 25(OH)D have been identified. These polymorphisms, where the minor allele frequencies vary between 16 and 40 %, appear as important for the serum 25(OH)D level as the effect of season, physical activity or vitamin D supplementation.
Vitamin D is not only vital for the skeleton, but appears to be related to a number of health outcomes, including mortality as previously demonstrated in the Tromsø study. However, as the serum level of 25(OH)D is strongly influenced by life-style factors that are also related to health outcomes, it is difficult to decide whether the relation between vitamin D and health is causal or not.
On the other hand, the polymorphisms are not influenced by life-style, and the effect of the polymorphisms will be life-long. Accordingly, they may be a better marker of vitamin D status than a single serum 25(OH)D measurement. Furthermore, there are a number of polymorphisms regarding the vitamin D receptor (VDR) that may be associated with health.
In the present study we will therefore relate the polymorphisms affecting the serum 25(OH)D level and the function of the VDR, with anthropometric and biochemical measures, mortality, diseases and risk factors for disease. DNA will be obtained from the 4th Tromsø study.
If we find the expected associations between the polymorphisms and diseases, this will further strengthen the role of vitamin D in human health, and may be important for recommendations regarding vitamin D supplementation. Considering the high prevalence of vitamin D deficiency world wide, this may potentially have huge consequences for public health.
The main purpose of the present study is the vitamin D system, but in the Tromsø study we have previously also found a number of associations between thyroid and androgen function and health. Obtaining DNA for analysis will be the major cost in the project, whereas analyses of individual polymorphisms are relatively cheap. We will therefore also include polymorphisms regarding thyroid and androgen function.
Study design
- Time perspective
- Retrospective
- Number of arms
- 8
| Arm | Type | Receives |
|---|---|---|
| myocardial infarction | – | –subjects with myocardial infarction in the Tromsø study end point registry |
| type 2 diabetes | – | –subjects with type 2 diabetes in the Tromsø study end point registry |
| stroke | – | –subjects with stroke in the Tromsø study end point registry |
| fracture | – | –subjects with fracture in the Tromsø study end point registry |
| cancer | – | –subjects with cancer in the Tromsø study end point registry |
| death | – | –subjects registered as dead in the Tromsø study end point registry |
| aortic stenosis | – | –subjects with aortic stenosis in the Tromsø study end point registry |
| control group | – | –randomly selected controls from the Tromsø study |
Who may qualify
- Ages
- 30 to 90 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Subjects from the fourth Tromsø study performed in 1994-1995 who had blood samples taken for later DNA analyses
Key inclusion criteria (1 listed)
- participated in the fourth Tromsø study, later registered in our end point registry or selected as a control subject
Key exclusion criteria (1 listed)
- lacking DNA sample
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
Not reported in the source record.
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 11 Nov 2016.
- Derived from this study: PubMed 22649517Jorde R, Schirmer H, Wilsgaard T, Joakimsen RM, Mathiesen EB, Njolstad I, Lochen ML, Figenschau Y, Berg JP, Svartberg J, Grimnes G. Polymorphisms related to the serum 25-hydroxyvitamin D level and risk of myocardial infarction, diabetes, cancer and mortality. The Tromso Study. PLoS One. 2012;7(5):e37295. doi: 10.1371/journal.pone.0037295. Epub 2012 May 23.
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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. This study is not recruiting at the moment.
Rolf Jorde, Professor principal investigator
University of Tromso
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 Infarction and Stroke, 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 1 inclusion and 1 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 11 Nov 2016. 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.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01395303, which also lists 1 linked publication.
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 11 Nov 2016.