Vitamin K Status and Markers of Vascular Function in Patients With and Without Postural Hypotension
- Conditions
- Orthostatic Hypotension
- Interventions
- Other: Vitamin K status
- Registration Number
- NCT02505282
- Lead Sponsor
- University of Dundee
- Brief 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.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 49
- 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.
- On warfarin
- Unable to consent
- Unable to stand unaided
Study & Design
- Study Type
- OBSERVATIONAL
- Study Design
- Not specified
- Arm && Interventions
Group Intervention Description Orthostatic Hypotension Vitamin K status \>20mmHg systolic BP drop or \>10mmHg diastolic BP drop on standing, and syncopal symptoms on standing Control Vitamin K status No fall in BP or \<20mmHg systolic BP drop and \<10mmHg diastolic BP drop on standing, and no syncopal symptoms on standing
- Primary Outcome Measures
Name Time Method Serum non-phosphorylated, non-carboxylated Matrix Gla Protein Day 1
- Secondary Outcome Measures
Name Time Method Pulse wave velocity Day 1 Measure of arterial stiffness and reflectivity
Carotid intima media thickness Day 1 Flow mediated dilatation Day 1 Measure of endothelial function
Vitamin D Day 1 Pulse wave augmentation index Day 1 Measure of arterial stiffness and refelctivity
Vitamin K1 Level Day 1
Trial Locations
- Locations (1)
Univeristy of Dundee
🇬🇧Dundee, Angus, United Kingdom