Restless Leg Syndrome and Chronic Kidney Disease

Restless leg syndrome (RLS) can disturb your sleep. If you have chronic kidney disease (CKD), it can also disrupt your dialysis time. The uncomfortable and sometimes intense feelings in your legs can make sitting still for your dialysis treatment unpleasant. You may want to cut your session short because the feelings in your legs are unbearable. Sometimes patients are unaware that the sensation in their legs is a medical condition and can be treated.

What is RLS?

RLS is a condition where you feel an uncomfortable sensation in your legs and are compelled to move them. It occurs when you are trying to relax or fall asleep. You may get RLS when you have been sitting or lying down for an extended period of time, such as when you’re on dialysis or sitting in a car or plane. The uncomfortable sensations vary from person to person. Some people report an itchy feeling, while others report a crawling or “creepy” sensation. RLS can also be painful; the sensations can feel like burning, aching or prickling.

Moving your legs gets rid of these uncomfortable feelings. You may find yourself walking or pacing, jiggling your legs and feet or tossing and turning in bed to stop the RLS. The symptoms of RLS are more pronounced at night, particularly at bedtime. This urge to move your legs disrupts your sleep patterns. You may have difficulty falling or staying asleep, which can lead to insomnia. During the day, you may feel fatigued and irritated.

What causes RLS?

RLS generally affects older people. However, there are some health conditions that are associated with RLS. They include the following:

• Nerve damage from diabetes
• CKD
• Perhaps iron deficiency or lack of erythropoietin

Diabetes can contribute to RLS. Diabetes can damage tiny blood vessels and nerves. Often, people with diabetes are told to carefully examine their feet for any outward signs of damage because they may not be able to feel a wound or injury due to nerve damage.

In the past it was thought that iron deficiency or lack of erythropoietin (epo) could be a cause of RLS. A common complication of CKD is low iron levels or anemia. Healthy kidneys produce erythropoietin, a hormone that helps make red blood cells. When the kidneys are damaged, they make little or no erythropoietin. With low iron levels and fewer red blood cells being produced, anemia can develop in the early stages of kidney disease and get worse as the renal disease progresses. Nearly all patients in end stage renal disease (the point where dialysis becomes necessary) have anemia.

Depending on the cause of your anemia (low epo levels, low iron levels or a combination of both), your doctor will prescribe medication or supplements. In addition to treating anemia, it has been shown in animal studies that epo stabilizes and/or prevents nerve damage for those with diabetes. Although the direct cause of RLS isn’t certain, it is believed that treatment with epo and iron supplements still help treat RLS.

More recently studies have shown that RLS may be associated with low levels of parathyroid hormone (PTH). Because people with kidney disease are at risk for bone disease, their doctors will monitor their PTH level to make sure it isn’t too high. In patients suffering from RLS a common trait was that they had low PTH levels. Another common factor in those who reported having RLS was the number of neurologic and psychiatric drugs that were administered. Although it’s difficult to know if either these drugs or low PTH cause RLS, these findings are reasons for doctors to avoid over suppression of PTH and to carefully consider the prescribing of neuropsychiatric medicines.

How is RLS treated?

Restless leg syndrome can be treated by your doctor with epo; iron supplements; altering PTH treatment; changing certain anti-depressants, cold and cough medications or anti-seizure drugs that may be causing or enhancing RLS or may prescribe drugs such as clonazepam or benzodiazepines to alleviate symptoms.

Your doctor may also suggest self-administered home therapies to help you get a better night’s sleep. These might include:

• Massage
• Warm baths
• Warm/cool compresses
• Relaxation techniques
• Changes to your sleep environment
• Exercise