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

November 2, 2011 updated by: University Hospital of North Norway

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

160

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Norway
      • Tromsø, Norway, 9037
        • University Hospital of North Norway

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

30 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
intraocular pressure
Time Frame: 6 months
6 months
insulin secretion and sensitivity as assessed by an hyperglycemic clamp
Time Frame: 6 months
6 months

Secondary Outcome Measures

Outcome Measure
Time Frame
telomer length
Time Frame: 6 months
6 months
25-hydroxyvitamin D and 1,25-dihydroxyvitamin D-levels
Time Frame: 6 months
6 months
serum calcium, PTH, phosphate
Time Frame: 6 months
6 months
inflammatory markers and lipids
Time Frame: 6 months
6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University Hospital of North Norway

Collaborators

Norwegian Council on Cardiovascular diseases

Investigators

  • Principal Investigator: Rolf Jorde, Professor, Medical Dpt, University Hospital of Northern Norway

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

November 1, 2008

Primary Completion (Actual)

December 1, 2010

Study Completion (Actual)

December 1, 2010

Study Registration Dates

First Submitted

December 16, 2008

First Submitted That Met QC Criteria

December 16, 2008

First Posted (Estimate)

December 17, 2008

Study Record Updates

Last Update Posted (Estimate)

November 3, 2011

Last Update Submitted That Met QC Criteria

November 2, 2011

Last Verified

November 1, 2011

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • UIT-ENDO-2008-GURI-2

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Intraocular Pressure

Clinical Trials on cholecalciferol

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Togo

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe