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Effect of Vitamin D3 Supplementation on Insulin Resistance- The DIR Study

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ClinicalTrials.gov Identifier: NCT01889810
Recruitment Status : Completed
First Posted : June 28, 2013
Last Update Posted : July 11, 2016
Sponsor:
Collaborators:
HSC Research & Development Division, Public Health Agency, Northern Ireland
The Metabolic Unit Research Fund, The Royal Hospitals, Belfast, Northern Ireland
NI Chest, Heart & Stroke
Information provided by (Responsible Party):
Michelle McKinley, Queen's University, Belfast

Brief Summary:

Insulin resistance is a state where the body does not respond as it should to the insulin it produces. Individuals who are insulin resistant are at increased risk of both heart disease and type 2 diabetes; importantly, diabetes more than doubles the risk of heart disease, independent of other recognised risk factors. Interventions that prevent or reverse insulin resistance may help to attenuate risk of heart disease and diabetes. A number of randomised controlled trials provide proof of concept evidence regarding a beneficial effect of vitamin D on insulin resistance and other cardiovascular risk markers but experts have stated that further studies are required. Importantly, these studies should use appropriate endpoints, provide a high enough dose of vitamin D to optimise vitamin D status, and they should be conducted in clearly defined populations, The vitamin D trial we propose addresses these issues and aims to evaluate a potentially straightforward and low cost health care intervention for populations at highrisk of heart disease and diabetes. Specifically, this study would provide clinically relevant information on the metabolic effects of optimising vitamin D status in these high risk patients. This has clear economic and social implications given the current, and projected, burden of heart disease and diabetes.

This study will investigate the effect of vitamin D3 supplementation on insulin resistance and cardiovascular risk factors in people at high risk of type 2 diabetes and cardiovascular disease using the gold standard euglycaemic hyperinsulinaemic clamp method.


Condition or disease Intervention/treatment Phase
Sub-optimal Vitamin D Status Pre-diabetes Insulin Resistance Dietary Supplement: Vitamin D3 supplementation Not Applicable

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 81 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
Official Title: Effect of Vitamin D3 Supplementation on Insulin Resistance and Cardiovascular Risk Factors in People at High Risk of Type 2 Diabetes and Cardiovascular Disease (The DIR Study)
Study Start Date : August 2013
Actual Primary Completion Date : June 2016
Actual Study Completion Date : June 2016

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Vitamin D

Arm Intervention/treatment
Active Comparator: Vitamin D3 supplementation
Patients will take 3000IU (75 µg) Vitamin D3 supplementation per day for a period of 26 weeks.
Dietary Supplement: Vitamin D3 supplementation
3000IU (75µg) vitamin D3 will be given daily for a period of 26 weeks to the group who receive the active comparator. The efficacy of vitamin D3 supplementation on insulin resistance will be compared to the placebo group.

Placebo Comparator: Placebo
Placebo group
Dietary Supplement: Vitamin D3 supplementation
3000IU (75µg) vitamin D3 will be given daily for a period of 26 weeks to the group who receive the active comparator. The efficacy of vitamin D3 supplementation on insulin resistance will be compared to the placebo group.




Primary Outcome Measures :
  1. Change in Insulin Resistance [ Time Frame: Measured at baseline and after 6 months ]
    Insulin resistance will be measured using the gold standard euglycaemic-hyperinsulinaemic clamp method (note - it is anticipated that a total of 60 volunteers will complete the primary endpoint assessment).


Secondary Outcome Measures :
  1. Change in vitamin D status [ Time Frame: Measured at baseline and after 6 months ]
    Change in vitamin D status will be measured using the gold standard Ultra performance liquid chromatography followed by tandem mass spectrometry

  2. Change in markers of cardiovascular risk [ Time Frame: Measured at baseline and after 6 months ]
    Measurements of seated and 24-hour ambulatory blood pressure, lipids, homeostasis model assessment (HOMA), HbA1c, and inflammatory and immune function markers including tumour necrosis factor-alpha and high sensitivity c-reactive protein

  3. Change in carotid-femoral pulse wave velocity (PWV) [ Time Frame: Measured at baseline and after 6 months ]
    Assessed by sequential tonometry with ECG gating using the SphygmoCor PWV System

  4. Change in hand grip strength [ Time Frame: Measured at baseline and after 6 months ]
    Assessed using hand held dynamometer

  5. Health status [ Time Frame: Measured at baseline and after 6 months ]
    SF-36 Questionnaire



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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Impaired glucose tolerance (Fasting glucose <7.0 mmol/L (126mg/dl) and 2hr post-glucose load 7.8-11.0 mmol/L (140-199 mg/dl) or Impaired fasting glucose 5.6-6.9 mmol/L (100-125mg/dL) defined according to American Diabetes Association
  • Sub-optimal vitamin D status (<50nmol/L)

Exclusion Criteria:

  • Diabetes mellitus
  • Established cardiovascular disease
  • Psychiatric problems
  • Pregnant or lactating
  • Medical conditions or dietary restrictions that would substantially limit ability to complete the study requirements
  • Excessive alcohol consumption (>28 Units/week men or >21 Units/week women)
  • Already taking vitamin D supplements > 10 µg/d
  • Medical conditions or medications that could influence vitamin D metabolism
  • History of kidney stones
  • Hypercalcaemia
  • Hyperparathyroidism
  • Significant liver and renal disease (liver function tests >3x upper limit of normal and glomerular filtration rate <30ml/min)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01889810


Locations
United Kingdom
Queen's University, Belfast
Belfast, N. Ireland, United Kingdom, BT12 6BJ
Sponsors and Collaborators
Queen's University, Belfast
HSC Research & Development Division, Public Health Agency, Northern Ireland
The Metabolic Unit Research Fund, The Royal Hospitals, Belfast, Northern Ireland
NI Chest, Heart & Stroke
Investigators
Principal Investigator: Michelle McKinley, PhD Queen's University, Belfast

Responsible Party: Michelle McKinley, Senior Lecturer, Nutrition & Metabolism Research Group, Centre for Public Health, Queen's University, Belfast
ClinicalTrials.gov Identifier: NCT01889810     History of Changes
Other Study ID Numbers: QUB: B12/35; HSC: 12117MMcK-AS
First Posted: June 28, 2013    Key Record Dates
Last Update Posted: July 11, 2016
Last Verified: July 2016

Keywords provided by Michelle McKinley, Queen's University, Belfast:
Vitamin D, Pre-diabetes, Insulin Resistance

Additional relevant MeSH terms:
Insulin Resistance
Prediabetic State
Glucose Intolerance
Hyperinsulinism
Glucose Metabolism Disorders
Metabolic Diseases
Diabetes Mellitus
Endocrine System Diseases
Hyperglycemia
Insulin, Globin Zinc
Insulin
Vitamins
Vitamin D
Ergocalciferols
Cholecalciferol
Hypoglycemic Agents
Physiological Effects of Drugs
Micronutrients
Growth Substances
Bone Density Conservation Agents