Vitamin K Status and Markers of Vascular Function in Patients With and Without Postural Hypotension

Orthostatic Hypotension Clinical Trial

— VITKOH  

Official title:

Vitamin K Status and Markers of Vascular Function in Patients With and Without Postural Hypotension

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02505282
• Other study ID #: 2011CV14
• Status: Completed
• Phase: N/A
• First received: July 20, 2015
• Last updated: July 23, 2015
• Start date: April 2012
• Est. completion date: August 2014

Study information

• Verified date: July 2015
• Source: University of Dundee
• Contact: n/a
• Is FDA regulated: No
• Health authority: United Kingdom: Research Ethics Committee
• Study type: Observational

Clinical Trial Summary

Postural hypotension is common in older people, leading to falls, decline in function, and dependence. Available treatments have limited efficacy and tolerability; novel approaches to treatment are therefore needed. Decreased vascular health, stiffening of the arteries and consequent decreased vascular reactivity are thought to contribute to postural hypotension and are therefore therapeutic targets.

Recent trial evidence has suggested that vitamin K may exert beneficial effects on vascular health particularly in respect to inhibiting calcification. Calcification increases vascular stiffness, decreases compliance and thus decreases the ability of blood vessels to autoregulate blood pressure and flow - which could contribute to postural drops in blood pressure. Worsened vascular health could also impact adversely on baroceptor function, which is needed for blood pressure autoregulation and which is disrupted in patients with orthostatic hypotension.

Vitamin K intake is below recommended daily intake in 60% of adults in the UK. In animals, vitamin K supplementation may be able to reverse calcification of arteries, and in humans Vitamin K has been shown to arrest decline in carotid artery elasticity compared to placebo. High levels of circulating vitamin K were also associated with lower levels of CRP in the Framingham cohort, suggesting a possible role in the suppression of chronic inflammation that is known to accompany vascular disease. The recent ECKO study suggested that vitamin K may reduce falls and fractures; an intriguing question that follows on from this is whether this could be due to beneficial effects on vascular health and postural hypotension, leading to less dizziness and reduced falls.

This cross-sectional comparative study aims to find whether there is a difference in the vitamin K status of patients with postural hypotension compared to those without postural hypotension and whether differences in vitamin K status are associated with other markers of vascular function in patients with and without postural hypotension. This could potentially lead to new treatments for the condition for which there is currently little of proven benefit.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 49
• Est. completion date: August 2014
• Est. primary completion date: January 2014
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 65 Years and older

Eligibility

Inclusion Criteria:

• 65 years or older

• For postural hypotension group: >20mmHg systolic BP drop or >10mmHg diastolic BP drop on standing, and syncopal symptoms on standing.

• For control group: no fall in BP or <20mmHg systolic BP drop and <10mmHg diastolic BP drop on standing, and no syncopal symptoms on standing. No previous diagnosis of orthostatic hypotension.

Exclusion Criteria:

• On warfarin

• Unable to consent

• Unable to stand unaided

Study Design

Observational Model: Case Control, Time Perspective: Cross-Sectional

Related Conditions & MeSH terms

• Hypotension
• Hypotension, Orthostatic
• Orthostatic Hypotension

Intervention

Other:
• Vitamin K status
Vitamin K status indicated by desphospho-uncarboxylated matrix Gla protein level

Locations

Country	Name	City	State
United Kingdom	Univeristy of Dundee	Dundee	Angus

Sponsors (2)

Lead Sponsor	Collaborator
University of Dundee	British Geriatrics Society

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Serum non-phosphorylated, non-carboxylated Matrix Gla Protein		Day 1	No
Secondary	Vitamin K1 Level		Day 1	No
Secondary	Vitamin D		Day 1	No
Secondary	Flow mediated dilatation	Measure of endothelial function	Day 1	No
Secondary	Pulse wave velocity	Measure of arterial stiffness and reflectivity	Day 1	No
Secondary	Carotid intima media thickness		Day 1	No
Secondary	Pulse wave augmentation index	Measure of arterial stiffness and refelctivity	Day 1	No