Does vitamin D improve markers of vascular health in stroke patients?

ISRCTN ISRCTN28737567
DOI https://doi.org/10.1186/ISRCTN28737567
Secondary identifying numbers Res/A107
Submission date
21/02/2007
Registration date
01/05/2007
Last edited
26/02/2018
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Circulatory System
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Background and study aims
Small studies have shown that vitamin D, a hormone that the skin usually makes using sunshine, may be able to reduce blood pressure and improve blood vessel health in some people. People who have had a stroke very often have low vitamin D levels, and people with low vitamin D tend to have higher blood pressure. People with high blood pressure have blood vessels that do not work as well as normal, and this leads to a higher risk of heart problems and strokes.
The aim of the study is therefore to test whether giving extra vitamin D to people who have had a stroke in the past helps to reduce blood pressure and improve other measures of blood vessel and heart health.

Who can participate?
Adults aged 18 years and over who have had a stroke

What does the study involve?
The study lasts for 16 weeks. Participants are randomly allocated to one of two groups, and given either a single capsule of vitamin D or a matching placebo (dummy) tablet.
Participants are assessed at the start, and 8 weeks and 16 weeks, with each visit lasting 1.5 hours.
At each visit, participants receive some or all of the following depending on which visit it is:
- Blood pressure measured
- Blood sample taken
- Test the function of the artery in their arm. The artery is scanned with an ultrasound machine before and after inflating a blood pressure cuff on their forearm for 5 minutes. The test is repeated after giving the participant a medication (GTN) spray under their tongue.
- Wear a blood pressure cuff and a heart rate monitor (ECG) for 24 hours including at home

What are the possible benefits and risks of participating?
Although participants are unlikely to benefit directly by taking part in the trial, those who receive the vitamin D might find that blood pressure is lower.
Although this dose of vitamin D has been used before and is known to be safe there is a small possibility of side effects. Participants are closely monitored for side effects caused by high calcium levels: sickness, diarrhoea, thirst or dizziness. To reduce the chance of vitamin D increasing the calcium level in their blood, participants are also asked not to take vitamin D supplements or calcium supplements whilst taking part in this study.
Having blood taken can cause some bruising. The blood pressure cuff causes mild discomfort to some people.

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

When is the study starting and how long is it expected to run for?
September 2006 to May 2009

Who is funding the study?
Chest Heart and Stroke Scotland (UK)

Who is the main contact?
Dr Miles Witham (Scientific)
m.witham@dundee.ac.uk

Contact information

Dr Miles Witham
Scientific

Department of Medicine & Therapeutics
University of Dundee
Ninewells Hospital & Medical School
Dundee
DD1 9SY
United Kingdom

Phone +44 (0)1382 632436
Email m.witham@dundee.ac.uk

Study information

Study designDouble blind randomised placebo controlled trial.
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Hospital
Study typeTreatment
Participant information sheet Not available in web format, please use the contact details below to request a patient information sheet
Scientific titleThe effect of vitamin D replacement on markers of vascular health in stroke patients - a randomised controlled trial
Study objectivesThat a single dose of oral vitamin D can lower blood pressure and improve endothelial function in stroke patients
Ethics approval(s)Tayside Local Research Ethics Committee,14/05/200, ref: 07/S1401/41
Health condition(s) or problem(s) studiedStroke
InterventionA single oral dose of 100,000 U ergocalciferol (vitamin D) or placebo.
Intervention typeOther
Primary outcome measureBlood pressure (seated office and 24 hour measurements) (added 26/02/2018: measured using a blood pressure cuff) at baseline, 8 and 16 weeks after vitamin D administration.
Secondary outcome measuresCurrent secondary outcome measures (as of 26/02/2018):
All outcomes are measured at baseline, and 8 and 16 weeks after vitamin D administration:
1. Endothelial function of the artery in the arm is measured using ultrasound following an inflated blood pressure cuff
2. B-type natriuretic peptide is measured from a blood sample
3. Heart rate variability is measured using a 24 hour ECG
4. Vitamin D deficiency is measured using 25OHD

Previous secondary outcome measures;
The secondary outcomes will also be measured at baseline and then at 8 and 16 weeks after vitamin D administration.

1. Endothelial function
2. B-type natriuretic peptide
3. Heart rate variability
Overall study start date30/09/2006
Completion date31/05/2009

Eligibility

Participant type(s)Patient
Age groupAdult
SexBoth
Target number of participants68 (two groups of 34)
Key inclusion criteria1. Clinical diagnosis of completed stroke (ischaemic or haemorrhagic)
2. Serum 25-hydroxy vitamin D level less than 50 nmol/L
Key exclusion criteria1. Hyper- or hypocalcaemia
2. Metastatic malignancy
3. Liver function tests over three times limit of normal
4. Estimated glomerular filtration rate (GFR) less than 40 ml/min
5. Previous clinical diagnosis of osteomalacia
6. Taking vitamin D preparations
7. Unable to give written informed consent
8. Unable to swallow tablets orally
9. Atrial fibrilation (to provide a more homogeneous aetiology)
Date of first enrolment28/01/2008
Date of final enrolment31/08/2008

Locations

Countries of recruitment

  • Scotland
  • United Kingdom

Study participating centre

Department of Medicine & Therapeutics
Dundee
DD1 9SY
United Kingdom

Sponsor information

University of Dundee (UK)
University/education

Research and Innovation Services
Dundee
DD1 4HN
Scotland
United Kingdom

Phone +44 (0)1382 384664
Email j.z.houston@dundee.ac.uk
ROR logo "ROR" https://ror.org/03h2bxq36

Funders

Funder type

Charity

Chest Heart and Stroke Scotland (UK)

No information available

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to shareYes
IPD sharing plan summaryAvailable on request
Publication and dissemination plan
IPD sharing planThe protocol is available from the authors on request but is not available online. Study data are available for non-commercial, bona-fide academic analyses in collaboration with the authors; decisions on data access will be made between the investigators and the Sponsor (University of Dundee). Participant consent for unrestricted sharing of individual participant data was not obtained
Contact for data sharing: Dr Catrina Forde (c.forde@dundee.ac.uk)

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Results article results 01/10/2012 Yes No
Basic results 21/02/2018 26/02/2018 No No

Additional files

ISRCTN28737567_BasicResults_21Feb18.pdf
Uploaded 26/02/2018

Editorial Notes

26/02/2018: The following changes were made:
1. Overall trial start date was changed from 01/06/2007 to 30/09/2006
2. Recruitment start date was changed from 01/06/2007 to 28/01/2008
3. Recruitment end date was changed from 30/11/2008 to 31/08/2008
4. Overall trial end date was changed from 30/11/2008 to 31/05/2009
5. Participant inclusion age and gender, participant level data, scientific title and basic results summary were added.
6. Primary and secondary outcome measures were updated.