Vitamin K Status and Markers of Vascular Function in Patients With and Without Postural Hypotension
Information source: University of Dundee
ClinicalTrials.gov processed this data on August 23, 2015 Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Orthostatic Hypotension
Intervention: Vitamin K status (Other)
Phase: N/A
Status: Completed
Sponsored by: University of Dundee
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.
Clinical Details
Official title: Vitamin K Status and Markers of Vascular Function in Patients With and Without Postural Hypotension
Study design: Observational Model: Case Control, Time Perspective: Cross-Sectional
Primary outcome: Serum non-phosphorylated, non-carboxylated Matrix Gla Protein
Secondary outcome: Vitamin K1 LevelVitamin D Flow mediated dilatation Pulse wave velocity Carotid intima media thickness Pulse wave augmentation index
Eligibility
Minimum age: 65 Years.
Maximum age: N/A.
Gender(s): Both.
Criteria:
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
Locations and Contacts
Univeristy of Dundee, Dundee, Angus DD1 9SY, United Kingdom
Additional Information
Starting date: April 2012
Last updated: July 23, 2015
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