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

This study has been completed.
Sponsor:
Collaborator:
Norwegian Council on Cardiovascular diseases
Information provided by (Responsible Party):
University Hospital of North Norway
ClinicalTrials.gov Identifier:
NCT00809744
First received: December 16, 2008
Last updated: November 2, 2011
Last verified: November 2011
History of Changes

December 16, 2008
November 2, 2011
November 2008
December 2010   (final data collection date for primary outcome measure)
  • insulin secretion and sensitivity as assessed by an hyperglycemic clamp [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • intraocular pressure [ Time Frame: 6 months ] [ Designated as safety issue: No ]
Same as current
Complete list of historical versions of study NCT00809744 on ClinicalTrials.gov Archive Site
  • telomer length [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D-levels [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • serum calcium, PTH, phosphate [ Time Frame: 6 months ] [ Designated as safety issue: Yes ]
  • inflammatory markers and lipids [ Time Frame: 6 months ] [ Designated as safety issue: No ]
Same as current
Not Provided
Not Provided
 
Vitamin D AND Glucose Handling Evaluated by Glucose Clamp
Vitamin D AND Cardiovascular Disease

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.
Not Provided
Interventional
Phase 2
Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
  • Insulin Sensitivity
  • Intraocular Pressure
Drug: cholecalciferol
capsules, 20 000IU, twice a week, 6 months duration
Not Provided
Grimnes G, Figenschau Y, Almås 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. Epub 2011 Sep 12.

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Completed
160
December 2010
December 2010   (final data collection date for primary outcome measure)

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
Both
30 Years to 75 Years
No
Contact information is only displayed when the study is recruiting subjects
Norway
 
NCT00809744
UIT-ENDO-2008-GURI-2
No
University Hospital of North Norway
University Hospital of North Norway
Norwegian Council on Cardiovascular diseases
Principal Investigator: Rolf Jorde, Professor Medical Dpt, University Hospital of Northern Norway
University Hospital of North Norway
November 2011

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP