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

NCT ID: NCT02505282

Last Updated: 2015-07-24

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 49 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2012-04-30
• Study Completion Date: 2014-08-31

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.

Conditions

Orthostatic Hypotension

Study Design

• Observational Model Type: CASE_CONTROL
• Study Time Perspective: CROSS_SECTIONAL

Study Groups

Orthostatic Hypotension

\>20mmHg systolic BP drop or \>10mmHg diastolic BP drop on standing, and syncopal symptoms on standing

Vitamin K status

Intervention Type: OTHER

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

Control

No fall in BP or \<20mmHg systolic BP drop and \<10mmHg diastolic BP drop on standing, and no syncopal symptoms on standing

Vitamin K status

Intervention Type: OTHER

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

Interventions

Vitamin K status

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

Intervention Type: OTHER

Eligibility 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

• Minimum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

British Geriatrics Society

OTHER

Sponsor Role: collaborator

University of Dundee

OTHER

Sponsor Role: lead

Responsible Party

Matthew Lambert

Clinical Lecturer

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Univeristy of Dundee

Dundee, Angus, United Kingdom

Countries

United Kingdom

Other Identifiers

2011CV14

Identifier Type: -

Identifier Source: org_study_id