Restless Legs Syndrome and Its Connection to Shift Work
For shift workers slumping into bed after a long night shift or extended hours work day, a pain that feels like a burning iron on your leg is not the feeling you were hoping for. Restless Leg Syndrome (RLS), a chronic problem sometimes unnoticed by health care, affects almost 10 percent of the population, yet it is still a misunderstood and often forgotten disorder. A shiftwork lifestyle causes workers to face a much greater risk for Restless Leg Syndrome than the normal population. Restless Leg Syndrome often goes undiagnosed for up to twenty years after it rears its ugly head, causing pain, lack of sleep, and irritation, but people can work their way towards recovery. It is important for shift workers to arm themselves with knowledge of RLS and its symptoms, so that they can avoid unnecessary harm.
Background Information (Definition and Causes)
Restless Legs Syndrome (RLS) is a disorder of the nervous system that affects the movement of legs. People who have RLS experience uncomfortable sensations in their legs described as creeping, tugging, tingling, itching or pulling. It is estimated that between 8 and 10% of the population has RLS. About 80% of people with RLS also have Periodic Limb Movement Syndrome (PLMS) which cause legs to jerk every 20 or 30 seconds on and off during the night. Because a significant number of people with RLS/PLMS have difficulty falling or staying asleep, these disorders are also sleep disorders. Symptoms get better when the person moves their legs and they get worse when resting. During long periods of rest it is likely the symptoms will be most severe. And, the symptoms are usually worse when the person is lying down.
RLS can be a primary or secondary disorder. When RLS runs in families, it is primary. Clinical surveys show that about half of all RLS patients report a positive family history. In the case of primary RLS, the disorder often worsens with age. Researchers are currently looking for the gene or genes that cause RLS (see more below). RLS may be related to abnormalities in brain chemicals (neurotransmitters) that regulate muscle movements, or occur as the result of abnormalities in the part of the central nervous system that controls automatic movements. Research is also being done in these areas.
Sometimes RSL appears as the result of another condition or, if already present, worsens as a result of another condition; secondary RLS. One significant secondary cause of RLS is iron deficiency anemia. People with anemia have less than the normal number of red blood cells or less hemoglobin than normal in the blood. Hemoglobin is the chemical compound that generates the red pigment in blood and also carries oxygen from the lungs to the rest of the body. Anemia is usually detected or at least confirmed by a complete blood cell count. People with anemia feel fatigued, tire easily, may appear pale, can develop heart palpitations, and may become short of breath.
Another common secondary cause of RLS is peripheral neuropathy. The term peripheral neuropathy describes a problem with how the nerves outside of the spinal cord are functioning. The symptoms of a neuropathy may
include weakness, numbness, burning pain (especially at night), and a loss of reflexes. Some of the most common causes of neuropathy include repetitive activities such as typing or working on an assembly line. Being overweight or pregnant can cause peripheral neuropathy; as many as 40% of pregnant women complain of RLS symptoms. These symptoms can be very painful; one woman once complained that in the middle of the night she would awake feeling like a hot iron was being placed on her leg.
RLS can also result from a deficiency of vitamin B-12; found primarily in meat, eggs and dairy products. A deficiency of B-12 can also result in anemia. Too much alcohol or caffeine can cause RLS. Certain medications can cause RLS; antidepressant drugs, beta blockers, H2 blockers, antipsychotic drugs and anticonvulsant drugs may cause RLS. In addition, lime disease, kidney disease, damage to the spinal nerves and rheumatoid arthritis are all associated with increased likelihood of RLS. Smoking is associated with increased likelihood of RLS. Stress, fatigue and psychiatric disorders can increase the severity of RLS.
