You may already know that cardiovascular disease is the leading cause of death among both men and women in America, but fewer people realize that a wide range of coronary conditions fall under this umbrella term. When we talk about heart-related deaths, we may be talking about "the big ones"—heart attack or stroke—but very often, the culprit is a lesser known coronary condition such as peripheral artery disease (PAD).
Right now, at least 6.5 million Americans over the age of 40 are living with this potentially life-threatening condition, and many will go on to die from related coronary causes. That's why experts are urging the public to learn the signs of PAD, including a surprising red flag that comes in the form of progressive weakness in one body part. Read on to find out which symptom means it's time to have your heart checked, and why you should include a PAD screening in your evaluation.
If you feel weakness in your leg muscles, get your heart checked.
If you experience weakness in your legs, it could be due to peripheral artery disease, a condition in which the blood vessels become increasingly narrow or blocked. As blood flow becomes restricted in the lower legs—the area where blood vessels are most likely to be affected by PAD—many patients develop muscle atrophy in their calves. If this happens, you may notice shrinking or wasting in muscle tissue of your lower legs.
According to a 2020 study published in Arteriosclerosis, Thrombosis, and Vascular Biology, a journal of the American Heart Association (AHA), "lower extremity peripheral artery disease is associated with reduced calf muscle area and increased calf muscle fatty infiltration and fibrosis." The researchers add that "even within the same individual, the leg with more severe ischemia [restricted blood flow] has more adverse calf muscle characteristics than the leg with less severe ischemia."
Many PAD patients experience reduced mobility as a result.
Reduced physical activity is the most common cause for muscle atrophy in aging individuals. However, the reverse is also true—muscle atrophy can in turn lead to further reduced mobility. In PAD patients, this can create a dangerous cycle which is hard to reverse.
"Because of reduced lower extremity perfusion and reduced energy and oxygen delivery to leg muscles, people with PAD walk significantly shorter distances in a six-minute walk test and have slower walking velocity and lower physical activity than people without PAD, even after adjusting for potential confounders," explains the AHA study. "Over a six-month period, people with PAD typically decline by 10 miles in the distance they are able to walk in six minutes, and 20 percent to 25 percent report new mobility loss, defined as difficulty walking up and down a flight of stairs or walking quarter mile without assistance," the researchers write.
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PAD patients with this symptom may also develop cellular abnormalities.
Beyond causing reduced mobility, research suggests that those with muscle wasting resulting from PAD often have certain mitochondrial abnormalities within the affected leg tissue. These abnormalities are believed to cause oxidative stress, reduce calcium retention, and enhance cell death, researchers explain. "Therefore, targeting mitochondria might be a promising therapeutic approach in PAD," says a 2019 study published in the Journal of Clinical Medicine.
Some argue that current treatments fail to meet the needs of patients with PAD-related muscle atrophy. "Current treatments for PAD are focused primarily on re-establishing blood flow to the ischemic tissue, implying that blood flow is the decisive factor that determines whether or not the tissue survives. Unfortunately, failure rates of endovascular and revascularization procedures remain unacceptably high," writes a 2020 study published in the journal Antioxidants.
However, many treatment options—which may include medication, lifestyle interventions, or surgery—have been shown to greatly improve patient outcomes. Speak with your doctor to find out if PAD treatment is right for you.
PAD can have other serious consequences.
Besides the impact peripheral artery disease can have on your muscle tone, strength, and physical endurance, it can also have major implications for your broader heart health. That's because PAD is caused by a buildup of fatty plaques in the arteries (commonly known as arteriosclerosis)—the same plaque that can cause heart attack, blood clots, and stroke.
Overall, PAD patients have a high risk of dying from cardiovascular causes. In fact, those with severe limb ischemia—the kind that's known to cause muscle wasting—has been linked with a 75 percent likelihood of mortality within 10 years of a PAD diagnosis, according to a 2018 study published by Elsevier. The researchers behind the Antioxidants study further note that "muscle function is a strong predictor of mortality."
This makes it crucial to get a PAD screening if you notice that your leg muscles are becoming weak or feel like they're wasting away. There are several treatment options available, which can improve your health and quality of life. Talking to your doctor or medical provider is the first step.