What is Intermittent Claudication?
Intermittent claudication, or IC, is a condition where you feel pain in the muscles of your lower limbs when you exercise. This happens because your muscles aren’t getting enough oxygen. IC is often a symptom of what’s called peripheral arterial disease (PAD), a condition where your arteries, particularly in your legs, get clogged up due to fatty deposits. IC can typically cause discomfort in the thigh, hip, buttock, and calf muscles. It’s important to note that this pain consistently comes on when you walk and usually eases when you rest. The intensity of the pain can sometimes be an indication of how severely your arteries are blocked.
The main thing to remember about intermittent claudication is that the muscle pain follows a predictable pattern – it routinely occurs during physical activity and lightens up after you rest. The primary cause for this discomfort is poor blood flow to the affected muscles. IC is a common problem, especially in people with diabetes and those who smoke.
What Causes Intermittent Claudication?
Intermittent claudication, a condition that causes discomfort or pain when walking due to poor blood flow, shares many of the same risk factors as atherosclerosis, a disease where plaque builds up inside your arteries. Some risk factors can be changed or managed. This includes smoking, high blood pressure, abnormal cholesterol levels, being overweight, metabolic syndrome (a group of conditions that raise your risk of heart disease, diabetes, and stroke), and diabetes.
However, some risk factors can’t be modified: your age, being male, your family’s health history, and any inherited conditions that make you more susceptible.
In addition to these, researchers are also studying other possible risk factors such as alcohol consumption, exposure to radiation, high levels of C-reactive protein (a substance your liver produces when there’s inflammation in your body), infections, elevated homocysteine levels (an amino acid in your blood), high levels of lipoprotein(a) (a type of fat in your blood), low levels of adiponectin (a hormone that regulates glucose levels and fatty acid breakdown), and high levels of fibrinogen (a protein in your blood that helps it clot).
Besides smoking, having poor kidney function is also considered a significant risk factor for developing intermittent claudication.
Risk Factors and Frequency for Intermittent Claudication
Intermittent claudication, a condition that causes pain during walking, affects a certain portion of the population, particularly those over 60. In this age group, 5% of men and 2.5% of women experience it. Among individuals diagnosed with peripheral arterial disease, 10% to 35% may exhibit signs of “classic” intermittent claudication.
- Victims of intermittent claudication are often over 60.
- 5% of men and 2.5% of women in this age group suffer from this condition.
- Among all peripheral arterial disease patients, 10% to 35% will show “classic” signs of intermittent claudication.
There are some groups that are more likely to develop peripheral arterial disease, including the following:
- People who are over 70.
- Individuals who smoke.
- Patients in the 50-69 age range who have diabetes.
- Those who have other atherosclerotic cardiovascular diseases.
Signs and Symptoms of Intermittent Claudication
Intermittent claudication is a condition where a person experiences leg pain that typically comes on with walking and is relieved with rest. This pain can gradually worsen over time. Depending on where the obstruction in the blood vessels is, the pain might be located in the buttocks or the lower leg. People with aortoiliac disease, which involves the arteries in the belly, often experience pain in the buttocks.
During a physical check-up of those with this condition, the doctor may find signs of decreased blood flow. The affected leg may feel cold and have weaker pulses than usual. The clinician will check for pulses in the groin (femoral pulse), behind the knee (popliteal pulse), top of the foot (dorsalis pedis pulse), and the inner ankle (posterior tibial artery pulse). It’s important to differentiate these symptoms from other sources of leg pain, like spinal stenosis (neurogenic pseudoclaudication), musculoskeletal pain, and swelling and varicose veins associated with venous claudication. Usually, strong foot pulses suggest that intermittent claudication is unlikely.
If pulses are hard to detect by touch, a handheld machine called a Doppler device may be used. In a healthy individual, the blood pressure in the arms and ankles should be about the same or slightly higher in the ankles. There’s a calculation called the ankle-brachial index (measured by comparing the blood pressure in your ankle and arm) that should be done in all people with this condition. If a person’s ankle-brachial index is less than 0.9, it may signal that they have some degree of vascular disease.
Testing for Intermittent Claudication
In order to understand your heart and lung health, your doctor will undertake a detailed heart and lung examination. This examination includes listening to your heart and lungs, and asking you questions about any symptoms you may be experiencing. Based on the level of severity of these symptoms, various other tests can be recommended.
Everyone should get a baseline lipid profile test, which measures the types of fats in your blood. Alongside that, doctor might do a Doppler waveform pulse assessment, which uses sound waves to measure the blood flow through your arteries and veins in your arms, legs, and neck. They might also do an ankle-brachial index test (ABI), which compares your blood pressure in your ankle to your blood pressure in your arm. A normal ABI is between 0.9-1.3. If your ABI is between 0.4 and 0.9, it’s quite common to experience leg pain when walking, a condition known as claudication. An ABI under 0.4 suggests a more serious condition called peripheral arterial disease, in which the arteries in your legs or arms are narrowed. However, if your ABI is over 1.3, it can be an indication of hard, so-called non-compressible arteries often seen in people with diabetes.
