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

This study is currently recruiting participants. (see Contacts and Locations)
Verified November 2013 by Queen's University, Belfast
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
ClinicalTrials.gov Identifier:
NCT01889810
First received: June 26, 2013
Last updated: November 26, 2013
Last verified: November 2013
  Purpose

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 Intervention
Sub-optimal Vitamin D Status
Pre-diabetes
Insulin Resistance
Dietary Supplement: Vitamin D3 supplementation

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, 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)

Resource links provided by NLM:


Further study details as provided by Queen's University, Belfast:

Primary Outcome Measures:
  • Change in Insulin Resistance [ Time Frame: Measured at baseline and after 6 months ] [ Designated as safety issue: No ]
    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:
  • Change in vitamin D status [ Time Frame: Measured at baseline and after 6 months ] [ Designated as safety issue: No ]
    Change in vitamin D status will be measured using the gold standard Ultra performance liquid chromatography followed by tandem mass spectrometry

  • Change in markers of cardiovascular risk [ Time Frame: Measured at baseline and after 6 months ] [ Designated as safety issue: No ]
    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

  • Change in carotid-femoral pulse wave velocity (PWV) [ Time Frame: Measured at baseline and after 6 months ] [ Designated as safety issue: No ]
    Assessed by sequential tonometry with ECG gating using the SphygmoCor PWV System


Estimated Enrollment: 94
Study Start Date: August 2013
Estimated Study Completion Date: July 2016
Estimated Primary Completion Date: July 2016 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
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)
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01889810

Contacts
Contact: Michelle McKinley, PhD 02890632685 m.mckinley@qub.ac.uk
Contact: Steven J Hunter, MD 02890471883 steven.hunter@belfasttrust.hscni.net

Locations
United Kingdom
Queen's University, Belfast Recruiting
Belfast, N. Ireland, United Kingdom, BT12 6BJ
Contact: Michelle McKinley, PhD    02890632685    m.mckinley@qub.ac.uk   
Contact: Steven J Hunter, MD    02890471883    steven.hunter@belfasttrust.hscni.net   
Sub-Investigator: Steven J Hunter, MD         
Principal Investigator: Michelle McKinley, PhD         
Sub-Investigator: Ian Young, MD         
Sub-Investigator: Helen J Wallace, MB         
Sub-Investigator: Lauren Holmes, BSc(Hons)         
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
  More Information

No publications provided

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
Study First Received: June 26, 2013
Last Updated: November 26, 2013
Health Authority: United Kingdom: Research Ethics Committee

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

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

ClinicalTrials.gov processed this record on July 22, 2014