PAD: The most important facts about “Intermittent Claudication”

1. What is PAD?
2. What are the consequences of PAD?
3. What increases the risk of PAD?
4. How can PAD be prevented?
5. How are PAD, diabetes and obesity related?
6. What are the symptoms of PAD?
7. How is PAD diagnosed?
8. How is PAD treated?

A walk through the city: stop every few meters, stand still for a moment, walk on, stop again. What looks like leisurely window shopping actually has a different cause: peripheral arterial disease, or PAD for short. In PAD, the circulation in the legs and feet is disturbed or even interrupted by constrictions of and damage to the blood vessels.

In PAD, the muscles are no longer reliably supplied with blood. As a result, those affected sometimes experience so much pain when walking that they have to stop at regular intervals – as if they were strolling from one shop window to the next. For this reason, PAD is also known as intermittent claudication.

In most cases, arteriosclerosis is the underlying disease of the chronic circulatory disorder. Fat deposits (plaques) form on the walls of the blood vessels (arteries) and constrict them. If the plaques burst, a blood clot (thrombus) may form. This affects not only the vessels in the legs, but also the vessels in the heart or brain. In the worst case, this can lead to a heart attack or stroke.

PAD is relatively common: Between 3 and 10 people in 100 are affected in industrialized nations. The number of people with PAD increases steadily with age. Between 15 and 20 in 100 people over the age of 70 suffer from intermittent claudication. PAD is more common in men than in women in younger age groups. At an age of 75 and older, however, women are more likely to have PAD than men.

The stages of PAD

The severity of PAD varies from person to person and can worsen over the course of the disease. PAD can be divided into different stages, depending on how severe the symptoms are.

The names for PAD also change with the stages: While experts refer to early stages as “intermittent claudication”, late stages are referred to as “limb ischemia”, in which a blood vessel becomes partially or completely blocked. In end-stage PAD, parts or even larger areas of the tissue on the legs and/or feet have died off due to the lack of blood flow. In medicine, this is known as necrosis.

The individual stages of PAD are:

• PAD stage I: Asymptomatic, no complaints
• PAD stage IIa: Affected persons can walk a distance of more than 200 meters without pain during the walking test – mild claudication
• PAD stage IIb: Affected persons can walk a distance of less than 200 meters during the walking test without pain – moderate or severe claudication
• PAD stage III: Pain due to reduced blood flow at rest
• PAD stage IV: Ulcers, dead tissue areas (necrosis)

In peripheral arterial disease (PAD), blood flow to the legs is restricted because blood vessels (arteries) that supply the legs with oxygen and nutrients are constricted or – in extreme cases – even blocked. As a result, the tissue is no longer sufficiently supplied.

The poorer the blood supply, the greater the likelihood of ulcers forming or even tissue dying off. In the worst case, there is a risk of amputation of the affected body part.

The prognosis of PAD depends on the stage of the disease. The more advanced the intermittent claudication is, the higher the risk of serious consequences such as amputation. PAD also limits life expectancy – this is particularly true if the disease is already causing symptoms.

Peripheral arterial disease (PAD) is a form of vascular calcification. A healthy lifestyle can help to protect the blood vessels and thus prevent intermittent claudication:

• Give up smoking: Smoking is the most significant risk factor for PAD, as the substances contained in cigarettes and the like damage the blood vessels and thus promote circulatory disorders.
• Exercise regularly: An active lifestyle is important to prevent vascular disease. Just 30 minutes of fast walking or cycling 3 days a week strengthens the cardiovascular system.
• Avoid elevated LDL cholesterol levels: Excessively high LDL cholesterol levels favor PAD. You should therefore have your blood lipid levels checked regularly by a doctor and treated if necessary. In addition to medication, a high-fiber diet with a high intake of vegetables, fruit and whole grain products and a low amount of animal products can also have a positive effect on blood lipid levels.
• Avoid high blood pressure: High blood pressure puts a strain on the blood vessels. Have your blood pressure measured regularly and treat elevated values.
• Treat diabetes: People with diabetes are more likely to suffer from vascular disease, as the increased blood sugar levels damage the blood vessels in the long term. You should therefore try to keep your blood sugar levels within your individual target range.
• Achieve normal weight: Overweight favors PAD. Therefore, aim for a normal weight or try to reduce existing excess weight as much as possible.

People with peripheral arterial disease (PAD) experience pain after a very short time when walking, so that they have to stop. The pain mainly manifests itself in the calves, but also in the thighs or buttocks.

There are other PAD symptoms that may indicate intermittent claudication. These include:

• Dry skin on the legs and feet
• Loss of leg hair
• Poorly healing wounds
• Dry, cool and pale skin
• Severely calloused soles of the feet
• Unusually slow-growing toenails

In men, erectile dysfunction can also occur as a result of vascular calcification.

In order to diagnose peripheral arterial disease (PAD), the attending specialist first asks the patient about his or her symptoms. The doctor then examines the skin and muscles of the affected area and measures the pulse. A stethoscope is used to listen to the blood flow in the arteries in order to detect any abnormalities.

To determine what is called the ankle-brachial index (ABI), blood pressure is first measured in the arms and then in the lower legs. These two values are set in relation to each other. This allows conclusions to be drawn about the extent of the circulatory disorder.

Imaging procedures such as duplex ultrasonography or angiography provide additional information on the condition of the blood vessels.

As people with PAD can walk only short distances without pain, the doctor determines the extent of the symptoms using a walking test. While affected people walk on a treadmill, it is determined how long they can walk without pain or whether they can walk at all.

The treatment of peripheral arterial disease (PAD) depends on the stage of the disease and the severity of the symptoms. There are various possible treatment options:

Counteract existing risk factors

The main cause of intermittent claudication is arteriosclerosis. Adjusting lifestyle and treating or avoiding possible risk factors can delay or prevent the progression of arteriosclerosis. The following measures are recommended:

• No smoking
• Regular exercise
• Balanced diet
• Reducing existing overweight, especially in the case of severe overweight (obesity)
• Treating elevated blood lipid / cholesterol levels
• Regular blood pressure checks
• Treatment of an existing diabetes

Treatment with medication

If necessary, doctors will prescribe drugs. These include active substances that reduce blood clotting (blood thinners) or dilate the blood vessels and thus facilitate blood circulation.

The main symptom of PAD is that the persons affected can no longer walk long distances or quickly feel pain when walking. However, exercise is important for vascular health and general performance. People with PAD are therefore recommended to do targeted walking training to improve their fitness and quality of life. Affected people should exercise for at least 60 minutes a day, walking for 5 to 15 minutes at a time until they feel pain.

Treatment of vascular occlusions

In advanced PAD stages, blood circulation in the legs is significantly restricted. More open wounds and ulcers may develop, which require medical treatment. In addition, painkillers and medication against infections may be used.

In people with advanced PAD, surgical interventions can improve blood circulation in the legs, especially if the quality of life is already severely restricted. For example, the practitioner can insert a catheter, i.e., a very thin tube, up to the narrowed vascular site and deploy a small balloon there, which dilates the vessel and delivers medication on site. A stent, a fine wire mesh made of metal, then stabilizes the dilated blood vessel and keeps it open.

In some cases, surgeons also apply a bypass: As part of an operation, they remove a healthy blood vessel from another part of the body and use it to create a kind of “detour” that bypasses the constriction of the damaged blood vessel.