Vitamin K to improve markers of vascular health and physical function in older people with vascular disease

ISRCTN	ISRCTN93213492
DOI	https://doi.org/10.1186/ISRCTN93213492
Secondary identifying numbers	R11/A137

Submission date: 04/03/2011
Registration date: 28/03/2011
Last edited: 22/08/2017

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
Low intake of vitamin K in the diet has been linked to a higher risk of heart attacks and strokes. This may be because vitamin K is important in keeping blood vessels in good health; low levels of vitamin K are associated with stiffer blood vessels and deposits of calcium in the blood vessel wall. Vitamin K may also be important in keeping nerves working well which are important in maintaining balance and avoiding falls. It is not known whether taking extra vitamin K (as a tablet) can improve balance or blood vessel health, so the aim of this study is to test whether taking a vitamin K tablet for 6 months improves blood vessel health and improves balance in older people who have had (or are at risk of) a heart attack or stroke.

Who can participate?
Older people aged 70 and over who have had (or are at risk of) a heart attack or stroke

What does the study involve?
Participants are randomly allocated to take either vitamin K or a matching placebo (dummy) tablet once a day for 6 months. They are then followed up to assess their blood vessel health and balance.

What are the possible benefits and risks of participating?
If vitamin K improves blood vessel health, it might reduce the risk of heart attacks and strokes, but this study is too small to show this directly. Vitamin K is safe with no known side effects. It can interfere with the action of the drug warfarin, which is why patients on warfarin are excluded from the study.

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

When is the study starting and how long is it expected to run for?
August 2011 to March 2013

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

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

Contact information

Dr Miles Witham
Scientific

Ageing and Health, Ninewells Hospital
Dundee
DD1 9SY
United Kingdom

ORCID ID	0000-0002-1967-0990
Phone	+44 (0)13 8263 2436
Email	m.witham@dundee.ac.uk

Study information

Study design	Parallel-group double-blind placebo-controlled randomised trial
Primary study design	Interventional
Secondary study design	Randomised parallel trial
Study setting(s)	Other
Study type	Treatment
Participant information sheet	Not available in web format, please use the contact details to request a patient information sheet
Scientific title	Vitamin K to improve markers of vascular health and physical function in older people with vascular disease: a randomised controlled trial
Study acronym	KIMVASC
Study objectives	To test whether vitamin K supplementation improves markers of vascular health in older people with vascular disease.
Ethics approval(s)	East of Scotland NHS Research Ethics Committee, 12/09/2011, ref: 11/ES/0009
Health condition(s) or problem(s) studied	Vascular disease
Intervention	Vitamin K2 (MK7 subtype) 100 mcg per day or placebo. Added 18/08/2017: Participants are randomised to take either: 1. Vitamin K2 (MK7 subtype) given as 100 mcg oral tablet once a day for 6 months 2. Matching placebo tablet, given once a day for 6 months Treatment in both arms given for 6 months, which is also the length of follow up.
Intervention type	Supplement
Primary outcome measure	Flow-mediated dilatation of the brachial artery measured at baseline and 6 months
Secondary outcome measures	Measured at baseline, 3 months and 6 months: 1. Markers of vascular function: 1.1. Arterial stiffness and reflectivity, measured using pulse wave velocity and augmentation index 1.2. Carotid intima-media thickness and compliance 2. Markers of vascular prognosis: brain natriuretic peptide (BNP), office blood pressure (BP) (lying and standing), total cholesterol, high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol 3. Markers of inflammation: high-sensitivity C-reactive protein 4. Serum MK7 levels, measured by high-performance liquid chromatography (HPLC) 5. Markers of physical function: 5.1. Short Physical Performance Battery; predicts disability, falls and death 5.2. Balance, measured using force plate analysis 5.3. Grip strength as a test of maximal muscle strength; predicts institutionalisation and death
Overall study start date	01/08/2011
Completion date	31/03/2013

Eligibility

Participant type(s)	Patient
Age group	Senior
Sex	Both
Target number of participants	80
Key inclusion criteria	1. Aged 70 and over 2. At least one of the conditions: 2.1. Hypertension (based on recorded diagnosis from primary or secondary care) 2.2. Diabetes mellitus (based on recorded diagnosis from primary or secondary care) 3. Established vascular disease: myocardial infarction [based on symptoms of ischaemia or electrocardiogram (ECG) changes, plus rise in cardiac enzymes] 4. Percutaneous transluminal coronary angioplasty 5. Coronary artery bypass grafting 6. Stroke/transient ischaemic attack (TIA) (diagnosis established in secondary care) 7. Peripheral vascular disease (symptoms of peripheral ischaemia and either a previous ankle/brachial pressure index < 0.7 or previous evidence of arterial stenosis on angiography or ultrasound)
Key exclusion criteria	1. Atrial fibrillation 2. Taking warfarin 3. Unable to give written informed consent 4. Unable to walk without human assistance (walking aids are permitted)
Date of first enrolment	01/09/2011
Date of final enrolment	30/09/2012

Locations

Countries of recruitment

Scotland
United Kingdom

Study participating centre

Ninewells Hospital

Dundee
DD1 9SY
United Kingdom

Sponsor information

Tayside Academic Sciences Collaboration (UK)
University/education

Level 3 Residences, Geroge Pirie Way, Ninewells Hospital
Dundee
DD1 9SY
Scotland
United Kingdom

Phone	+44 (0)13 8274 0489
Email	TASC@dundee.ac.uk
Website	http://www.tasc-research.org.uk
"ROR"	https://ror.org/049x86d03

Funders

Funder type

Charity

Chest Heart and Stroke Scotland (ref: R11/A137)
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	09/11/2017
Individual participant data (IPD) Intention to share	Yes
IPD sharing plan summary	Available on request
Publication and dissemination plan	Manuscript accepted for publication.
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	01/03/2016		Yes	No
Basic results		04/08/2017	22/08/2017	No	No

Additional files

ISRCTN93213492_BasicResults_04Aug2017.pdf: Uploaded 22/08/2017

Editorial Notes

22/08/2017: The basic results of this trial have been uploaded as an additional file.
18/08/2017: Interventions details and plain English summary added.
09/08/2017: Ethics approval details added.
04/08/2017: Recruitment dates confirmed, IPD sharing statement added.
16/11/2016: Publication reference added.