Millions of Americans with restless legs syndrome (RLS) may also have a dangerous risk factor for heart attacks and strokes, a Harvard study suggests. Women with frequent RLS symptoms are up to 41 percent more likely to have high blood pressure—a major threat for developing cardiovascular disease, compared to women who don’t have the neurological disorder. The study was published in the October issue of Hypertension: Journal of the American Heart Association. Previous studies in men have found a similar link between high blood pressure and RLS.
Restless legs syndrome affects up to 10 percent of Americans, with more than five million US adults experiencing moderate to severe symptoms and millions more having a milder form. RLS is estimated to affect nearly one million school-aged kids. It often goes undiagnosed and untreated, either because patients don’t recognize the symptoms or doctors mistake them for other conditions. Here’s a closer look at the study and this common, but often unrecognized disorder.
What is Restless Legs Syndrome?
RLS is a neurological disorder that causes a strong urge to move your legs, due to unpleasant sensations that are typically described as throbbing, creeping, itching, pulling, or gnawing, according to the Restless Legs Foundation. The most distinctive sign of the syndrome is that lying down and trying to relax triggers the symptoms, which are most likely to strike at night. Symptoms can also strike when you are sitting, and can affect the arms, trunk or head, as well as the legs. Typically, moving your legs makes the symptoms better, so people with RLS often keep their legs in motion to reduce or prevent the unpleasant sensations: They may pace the floor, constantly wiggle their legs while sitting, and toss and turn in bed.
How Does RLS Affect Sleep?
One of the major complaints of people with this syndrome is that they have trouble sleeping. More than 80 percent of people with restless legs syndrome also have a common condition called periodic limb movements of sleep (PLMS)—involuntary twitching or jerking movements that occur every 15 to 40 seconds during the night, causing partial awakening leading to chronic exhaustion and daytime drowsiness. Although many RLS sufferers develop PLMS, most people with PLMS do not have RLS.
What Causes RLS?
Certain gene variants have been linked to some cases and low levels of iron in the brain may also be a factor. The National Institute of Health reports there is considerable scientific evidence that restless legs syndrome is related to a dysfunction in brain circuits that use the neurotransmitter dopamine, which is required for smooth, purposeful muscle activity. RLS is also linked to certain medical conditions, such as kidney failure, diabetes and peripheral neuropathy (numbness and tingling in the hands and feet), but it not yet known if these conditions trigger RLS.
Who is at Risk?
Although the symptoms can strike at any age, RLS is more common in people who are middle-aged or elderly, and affects twice as many women as men. It can temporarily affect pregnant women, especially in the third trimester, with symptoms typically disappearing within four weeks of giving birth.
What’s the Link Between RLS and High Blood Pressure?
When the Harvard researchers analyzed data from 65,544 female nurses, ages 41 to 58, they found that women with RLS symptoms were 20 percent more likely to have high blood pressure, while women who had symptoms 15 times or more a month were 41 percent more likely to have high blood pressure, even after other conditions that affect blood pressure, such as obesity and smoking, were taken into account. In an accompanying editorial, Domenic Sica, MD, and David Leszczyszyn, MD, Ph.D. hypothesize that repeated overnight changes in blood pressure due to leg movements during sleep may lead to a rise in daytime blood pressure. However, further research is needed to find out if RLS causes high blood pressure, or if there is another reason why the two conditions strike in tandem.
What’s the Takeaway Message From the Study?
One in three American adults have high blood pressure, which rarely causes symptoms, but boosts risk for a heart attack or stroke. If you have RLS, get your blood pressure checked, and if it’s high, discuss the best treatments to reduce it with your doctor. The American Academy of Family Physicians recommends having your blood pressure measured every two years, or more often, if advised by your doctor. A normal reading is below 120/80.
What’s the Treatment for RLS?
Treatment can involve lifestyle changes, such as cutting down on caffeine and alcohol, quitting smoking, and supplements to treat deficiencies in iron, foliate and magnesium, moderate exercise, massaging the legs, and using a heating pad or ice pack. There are also several medications that may be prescribed, including anti-seizure medications, drugs to improve sleep, and drugs that increase dopamine levels. To read more about RLS and its treatments, visit the website of the Restless Legs Syndrome Foundation.