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