The Acute Effects of Passive Vibration on Cardiovascular Function in Individuals With Stroke

Stroke Clinical Trial

Official title:

The Acute Effects of Passive Vibration on Cardiovascular Function in Individuals With Stroke

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01841840
• Other study ID #: 2012.7712
• Status: Completed
• Phase: N/A
• First received: April 23, 2013
• Last updated: April 24, 2013
• Start date: January 2012
• Est. completion date: July 2012

Study information

• Verified date: April 2013
• Source: Florida State University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial Summary

Stroke is the third leading cause of death in the United States. Of those who are affected by stroke, a third becomes permanently disabled. Risk factors for stroke include, but are not limited to, advancing age, physical inactivity, arterial stiffness, and most commonly, high blood pressure. Stroke is a major form of a much boarder problem, cardiovascular disease (CVD). CVD is considered the primary cause of death in the US. Interestingly, increased arterial stiffness of elastic arteries (carotid and aorta) has been shown to be strongly correlated to CVD and stroke. Increased arterial stiffness is considered an independent risk for the development of CVD and stroke. Hence, arterial stiffness has been suggested as a potential therapeutic target for CVD and more specifically stroke.

Recently, whole-body vibration (WBV) exercise has been proposed as a new and effective method to improve muscle mass and muscle strength in younger and older individuals. It is known that systemic arterial stiffness decreased 40 min after a single WBV session in healthy men. In our laboratory, we have shown that leg arterial stiffness decreases after a session of WBV. Taken together, this data seems to suggest WBV may be used as a viable way to decrease arterial stiffness. Special populations, such as post-stroke patients, may be unwilling or unable to perform WBV exercise so an inactive form of exercise (vibration) therapy is needed.

Passive vibration (PV), allows patients to lie in an inactive, supine position, with their legs placed onto the vibration plate. This exposes the lower limbs to continuous vibration without performing voluntary muscle contraction. PV has been shown to increase skin blood flow on the vibrated extremity through vasodilation in healthy individuals and type 2 diabetics. Previous work in our laboratory has demonstrated that a 10-min session of PV on the legs decreases augmentation index (AIx) , a marker of pressure wave reflection, as well as leg and systemic PWV through decreases in local peripheral resistance in young men. However, the effects of PV on arterial function in post-stroke patients are unknown.

It is hypothesized that post-stroke patients will demonstrate a decrease in leg PWV and central AIx. However, greater responses are expected with the lower vibration frequency.

Description:

The purpose of this study is to examine the effects of one acute bout of low and high frequency passive vibration on blood pressure, heart rate, arterial stiffness, wave reflection, and autonomic function in post-stroke patients.

The specific aim of this study is:

-To evaluate the effects of an acute bout of both high (40Hz/low amplitude) and low frequency (25Hz/high amplitude) passive vibration on arterial function and aortic hemodynamics by assessing blood pressures (systolic, diastolic, mean, pulse pressure), arterial stiffness (aortic, systemic, leg), aortic wave reflection (augmentation index), and autonomic function (heart rate variability).

Recruitment information / eligibility

• Status: Completed
• Enrollment: 11
• Est. completion date: July 2012
• Est. primary completion date: July 2012
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 40 Years to 80 Years

Eligibility

Inclusion Criteria:

• 40-80 years of age

• Resting Blood Pressure between 120/80 and 159/99

• Non-Smoker

• Sedentary or low activity (<120 min per week)

• 25-39.9 kg/m2 BMI

• Diagnosed with stroke for at least 4 months

Exclusion Criteria:

• Younger than 40 and older than 80 years of age

• Resting Blood Pressure below 120/80 or above 159/99

• Smoker

• Physically active

• BMI below 25 kg/m2 or above 39.9 kg/m2

• Diagnosed with stroke for less than 4 months

• Diagnosed with any other cardiovascular diseases besides stroke and stage-1 hypertension

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Crossover Assignment, Masking: Single Blind (Subject), Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Hemiparesis
• Hypertension
• Pre-Hypertension
• Prehypertension
• Stroke

Intervention

Other:
• Low-Frequency Passive Vibration
10 minute session of passive vibration set to a frequency of 25Hz and a high amplitude exposed to the legs
• High-Frequency Pasive Vibration
10 minute session of passive vibration set to a frequency of 40Hz and a low amplitude exposed to the legs

Locations

Country	Name	City	State
United States	Florida State University	Tallahassee	Florida

Sponsors (1)

Lead Sponsor	Collaborator
Florida State University

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Blood Pressures	Non-invasive measures of brachial blood pressure	30 minutes	No
Primary	Arterial Stiffness	Using pulse wave velocity of the aorta, systemic, and legs	30 minutes	No
Primary	Pressure Wave Reflection	Using the augmentation index from radial tonometry	30 minutes	No
Secondary	Body Composition	By measuring fat mass and lean soft tissue mass from dual-energy x-ray absorptiometry and waist circumference	30 minutes	No
Secondary	Autonomic Function	Heart rate variability will be assessed from electrocardiogram	30 minutes	No