Impaired Glucose Tolerance
Conditions
Keywords
diabetes, vitamin D, cholecalciferol, glucose tolerance
Brief summary
The prevalence of type 2 diabetes is increasing, which for most societies has considerable consequences not only regarding health but also economy. Type 2 diabetes develops through a prediabetic stage with impaired glucose tolerance. Intervention at this stage with change in lifestyle or with medication may prevent such progression. There are indications that vitamin D is of importance in glucose metabolism, and that supplementation with vitamin D may increase both insulin secretion and insulin sensitivity. Accordingly, supplementation with vitamin D may improve glucose tolerance and potentially prevent the development of type 2 diabetes in subjects at risk. However, this has so far not been demonstrated in a prospective, randomised clinical study. In the present study we will therefore include 600 subjects with impaired glucose tolerance (or impaired fasting glucose) detected in the Tromso study 2007/2008 and randomize to supplementation with vitamin D 20.000IU per week or placebo for 5 years. A glucose tolerance test will be performed each year, and development of type 2 diabetes will be the main endpoint.
Interventions
DRUGPlacebo
Placebo capsule once a week, identical to cholecalciferol capsule
DRUGcholecalciferol
20.000 IU cholecalciferol per week for 5 years versus placebo
Sponsors
University Hospital of North Norway
University of Tromso
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
TRIPLE (Subject, Caregiver, Investigator)
Eligibility
Sex/Gender
ALL
Age
21 Years to 80 Years
Healthy volunteers
Yes
Inclusion criteria
* Impaired glucose tolerance
Exclusion criteria
* Serious heart disease * Renal stone disease * Hypercalcemia * Sarcoidosis
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| development of diabetes type 2 | 5 years |
Secondary
| Measure | Time frame |
|---|---|
| change in glucose metabolism | 5 years |
| change in lipid status | 5 years |
| change in mood | 5 years |
| change in BMD hip | 5 years |
| change in intima media thickness carotid artery | 5 years |
| change in blood pressure | 5 years |
| Change in Insulin sensitivity | 5 years |
| change in HbA1c | 5 years |
| change in weight | 5 years |
| change in telomer length | 5 years |
| change in frequency of infections | 5 years |
Other
| Measure | Time frame | Description |
|---|---|---|
| Oral glucose tolerance response to vitamin D supplementation in relation to polymorphisms in the vitamin D system | 1 year | The response to oral glucose tolerance test (fasting and 2 h blood glucose, serum insulin, C-peptide, measures of insulin resistiance as well as metabolic parameters (lipids, blood pressure)) will be evaluated in the results at the 1-year visit in relation to genetic polymorphisms in the vitamin D system |
Countries
Norway
Outcome results
None listed