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Vitamin D AND Glucose Handling Evaluated by Glucose Clamp (D-clamp)

Primary Purpose

Insulin Sensitivity, Intraocular Pressure

Status
Completed
Phase
Phase 2
Locations
Norway
Study Type
Interventional
Intervention
cholecalciferol
Sponsored by
University Hospital of North Norway
About
Eligibility
Locations
Outcomes
Full info

About this trial

This is an interventional basic science trial for Insulin Sensitivity

Eligibility Criteria

30 Years - 75 Years (Adult, Older Adult)All SexesDoes not accept healthy volunteers

Inclusion Criteria:

  • generally: Subjects are recruited from the 6th Tromsø Study
  • cases: serum 25-hydroxyvitamin D-levels below the 10 percentile; low levels confirmed with new serum analyses.
  • controls: serum 25-hydroxyvitamin D levels 80-95 percentile, normal-high levels confirmed with new serum analyses.

Exclusion Criteria:

  • diabetes
  • myocardial infarction or apoplexia
  • active cancer during last 5 years
  • history of kidney stone
  • pregnancy or premenopausal without safe anticonception
  • primary hyperparathyroidism
  • systolic blood pressure >175 or diastolic blood pressure >105

Sites / Locations

  • University Hospital of North Norway

Outcomes

Primary Outcome Measures

insulin secretion and sensitivity as assessed by an hyperglycemic clamp
intraocular pressure

Secondary Outcome Measures

telomer length
25-hydroxyvitamin D and 1,25-dihydroxyvitamin D-levels
serum calcium, PTH, phosphate
inflammatory markers and lipids

Full Information

First Posted
December 16, 2008
Last Updated
November 2, 2011
Sponsor
University Hospital of North Norway
Collaborators
Norwegian Council on Cardiovascular diseases
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1. Study Identification

Unique Protocol Identification Number
NCT00809744
Brief Title
Vitamin D AND Glucose Handling Evaluated by Glucose Clamp
Acronym
D-clamp
Official Title
Vitamin D AND Cardiovascular Disease
Study Type
Interventional

2. Study Status

Record Verification Date
November 2011
Overall Recruitment Status
Completed
Study Start Date
November 2008 (undefined)
Primary Completion Date
December 2010 (Actual)
Study Completion Date
December 2010 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor
Name of the Sponsor
University Hospital of North Norway
Collaborators
Norwegian Council on Cardiovascular diseases

4. Oversight

Data Monitoring Committee
No

5. Study Description

Brief Summary
In this study the investigators want to compare glucose handling (insulin secretion and insulin sensitivity) in 100 persons with low and 50 persons with normal-high levels of vitamin D, using a hyperglycemic clamp technique, were sugar is given intravenously for 3 hours in order to keep the blood sugar level at 10 mmol/L. Those with low vitamin D levels will be randomized to treatment with vitamin D3 (cholecalciferol) 40 000 IU/week or placebo for 6 months before a new clamp is performed. The study hypothesis is that persons with low vitamin D levels have impaired glucose handling which might be improved by vitamin D supplementation.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Insulin Sensitivity, Intraocular Pressure

7. Study Design

Primary Purpose
Basic Science
Study Phase
Phase 2
Interventional Study Model
Parallel Assignment
Masking
ParticipantCare ProviderInvestigatorOutcomes Assessor
Allocation
Randomized
Enrollment
160 (Actual)

8. Arms, Groups, and Interventions

Intervention Type
Drug
Intervention Name(s)
cholecalciferol
Intervention Description
capsules, 20 000IU, twice a week, 6 months duration
Primary Outcome Measure Information:
Title
insulin secretion and sensitivity as assessed by an hyperglycemic clamp
Time Frame
6 months
Title
intraocular pressure
Time Frame
6 months
Secondary Outcome Measure Information:
Title
telomer length
Time Frame
6 months
Title
25-hydroxyvitamin D and 1,25-dihydroxyvitamin D-levels
Time Frame
6 months
Title
serum calcium, PTH, phosphate
Time Frame
6 months
Title
inflammatory markers and lipids
Time Frame
6 months

10. Eligibility

Sex
All
Minimum Age & Unit of Time
30 Years
Maximum Age & Unit of Time
75 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria: generally: Subjects are recruited from the 6th Tromsø Study cases: serum 25-hydroxyvitamin D-levels below the 10 percentile; low levels confirmed with new serum analyses. controls: serum 25-hydroxyvitamin D levels 80-95 percentile, normal-high levels confirmed with new serum analyses. Exclusion Criteria: diabetes myocardial infarction or apoplexia active cancer during last 5 years history of kidney stone pregnancy or premenopausal without safe anticonception primary hyperparathyroidism systolic blood pressure >175 or diastolic blood pressure >105
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Rolf Jorde, Professor
Organizational Affiliation
Medical Dpt, University Hospital of Northern Norway
Official's Role
Principal Investigator
Facility Information:
Facility Name
University Hospital of North Norway
City
Tromsø
ZIP/Postal Code
9037
Country
Norway

12. IPD Sharing Statement

Citations:
PubMed Identifier
21911741
Citation
Grimnes G, Figenschau Y, Almas B, Jorde R. Vitamin D, insulin secretion, sensitivity, and lipids: results from a case-control study and a randomized controlled trial using hyperglycemic clamp technique. Diabetes. 2011 Nov;60(11):2748-57. doi: 10.2337/db11-0650. Epub 2011 Sep 12.
Results Reference
derived

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Vitamin D AND Glucose Handling Evaluated by Glucose Clamp

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