Does Vitamin D improve markers of vascular health in type 2 diabetes?

ISRCTN	ISRCTN46424296
DOI	https://doi.org/10.1186/ISRCTN46424296
Secondary identifying numbers	JUS004

Submission date: 26/07/2005
Registration date: 12/09/2005
Last edited: 29/08/2017

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Nutritional, Metabolic, Endocrine

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English summary of protocol

Background and study aims
Low levels of vitamin D have been associated with higher blood pressure and a higher risk of heart attack and stroke. These are particular problems for people with diabetes, and it is possible that giving extra vitamin D to people with diabetes who have low vitamin D levels might help to protect against heart attacks and strokes. The aim of this study is to find out whether giving vitamin D can reduce blood pressure, improve measures of blood vessel health, and improve glucose levels in diabetes.

Who can participate?
Patients aged over 18 with type 2 diabetes and low levels of vitamin D

What does the study involve?
Participants' vitamin D levels are tested and if these are low, the health of their blood vessels is assessed by doing an ultrasound scan of their arm before and after blowing up a blood pressure cuff on their arm. Blood samples are also taken to measure a series of substances that vitamin D might affect, and their blood pressure is measured. Participants are then randomly allocated take either a single large dose of vitamin D or a matching dummy (placebo) dose with no vitamin D in it. This dose acts over a period of several weeks. All participants are asked to return to repeat all of the tests 8 weeks after this single dose.

What are the possible benefits and risks of participating?
Vitamin D is a safe treatment that has been used for decades. There is a small risk of increasing calcium levels in the blood, but these levels are monitored and anyone with high levels at the start of the study is not included.

Where is the study run from?
Ninewells Hospital (UK)

When is the study starting and how long is it expected to run for?
October 2005 to June 2006

Who is funding the study?
Diabetes UK

Who is the main contact?
Dr Justine Davies
j.i.davies@dundee.ac.uk

Contact information

Dr Justine Davies
Scientific

Dept of Clinical Pharmacology
Ninewells Hospital
Dundee
DD1 9SY
United Kingdom

Phone	+44 (0)1382 632180
Email	j.i.davies@dundee.ac.uk

Study information

Study design	Randomised controlled trial
Primary study design	Interventional
Secondary study design	Randomised controlled trial
Study setting(s)	Hospital
Study type	Treatment
Participant information sheet	Not available in web format, please use the contact details to request a patient information sheet
Scientific title	Does Vitamin D improve markers of vascular health in type 2 diabetes? A randomised controlled trial
Study objectives	That Vitamin D improves endothelial function, pulse wave velocity, insulin sensitivity and markers of renin-angiotensin system activation in type 2 diabetics.
Ethics approval(s)	Tayside (now East of Scotland) Research Ethics committee, 13/09/2005, ref: 05/S1401/125
Health condition(s) or problem(s) studied	Type 2 diabetes mellitus
Intervention	100,000 units ergocalciferol versus placebo Added 29/08/2017: Intervention: 100,000 units oral Ergocalciferol (vitamin D2), given once at baseline Comparator: Matching placebo, given once at baseline Total duration of treatment and follow-up: 8 weeks for all treatment arms
Intervention type	Supplement
Primary outcome measure	Current primary outcome measures as of 29/08/2017: Flow-mediated dilatation of the brachial artery in response to reactive hyperaemia, measured by ultrasound at baseline and 8 weeks Previous primary outcome measures: Change in flow mediated dilatation of the brachial artery
Secondary outcome measures	Current secondary outcome measures as of 29/08/2017: 1. 25-hydroxyvitamin D, serum calcium, serum phosphate, parathyroid hormone levels, measured by blood tests at baseline and 8 weeks 2. Glycosylated haemoglobin, insulin sensitivity using HOMA index, measured by blood tests at baseline and 8 weeks 3. Office blood pressure, measured by blood pressure cuff at baseline and 8 weeks 4. Renin and angiotensin levels, measured by blood tests at baseline and 8 weeks Previous secondary outcome measures: Pulse wave velocity, homeostasis model assessment (HOMA) index, renin, angiotensin, Vitamin D, parathyroid hormone (PTH)
Overall study start date	01/10/2005
Completion date	30/06/2006

Eligibility

Participant type(s)	Patient
Age group	Adult
Lower age limit	18 Years
Sex	Both
Target number of participants	60
Key inclusion criteria	1. Age ≥18 years 2. Vitamin D level <50 nmol/l
Key exclusion criteria	1. Serum creatinine >200 µmol/l 2. Liver function tests >3 x upper limit of normal 3. Corrected calcium >2.55 mmol/l or <2.15 mmol/l 4. Metastatic malignancy 5. Unable to give informed consent
Date of first enrolment	01/11/2005
Date of final enrolment	31/03/2006

Locations

Countries of recruitment

Scotland
United Kingdom

Study participating centre

Ninewells Hospital

Dundee
DD1 9SY
United Kingdom

Sponsor information

University of Dundee (UK)
University/education

11 Perth Road
Dundee
DD1 4HN
Scotland
United Kingdom

Phone	+44 (0)1382 344664
Email	j.z.houston@dundee.ac.uk
"ROR"	https://ror.org/03h2bxq36

Funders

Funder type

Charity

Diabetes UK
Private sector organisation / Trusts, charities, foundations (both public and private)

Alternative name(s): DIABETES UK LIMITED, British Diabetic Association
Location: United Kingdom

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to share	Yes
IPD sharing plan summary	Available on request
Publication and dissemination plan	Not provided at time of registration
IPD sharing plan	The datasets generated during and/or analysed during the current study are available upon request from Dr Miles Witham (m.witham@dundee.ac.uk). Anonymised Individual participant data on all those randomised will be made available to bona fide researchers for non-commercial use, subject to sight of an analysis plan and subject to appropriate data sharing agreements and approval from the trial sponsor.

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Results article	results	01/03/2008		Yes	No
Basic results		18/08/2017	29/08/2017	No	No

Additional files

ISRCTN46424296_BasicResults_18Aug17.pdf: Uploaded 29/08/2017

Editorial Notes

29/08/2017: Ethics approval, interventions and outcome measures details added, plain English summary added. The basic results of this trial have been uploaded as an additional file.
18/08/2017: Recruitment dates and IPD sharing statement added.