Exercise as it relates to Disease/Effects of Exercise for Patients with Peripheral Arterial Disease

This Wiki Fact Sheet is an analysis of the article 'Exercise training improves functional status in patients with peripheral arterial disease' by Regensteiner, J. G., Steiner, J. F., & Hiatt, W. R. (1996)

This analysis has been created by student u3099884 for the University of Canberra: Health, Disease and Exercise unit.

Background
Atherosclerotic Peripheral Arterial Disease (PAD) of the lower extremities, when it is associated with intermittent claudication, results in impaired walking ability. This study was conducted to investigate the effect exercise training rehabilitation programs have on patients with PAD, to help improve health and quality of movement in everyday life activities.

What Is Peripheral Arterial Disease?
Atherosclerotic Peripheral Arterial Disease (PAD) results in blockages, build up of fatty deposits (plaques), to blood flow in arteries in the arms and legs. Lower extremity PAD, often presents with pain when you are about to move, normally walking or running, which is known as 'intermittent claudication'. Intermittent Claudication is defined as pain in the muscles of the leg when walking or moving and the pain then subsides with rest.

Risk Factors For PAD

 * Smoking
 * Diabetes
 * High Blood Pressure
 * High Cholesterol
 * Old Age (Over 70 years)

Cigarette smoking is the most correctable risk factor for development of PAD, whereas age is the most irreversible risk factor.

Symptoms
The most common symptom for people with lower extremity PAD is intermittent claudication. This is often described as a cramp in the leg, fatigue, numbness, heaviness or weakness.

Common Symptoms

 * Thigh or calf pain with exertion (Claudication)
 * Diagnosed with ABI Test - No symptoms
 * Pain in legs and feet at rest
 * Varying blood pressure in legs

Diagnosis
It is estimated that 5% of adults over 50 and 12-20% over 65 have PAD and 20% over 70 have PAD. Doctors recognise that PAD is becoming a much more prevalent problem in the elderly and can diagnose PAD on the basis of medical history with a physical examination which focuses on the heart and blood vessels. Efficiently documenting the presence and severity of PAD in the lower extremities is through measurement ABI (ankle brachial index). The ABI can be calculated by dividing ankle systolic pressure measure with blood pressure at malleolar level by the higher of the two brachial pressures.

Treatment

 * Quitting smoking completely
 * Exercise
 * Medication
 * Surgery

Where Is The Research From?
The study was conducted at the University of Colorado School of Medicine Human Subjects committee, and informed consent was gained from the enrolled students. The article was from the Department of Medicine, Section of Vascular Medicine, and the Center for Health Services Research, University of Colorado Health Sciences Center, Denver. This study was a continuation from previous research of a 12 week treadmill exercise training program, and whether a further 12 weeks would maintain improvements in PAD. Lead researcher, Judith Regensteiner, has expertise in cardiovascular diseases, with PHD in Cardiovascular Pulmonary Research, UC Denver (1986) and subjects for majority of Judith's research comes from patients admitted to the University Hospital in Denver, Colorado.

What Kind of Research Was This?
This research was a controlled randomised three-group trial that was conducted over 24 weeks. There are limited treatment options for patients with PAD, this research was conducted to assess the results and impact different exercise treatments had for increased patient ambulation capacity.

This randomised trial investigated the effects of strength training and treadmill training on functional status of patients with PAD, against a control non-exercising group. Randomised trials aim to allocate the participants of research into random groups with different conditions, and are viewed as the gold standard for clinical research.

Aim
This study had two main aims:
 * Investigate the assumption that a treadmill-training program would improve the functional status of daily activities for patients with PAD
 * Investigate the effects of strength training on improved functional status for patients with PAD

Method
44 males were evaluated for this study, all with disabling intermittent claudication. Claudication symptoms must have been stable over a 3-month period and PAD was confirmed by the ABI test with pressure ratio of less than 0.94 at rest that decreased to less than 0.73 after exercise.

Questionnaires and activity monitors were administered to the patients on entry into the study and after the 12 and 24 weeks. Of the 44 patients 15 were excluded and 29 were enrolled and randomised into the study. Exclusions from the research if:
 * Unable to walk on a treadmill at speed 2 mph
 * Limited exercise capacity by : Angina, Congestive Heart Failure, Arthritis, Chronic Obstructive Pulmonary Disease, Diabetes

29 patients were left and were randomised into 3 groups to 12 weeks of exercise training.
 * Treadmill training – 3 hr/week at work intensity sufficient to produce claudication
 * Strength training – 3 hr/week of resistance training for six muscle groups in the leg
 * Non-exercising control group

Functional status was assessed by questionnaires illustrating walking ability (walking Impairment Questionnaire, WIQ), habitual physical activity level (Physical Activity Recall, PAR), overall health survey and activity levels monitored.

Results
12 weeks of treadmill training resulted in improvements in functional status, indicated from increase in PAR-assessed physical activity, overall fitness functioning and increased activity level numbers. The WIQ-assessed ability to walk distances and claudication severity scores were also improved. After an additional 12 weeks of training all improvements were maintained.

Treadmill Exercise Performance
These patients increased their peak walking time by 74% ± 58% after 12 week, and a further 12 weeks of training resulted in a further increase of 49% ± 53%. All questionnaire results improved and were maintained.

Strength Training
These patients had an increase in peak walking time of 30% ± 48% after 12 weeks, and a further 12 weeks of training resulted in 54% ± 25%. All questionnaire results improved and were maintained.

Control
The patients in this group had no change in peak walking time and no improvements in questionnaire results.

Conclusions
This 24-week study resulted in improvements in peak exercise capacity, walking efficiency, claudication pain severity and physical functioning assessed by three different questionnaires and an activity monitor was also improved. However, this laboratory measure may not reflect changes in functional status during daily activities. The results confirm an increase in treadmill exercise performance, which also reflects improvements in physical function. Consequently, these improvements could potentially enhance the ability to have increased activity in everyday life and should be considered as a treatment option for patients with PAD.

Some limitations from this study include:
 * All subjects were male
 * Was a laboratory measure which may not reflect everyday activities
 * Severity and symptoms of PAD varies from patient to patient

Future studies should addresses the role exercise training has on patients with PAD and other conditions like diabetes or coronary artery disease.

Practical Advice
Before starting any form of physical activity, people suffering with PAD should consult their doctor or local healthcare professional. Pre-exercising screening tools should be used. If people are physically inactive it is recommended to gradually build up exercise intensities. People with PAD suffer different symptoms and it varies in severity, depending on the condition different exercise techniques may work better than others.

Even if you don't show symptoms of Peripheral Arterial Disease, you may need to see your doctor if you are:
 * Over age 70
 * Over age 50 and have a history of diabetes or smoking
 * Under age 50, but have diabetes and other peripheral artery disease risk factors, such as obesity or high blood pressure

Further Information
For further information on Peripheral Arterial Disease follow the links below:
 * Better Health Channel: https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/peripheral-vascular-disease.
 * Health Direct: https://www.healthdirect.gov.au/peripheral-vascular-disease.
 * Australian Institute of Health and Welfare: http://www.aihw.gov.au/cardiovascular-disease/what-is-cvd/.