DrugLib.com — Drug Information Portal

Rx drug information, pharmaceutical research, clinical trials, news, and more



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 Level

Vitamin 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

Page last updated: August 23, 2015

-- advertisement -- The American Red Cross
 
Home | About Us | Contact Us | Site usage policy | Privacy policy

All Rights reserved - Copyright DrugLib.com, 2006-2017