Global Vascular Effects of Intermittent Pneumatic Compression-Pilot Study

Not Applicable

Completed

Interventions: Device: Intermittent pneumatic compression of the lower extremities

Brief Summary: Intermittent pneumatic compression (IPC) of the lower extremities is a well-established technique for preventing deep vein thrombosis (DVT) and for treating venous stasis. IPC will be done in the home for 3 divided hours every day for 4 weeks. Lab tests, brachial ultrasound and MRI testing will be performed at baseline and after 4 weeks of daily IPC therapy.

See detailed description for increase in healthy control subjects.

Detailed Description: Intermittent pneumatic compression (IPC) of the lower extremities is a well-established technique for preventing deep vein thrombosis (DVT) and for treating venous stasis.

Four categories of discoveries suggest that there may be potential of IPC to have global vascular benefits:

1. IPC of the arms prevents DVT in legs;

2. Nitric oxide released by vascular endothelial cells exerts protective effects on blood vessels;

3. IPC increases nitric oxide availability locally in the lower extremity;

4. Nitric oxide may be transported in blood and released at distant sites, particularly in a hypoxic setting. Therefore, we propose to test the effects of lower extremity IPC on global nitric oxide availability.

We will enroll 4 categories of subjects.

The first 3 categories will have only 1 hour of leg compression. Baseline cholesterol will be drawn for screening labs Brachial ultrasound and NO measurements will be done before and after 1 hr of IPC. No MRI will be done on these groups.

Category 4 will have baseline labs and testing to include:

Brachial ultrasound,NO measurements and MRI will be done before and after 4 weeks of daily IPC therapy.

Category 1, 21-40 yrs healthy male or female

Category 2, 50 yrs plus healthy males or females

Category 3, 50 yrs plus aged matched controls with known heart disease

Category 4, 50 yrs plus12 patients with coronary artery disease.

Recruitment & Eligibility

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Arm && Interventions

Group	Intervention	Description
Intermittent leg compression	Intermittent pneumatic compression of the lower extremities	Intermittent leg compression daily for 3 hrs a day for 4 weeks

Primary Outcome Measures

Name	Time	Method
Plasma S-nitrosothiols	baseline	nM
Brachial Diameter	1 hour after leg IPC	mm
Brachial Flow Dilation	1 hour after IPC	Brachial Flow Mediated dilation, %
Brachial Occlusion-mediated Constriction	1 hour after IPC	Brachial Occlusion-mediated constriction measured via ultrasound, %
Plasma Nitrite	1 hour after IPC	nM
Brachial Flow Velocity	50 minutes into IPC	Measured using ultrasound, units cm/sec.
Red Blood Cell Nitric Oxide	1 hour after IPC	nM