George Lundberg, MDDISCLOSURES
I don’t rightly remember when I first learned of restless legs syndrome (RLS). It was many decades ago, and I recognized that once in a while, I would be restless during sleep, tossing and turning, seeking a favorable sleeping position. I felt like I just needed to move my legs around; my gastrocnemii and hamstrings might cramp; and my torso skin might strangely “crawl” a bit, but then normal sleep would return. I never sought medical care for it and used no treatment, except moving my legs when indicated.
My trusty LLM (large language model), Bard, tells me that there are about 53,000 articles about RLS in English, of which, some 20,000 are in the primary source, peer reviewed literature. Count this as one more article. Will it make a difference? Read on and see.
For many centuries (since Sir Thomas Willis in 1672), the symptoms now grouped and categorized as RLS have been recognized and reported but were often dismissed as bizarre and unexplained. The name was applied in 1948 by Dr Karl-Axel Ekborn.
In the 1960s, in sleep labs, RLS became better studied and characterized.
Mayo Clinic describes RLS as “…compelling, unpleasant sensations in the legs or feet…both sides of the body…within the limb rather than on the skin…crawling, creeping, pulling, throbbing, aching, itching, electric…difficult to explain…” Not numbness, but a consistent desire to move the legs.
When I read about it many decades ago, I realized that I may have RLS. But then many months would pass with no recurrence, so I dismissed it as just another of those “symptoms of unknown origin” that my late friend Clifton Meador has written about so eloquently.
I am sure that a lot of people experience this, don’t understand it, and don’t consider it important enough to do anything about. Between 1% and 15% (a wide range) of Americans are believed to be affected by RLS. The cause is unknown, but it seems to run in families. It may be autosomal dominant, but no causative genes have been confirmed.
Treatment of RLS
Many pharmacologic and physical treatments have been tried with some success for some patients, but over time, these treatments have mostly failed.
We know how Big Pharma often operates. A company owns a drug, preferably under patent protection, but without an apparent profitable indication. They need to find a medical condition, ideally one with troublesome symptoms, that the drug might ameliorate to some degree. Armed with a plausible candidate symptom, the company embarks upon a campaign to find people who might want to take the drug. Mass communications, such as direct-to-consumer advertising, can identify large numbers of people who match to pretty much any symptoms, although many of these people never suspected they had a disease, much less a treatable one.
I figured long ago that RLS was just another of those nonspecific entities experienced by many people, making them good candidates for disease mongering.
In 2005, the marketing of GlaxoSmithKline’s (GSK’s) dopamine agonist drug Requip (ropinirole) was approved by the FDA. GSK had already undertaken an intensive promotional campaign for Requip, issuing press releases, advertising to doctors in medical journals, and advertising directly to consumers. To increase general awareness of RLS, GSK’s campaign told consumers that a “new survey reveals that a common yet underrecognized disorder-restless legs syndrome—is keeping Americans awake at night.” GSK was accused of “disease mongering,” trying to turn ordinary people into patients who needed specific drugs.
Within a year, sales of the drug had doubled, climbing from $165 million in 2005 to nearly $330 million in 2006. Soon, 4.4 million prescriptions were written annually for the drug, with sales reported to be nearly $491 million. However, the focus on RLS faded rapidly as the Requip television commercials were pulled from the airwaves following approval of generic ropinirole.
And Requip had competition. Boehringer Ingelheim manufactures pramipexole (brand name Mirapex) another dopamine agonist. Gabapentin enacarbil (marketed as Horizant by UCB Pharma) is also approved for RLS, and Pfizer’s pregabalin (brand name Lyrica) is used off-label to manage symptoms of RLS. Janssen Pharmaceuticals manufactures rotigotine, (brand name Neupro), a dopamine agonist delivered via a transdermal patch.
It is safe to say that RLS is a real clinical entity composed of clearly recognizable symptoms, with no cure and no ending, unless it is associated with iron-deficiency anemia. However, as a disease, it seems to lack etiology, pathology, pathogenesis, pathophysiology, diagnostic findings on physical examination, laboratory tests, or imaging, and any clear strategy for prevention.
Pharmacologic treatments include dopaminergic agents, benzodiazepines, opioids, anticonvulsants, alpha 2–adrenergic agonists and iron salts. Yes, you read that right; RLS is treated with a broad array of different drugs, which is usually a sign that nothing works very well. Some agents work for a while, but none seem to be the definitive solution.
Same for the physical interventions: sleep hygiene, exercise, hot or cold bathing, limb massage, vibratory or electrical stimulation of the feet, stopping caffeine before bedtime. Try everything and see if something works.
Taking the Sugar Challenge
Could the culprit be sugar?
Lacking clarity of scientific understanding of RLS or its treatment from an extensive clinical literature, after ascertaining that RLS is real, one might look for real-world evidence, including well-performed N-of-1 trials.
I am an antisugar guy. Read my prior Medscape columns. I practice what I preach, but sugar does taste good.
Early in November 2023, after a healthy, conservative dinner at home with some wine, I enjoyed a mini Dove bar for dessert. But I didn’t stop there.
Mini Dove bars contain 11 grams sugar. It was also just a few days after Halloween. Having had fewer trick-or-treaters than expected, we had leftovers. Snickers, Milky Ways, Twix mini bars, each with at least 20 grams of sugar.
I ate several of these not long before bedtime. Lo and behold, in the dark of that night, and continuing off and on for a few fitful hours, I had bad RLS. Shifting, tossing, turning, compulsively seeking a new sleeping position only to have to soon move again. Plus, I had repetitive leg cramps and that creepy-crawly skin sensation. An altogether unpleasant experience. Sound sleep eventually arrived, and there were no recurrences over subsequent weeks.
The classic way to determine whether a drug is causing a reaction, condition, or disease is to apply the challenge-dechallenge-rechallenge testing method.
Give the drug, the patient demonstrates the disease finding. Remove the drug, the problem disappears. Rinse and repeat three times. We pathologists first worked this out for drug-induced liver disease, such as steatosis, in the late 1960s. Blinding or double blinding in these N-of-1 situations would be nice but often not practical.
Siwert de Groot, in the Netherlands, published a very convincing use of this technique in 2023: big-time sugar consumption for a week, then low intake of sugar for the following week, repeated three times on one patient.
Very elaborate RLS symptom reporting. I’m pretty convinced from my unintentional challenge and single dechallenge that my unusually high sugar intake resulted in RLS. I will not undergo a rechallenge, although it might be fun to binge on sucrose and see what happens.
If you are serious about identifying or treating RLS, I suggest that you incorporate the International Restless Legs Study Group Severity Rating Scale into your practice, and begin the systematic use of the dechallenge-rechallenge exclusion process for your patients with RLS. Start with sugar and see what happens. Keep records and let the world know what you discover. Be your own clinical investigator. Social media offers you abundant opportunity to share your results, whatever they may be.
How many millions of dollars would Big Pharma lose if patients with RLS just said no to sugar and it worked? Of course, humans being humans, many would probably prefer to continue to gorge on sugar, gain weight, develop diabetes, and then take medications to control their RLS symptoms. But patients ought to at least be given an informed choice.
I will be watching for your reports.
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