Lactate Increase in Peripheral Artery Disease

Study Overview
=================
Brief Summary
-----------------
To our knowledge, the measurement of the transcutaneous oxygen pressure during walking is the only continuous method that estimates the importance of ischemia, bilaterally and segment of limb by segment of limb. The determination of the lactates concentration, with micro method from earlobe sampling, is very widely validated in physiology and exercise physiopathology; and it is widely used, by laboratories, for exercise investigation in athletes. We use it in routine to evaluate the presence of functional limitation during tcpO2 tests on a treadmill. The present study hypothesises a significant relationship between lactatemia variation (difference between lactatemia after 3 minutes of recovery from walking and the value at rest) and tcpO2 decrease from rest of oxygen pressure (DROP) values for patients with peripheral artery disease (PAD).

Detailed Description
-----------------
Lactates sample (100 microliter) will be collected at rest Ankle brachial index is measured at rest transcutaneous oxygen pressure is measured at the chest, calves and buttocks and results will be expressed as the minimal value of the DROP index (Limb changes minus chest changes) Patients walk on treadmill (2MPH 10% slope) until exertional limb pain. Lactates sample (100 microliter) will be collected at minute 3 of recovery from walking Correlation of lactate increase to the sum of DROP values wil be studied

Official Title
-----------------
Study of Transcutaneous Exercise Oxymetry, reLationship to LActates Increase in Claudication

Conditions
-----------------
Peripheral Artery Disease, Claudication, Intermittent

Intervention / Treatment
-----------------
* Diagnostic Test: Exercise oximetry


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Age > 18 years old Patient able to walk on a treadmill Patient covered by the French health insurance Patient able to understand the protocol Patient agrees to be involve in the protocol and sign the consent form Exclusion Criteria: Patient refuses to participate at the this protocol Patient has a wash-out period for another clinical trial

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients undergoing exercise oximetry<br>Patients with PAD referred for treadmill testing and exercise oximetry | Diagnostic Test: Exercise oximetry<br>* Sample at rest before the walking test Sample at rest 3 minutes after the end of the walking period<br>* Other names: Capillary blood sampling from the earlobe;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation of lactate results to oximetry | Evaluate the coefficient of correlation between the lactatemia increase from rest and the sum of the observed DROP values of all studied subjects. | one and a half hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation of lactate results to resting Ankle to brachial index (ABI) | Evaluate the coefficient of correlation between the lactatemia increase from rest and the sum of the resting ABI value of all studied subjects.. | one and a half hour |