For those with such hard arteries, a toe-brachial pressure index (TBI) can be used instead. This is a similar test to the ABI but compares the blood pressure in your toe to your arm. For healthy individuals, a TBI should be between 0.70 and 0.80.
If you’re experiencing symptoms of claudication or peripheral arterial disease but your ABI or TBI is normal, the doctor may suggest an exercise test. In most people, ABI usually increases with exercise. If yours decreases by more than 20% after exercise, it suggests you may have vascular disease, and further diagnostic tests and a specialist’s opinion should be sought.
To accurately assess the severity and progression of vascular disease, doctors utilize three major classification systems: the Wound/Ischemia/Foot Infection (Wifi), Rutherford, and Fontaine scales. These systems take into account symptoms such as intermittent claudication.
To establish where blood vessels might be affected, doctors can use several types of imaging tests such as ultrasound, a CT scan, magnetic resonance angiography, and peripheral angiography. If they discover that disease is located in the large artery supplying your lower body (the aorta) or the arteries that branch off it to supply your pelvis and legs (the iliac arteries), this is typically referred to as ‘inflow’ disease, and you might feel pain in your thigh or buttock muscles. Disease occurring below the fold of the groin, such as in the leg arteries, is commonly associated with claudication affecting the calf muscles.
Treatment Options for Intermittent Claudication
Intermittent claudication is a condition where pain develops in parts of your body, like your legs, after physical activity due to insufficient blood flow. If you’re having this issue, don’t worry too much, as only 1-2% of people with this condition progress to a stage where the disease threatens the limb. So, doctors usually advise against rigorous treatments at first.
For most people with intermittent claudication, non-surgical treatments can help manage the condition. These treatments include quitting smoking, taking certain types of medications (like antiplatelet drugs to prevent blood clots and statins to lower cholesterol levels), adjusting their blood pressure and managing their blood sugar levels, and participating in structured walking programs. These programs can improve the distance you can walk without pain more than drug therapy alone can. It’s important to keep in mind, though, that continuing to smoke while undergoing walking therapy can limit its benefits. Doctors usually recommend a three-month program of smoking cessation, walking, and a medication called cilostazol. Be aware that one common side effect of cilostazol is headaches, which might mean you’ll need to adjust the dose. Patients receiving these treatments should check in with their doctors regularly to assess if their symptoms are improving. Most are advised to take three ten-minute walks daily.
In addition, any patient with intermittent claudication or other diseases affecting the peripheral arteries (blood vessels outside the heart) should be screened for heart disease as well. If symptoms become worse despite non-surgical treatment, or if symptoms significantly affect your lifestyle or ability to function, then surgical treatments might be considered. Decisions about invasive treatments can depend on the specific characteristics of the artery blockages and a patient’s overall health outlook. Initial surgical treatments are typically minimally invasive and can involve procedures such as angioplasty (widening of the artery), stenting (inserting a tube to keep the artery open), or atherectomy (removing plaque from the artery).
These procedures are generally performed through the femoral artery (the artery in your thigh). Blockages that involve multiple sites, are long, or have heavy calcium deposits may not be treatable with these minimally invasive methods. For those cases, more invasive procedures may be needed, which might involve removing the plaque directly (endarterectomy) or bypassing the blocked area (using either a vein from the patient or a synthetic material as a new pathway for blood flow).
There are guidelines from the Society for Vascular Surgery called TASC II that can assist doctors in deciding whether to use minimally invasive or traditional surgery based on the specifics of the blockage. But keep in mind that any surgical procedure carries risks, which might include blood clots forming in the blood vessels or graft, in-stent narrowing or fracture, and infection.
What else can Intermittent Claudication be?
When dealing with intermittent claudication (pain caused by reduced blood flow during exercise), doctors need to consider several conditions that might cause similar symptoms. These include:
- Sciatica
- Atheroembolic disease
- Venous insufficiency
- Vasculitis
What to expect with Intermittent Claudication
The outcome of intermittent claudication, or pain and cramping in the lower leg due to inadequate blood flow, depends on several factors. If you continue to smoke, have uncontrolled high blood pressure, or high blood sugar levels, your condition may get worse. This could eventually lead to a lack of blood supply (ischemia), tissue death (necrosis), and could even result in the amputation of your limb.
Besides smoking, two things that can make the outcome worse are diabetes and old age. In general, people suffering from intermittent claudication tend to live shorter lives compared to those of the same age who don’t have the condition. This is mainly because these individuals often have coronary artery disease, which affects the heart’s blood supply.
About 5 to 30 percent of people with this condition may not survive after 10 years, but this largely depends on how serious their vascular disease, which affects the body’s blood vessels, is.
Possible Complications When Diagnosed with Intermittent Claudication
Intermittent claudication can lead to several complications. Here are the most common ones:
- Difficulty in exercising for extended periods
- Slow healing of wounds
- Impotence or erectile dysfunction
- ‘Blue toe syndrome’ where the toes turn blue due to lack of blood supply
- Leg suffering from inadequate blood supply or ‘ischemic leg’
Preventing Intermittent Claudication
The individual must be informed about the importance of giving up smoking and keeping their weight in check for good health. Regular exercise and consuming nutritious food are also an integral part of maintaining a healthy lifestyle. These are key measures to live a healthy life.