New Studies
To date researchers have suggested the presence of RLS genes on three chromosomes. Current research is ongoing to narrow the gene search to narrower chromosome locations. A report released in July of 2006 evaluated a large Bavarian family that had 16 members with RLS. Nine of them had early on-set RLS. (at age 35 or younger). They also studied five additional family members who had some symptoms but had an uncertain RLS diagnosis. Using genetic samples from the family members the researchers were able to place the RLS gene on chromosome 9p between some specific chromosomal markers. (Liebetanz, Winkelman, Trenkwalder,Putz, Dichgans, Gasser, Muller-Myhsok; Neurology, July 2006; 67(2):320-321)
In September of 2006 a study was released looking at whether exercise can help RLS symptoms. Twenty three people with RLS participated in the study; 11 in the exercise group and 12 in the control group who did no exercise. The exercise group participated in a conditioning program of aerobic exercise and lower body training for three days a week. The aerobic exercise consisted of 30 minutes on a treadmill. The body training included leg extensions, leg press, leg curls and hip and calf exercises. By week 6 the exercise group’s RLS symptoms decreased by about 50%. (Aukerman M., Aukerman D., Bayard, Tudiver, Thorp, Baily; J AM Board Fam Med, Sept-Oct 2006; 19 487-493)
RLS and Shift Work
Shift workers may be at greater risk for secondary RLS. This is due to other health and lifestyle matters that impact shift workers greater than the daytime worker population. According to Study of Shift Workers by Circadian Technologies, Inc. “Health and Extended Hours Operations: Understanding the Challenges, Implementing the Solutions”:
· Only 27.5% of extended hours workers (shift workers) report having good nutritional practices; 78% of shift workers ages 18-24 report not being aware of, or not having, good nutritional habits
· 77% of shift workers report not exercising regularly
· 71% of men, and 53% of women shift workers are overweight
· 34% of shift workers drink 4 or more cups or cans of caffeinated drink on the night shift
· 54% of all shift workers have smoked or currently smoke; 55% of men and 51% of women shift workers smoke, compared to 25% and 21%, respectively, of non-shift workers
· 43% of shift workers drink alcohol on non-workdays
· Shift workers sleep an average 6.5 hours on workdays—nightshift-only workers sleep even less
· 60% of shift workers report feeling drowsy at work several times per month—11.6% report feeling this way several times per shift
As was stated above, repetitive physical activities can cause peripheral neuropathy which can result in RLS symptoms. Many shift work jobs require repetitive physical activity. RLS is associated with being overweight,
smoking, drinking too much caffeine or alcohol, being stressed or fatigued. In addition, a vitamin B-12 deficiency can cause RLS. Many shift workers have poor nutritional practices resulting in vitamin deficiencies.
Diagnosing and Treating RLS
Unfortunately, RLS is often not diagnosed for 10-20 years after symptoms begin. Sometimes RLS symptoms come and go, so they are not always front of mind during an annual physical. Also, many people suffering from poor sleep do not link their sleep problem with their restless legs. There are not any lab tests available to confirm or deny RLS. However, blood tests will confirm if anemia or another vitamin deficiency exists. And, a sleep study will determine if there are other causes of sleep disturbances that can be treated or if RLS is the prevalent cause of sleep disturbance.
Primary care physicians should look at the medicines taken by patience complaining of restless legs to see if any of them might make RLS symptoms worse. As mentioned above, drugs for heart conditions, high blood pressure and depression may worsen RLS effects. Any underlying medical conditions such as anemia, diabetes, kidney disease, Parkinson’s disease or vitamin deficiencies should be treated. In addition, companies needing employees to perform tasks requiring repetitive physical activity should analyze job tasks and activities and make every effort to alternate activities to reduce body stress.
To reduce the impact of RLS, individuals should do the following:
· Focus on eating healthy foods, ensuring balanced nutrition with enough iron and B-12; consider vitamin supplements with medical advice.
· Eliminate or reduce alcohol and caffeine intake.
· Increase activities that may help reduce the impacts of RLS such as aerobic and lower body training as described above, walking and stretching, massage, relaxation techniques, taking warm or cold baths.
· Maintain a regular sleep schedule; adjusting for rotating shifts by always maintaining the same sleep routines
After modifying medications that may be making RLS worse and attempting to improve symptoms with the ideas mentioned above, medication options for treating RLS can be discussed and evaluated by medical care providers. In 2005, Requip (ropinirole) was approved by the U.S. Food and Drug Administration (FDA) for the treatment of moderate to severe RLS. This drug was first approved in 1997 for patients with Parkinson’s disease. In 2006, the FDA also approved pramipexole (Mirapex) for RLS treatment. In addition, several drugs approved for other conditions have undergone clinical studies to treat RLS and have been found to be helpful. These medications fall into four major classes: dopaminergic agents (also used to treat Parkinson’s disease), anticonvulsants, and pain relievers.
More information also is available from the following organization:
Restless Legs Syndrome Foundation
1610 14th Street NW Suite 300
Rochester, MN 55901 USA
rlsfoundation@rls.org
http://www.rls.org
Tel: 507-287-6465
Fax: 507-287-6312
©2007workingnights
This material is provided for personal, non-commercial, educational and informational purposes only and does not constitute a recommendation or endorsement
Tags: chronic problems, drugs, fitness, restless leg syndrome, sleep, smoking, vitamins
