Does vitamin D reduce blood pressure and left ventricular (LV) mass in resistant hypertensive patients with vitamin D insufficiency?
| ISRCTN | ISRCTN63688695 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN63688695 |
| EudraCT/CTIS number | 2008-002681-63 |
| Secondary identifying numbers | Res08/A115 |
- Submission date
- 28/03/2008
- Registration date
- 21/04/2008
- Last edited
- 07/11/2017
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Circulatory System
Plain English summary of protocol
Background and study aims
People who have high blood pressure despite taking three or more blood pressure lowering medications have a condition called resistant hypertension. This group of patients struggle to find medications that reduce their blood pressure effectively, and thus remain at higher risk of future heart attack and stroke. Persistently high blood pressure also leads to thickening of the heart muscle, which can lead to impaired heart function and rhythm disturbances. Vitamin D levels are low in many people in Scotland, and low vitamin D levels have been found to be associated with higher blood pressure. The aim of this study is to test whether vitamin D supplements could improve blood pressure and reverse the thickening of the heart muscle that is common in people with resistant hypertension.
Who can participate?
Men and women aged over 18 with resistant hypertension
What does the study involve?
Participants are randomly allocated to receive either a large dose of vitamin D every 2 months, or a dummy (placebo) dose. At the beginning of the study, blood pressure is measured at rest and over 24 hours. Heart muscle thickness is measured using MRI scans in those patients with a thickened heart muscle. The MRI scans are repeated after 6 months, and measured blood pressure at 2, 4 and 6 months.
What are the possible benefits and risks of participating?
The benefit of taking part is that a new way of treating difficult-to-treat high blood pressure might be found. The risks are very small as vitamin D is very safe. It can very rarely increase the risk of kidney stones, although whether it really does this or not is controversial.
Where is the study run from?
Ninewells Hospital (UK)
When is the study starting and how long is it expected to run for?
March 2008 to May 2013
Who is funding the study?
Chest Heart and Stroke Scotland (UK)
Who is the main contact?
Prof. Allan Struthers
a.d.struthers@dundee.ac.uk
Contact information
Scientific
Dept of Clinical Pharmacology
Ninewells Hospital
Dundee
DD1 9SY
United Kingdom
| Phone | +44 (0)1382 383013 |
|---|---|
| a.d.struthers@dundee.ac.uk |
Study information
| Study design | Double-blind placebo-controlled parallel-group randomised 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 reduce blood pressure and left ventricular (LV) mass in resistant hypertensive patients with vitamin D insufficiency? A double-blind, placebo-controlled, parallel-group randomised trial |
| Study objectives | That vitamin D supplementation in patients with resistant hypertension and insufficient vitamin D levels will lead to clinically important reductions in blood pressure. |
| Ethics approval(s) | Ethics Board of Fife, Forth Valley and Tayside Research Ethics Service, 06/08/2008, ref: 08/S1402/31 |
| Health condition(s) or problem(s) studied | Hypertension |
| Intervention | 100,000 units of oral vitamin D3 every two months or placebo. Total treatment duration: 4 months Total follow up: 6 months |
| Intervention type | Supplement |
| Primary outcome measure | Office BP, measured at 0, 2, 4 and 6 months |
| Secondary outcome measures | LV mass index, measured by cardiac magnetic resonance imaging [MRI] at 0 and 6 months |
| Overall study start date | 01/03/2008 |
| Completion date | 01/05/2013 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Sex | Both |
| Target number of participants | 74 |
| Key inclusion criteria | 1. Aged greater than 18 years, either sex 2. Serum 25-hydroxy vitamin D less than 75 nmol/L 3. Office blood pressure (BP) greater than 140/90 mmHg despite three or more anti-hypertensives |
| Key exclusion criteria | 1. Hypertension known to be due to a correctable underlying medical or surgical cause 2. Estimated glomerular filtration rate less than 40 ml/min (by four variable Modification of Diet in Renal Disease [MDRD] equations) 3. Liver function tests (alanine aminotransferase [ALT], bilirubin, alkaline phosphatase) greater than 3 x normal 4. Corrected calcium greater than 2.60 mmol/L or less than 2.15 mmol/L 5. Known metastatic malignancy or sarcoidosis 6. Clinical diagnosis of osteomalacia 7. History of renal calculi 8. Diagnosis of heart failure with left ventricular systolic dysfunction 9. Atrial fibrillation 10. Already taking vitamin D supplements. Consumption of fish oils will not be a contra-indication to enrolment 11. Unable to give written informed consent 12. Pregnant or of childbearing age and not taking reliable contraception |
| Date of first enrolment | 01/01/2009 |
| Date of final enrolment | 01/08/2011 |
Locations
Countries of recruitment
- Scotland
- United Kingdom
Study participating centre
DD1 9SY
United Kingdom
Sponsor information
University/education
Research and Innovation Services
11 Perth Road
Dundee
DD1 4HN
Scotland
United Kingdom
| Phone | +44 (0)1382 383359 |
|---|---|
| j.z.houston@dundee.ac.uk | |
| Website | http://www.dundee.ac.uk/ |
"ROR" |
https://ror.org/03h2bxq36 |
Funders
Funder type
Charity
Private sector organisation / Associations and societies (private and public)
- Alternative name(s)
- Chest Heart & Stroke Scotland, CHSS
- 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 | The protocol is available from the authors on request but is not available online. |
| IPD sharing plan | The datasets generated during and/or analysed during the current study are/will be available upon request from Dr Catrina Forde (c.forde@dundee.ac.uk). 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. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Results article | results | 01/04/2014 | Yes | No | |
| Basic results | 06/11/2017 | 07/11/2017 | No | No |
Additional files
- ISRCTN63688695_BasicResults_06Nov17.pdf
- Uploaded 07/11/2017
Editorial Notes
07/11/2017: Ethics approval details added. The basic results of this trial have been uploaded as an additional file.
06/11/2017: The following changes were made to the trial record:
1. The overall trial start date was changed from 01/10/2008 to 01/03/2008.
2. The overall trial end date was changed from 31/10/2010 to 01/05/2013.
3. Recruitment start and end date added.
4. IPD sharing statement added.
16/11/2016: Publication reference added.
16/02/2009: This record was updated to include amended trial dates; the initial trial dates at the time of registration were:
Initial overall trial start date: 01/08/2008
Initial overall trial end date: 31/07/2010
