Physician-diagnosed restless legs syndrome in a large sample of primary medical care patients in western Europe: Prevalence and characteristics

A survey-based approach on restless legs syndrome: practices and perspectives among Italian neurologists

INTRODUCTION

Restless Legs Syndrome (RLS) is a widely prevalent and complex neurological disorder. Despite notable advancements in managing RLS, the disorder continues to face challenges related to its recognition and management.

OBJECTIVE

This study seeks to gain comprehensive insights into the knowledge and clinical practices among Italian neurologists regarding RLS diagnosis, management, and treatment, comparing approaches among general neurologists, movement disorder specialists, and sleep experts.

METHODS

Members of the Italian Society of Neurology, the Italian Society of Parkinson and Movement Disorders, and the Italian Association of Sleep Medicine were invited to participate in a 19-question online survey.

RESULTS

Among the 343 surveyed neurologists, 60% categorized RLS as a "sleep-related movement disorder." Forty% indicated managing 5-15 RLS patients annually, with sleep specialists handling the highest patient volume. Of note, only 34% adhered strictly to all five essential diagnostic criteria. The majority (69%) favored low-dosage dopamine agonists as their first-line treatment, with movement disorder specialists predominantly endorsing this approach, while sleep experts preferred iron supplementation. Regular screening for iron levels was widespread (91%), with supplementation typically guided by serum iron alterations. In cases of ineffective initial treatments, escalating dopamine agonist dosage was the preferred strategy (40%).

CONCLUSIONS

These findings underscore a lack of a clear conceptualization of RLS, with a widespread misconception of the disorder as solely a movement disorder significantly influencing treatment approaches. Disparities in RLS understanding across neurology subspecialties underscore the necessity for improved diagnostic accuracy, targeted educational initiatives, and management guidelines to ensure consistent and effective RLS management.

Targeting the adenosinergic system in restless legs syndrome: A pilot, "proof-of-concept" placebo-controlled TMS-based protocol

Restless Legs Syndrome (RLS) is a common sleep disorder characterized by an urge to move the legs that is responsive to movement (particularly during rest), periodic leg movements during sleep, and hyperarousal. Recent evidence suggests that the involvement of the adenosine system may establish a connection between dopamine and glutamate dysfunction in RLS. Transcranial magnetic stimulation (TMS) is a non-invasive electrophysiological technique widely applied to explore brain electrophysiology and neurochemistry under different experimental conditions. In this pilot study protocol, we aim to investigate the effects of dipyridamole (a well-known enhancer of adenosinergic transmission) and caffeine (an adenosine receptor antagonist) on measures of cortical excitation and inhibition in response to TMS in patients with primary RLS. Initially, we will assess cortical excitability using both single- and paired-pulse TMS in patients with RLS. Then, based on the measures obtained, we will explore the effects of dipyridamole and caffeine, in comparison to placebo, on various TMS parameters related to cortical excitation and inhibition. Finally, we will evaluate the psycho-cognitive performance of RLS patients to screen them for cognitive impairment and/or mood-behavioral dysfunction, thus aiming to correlate psycho-cognitive findings with TMS data. Overall, this study protocol will be the first to shed lights on the neurophysiological mechanisms of RLS involving the modulation of the adenosine system, thus potentially providing a foundation for innovative "pharmaco-TMS"-based treatments. The distinctive TMS profile observed in RLS holds indeed the potential utility for both diagnosis and treatment, as well as for patient monitoring. As such, it can be considered a target for both novel pharmacological (i.e., drug) and non-pharmacological (e.g., neuromodulatory), "TMS-guided", interventions.

Clinical features, polysomnography, and genetics association study of restless legs syndrome in clinic based Chinese patients: A multicenter observational study

STUDY OBJECTIVES

To systemically describe the clinical features, polysomnography (PSG) finding, laboratory tests and single-nucleotide polymorphisms (SNPs) in a clinic based Chinese primary restless legs syndrome (RLS) population.

METHODS

This observational study, conducted from January 2020 to October 2021 across 22 sleep labs in China, recruited 771 patients diagnosed with RLS following the 2014 RLSSG criteria. Clinical data, PSG testing, and laboratory examination and SNPs of patients with RLS were collected. A total of 32 SNPs in 24 loci were replicated using the Asian Screening Array chip, employing data from the Han Chinese Genomes Initiative as controls.

RESULTS

In this study with 771 RLS patients, 645 had primary RLS, and 617 has DNA available for SNP study. Among the 645 primary RLS, 59.7% were women. 33% had a family history of RLS, with stronger familial influence in early-onset cases. Clinical evaluations showed 10.4% had discomfort in body parts other than legs. PSG showed that 57.1% of RLS patients had periodic leg movement index (PLMI) of >5/h and 39.1% had PLMI >15/h, respectively; 73.8% of RLS patients had an Apnea-Hypopnea Index (AHI) > 5/h, and 45.3% had an AHI >15/h. The laboratory examinations revealed serum ferritin levels <75 ng/ml in 31.6%, and transferrin saturation (TSAT) of <45% in 88.7% of RLS patients. Seven new SNPs in 5 genes showed a significant allelic association with Chinese primary RLS, with one previously reported (BTBD9) and four new findings (TOX3, PRMT6, DCDC2C, NOS1).

CONCLUSIONS

Chinese RLS patients has specific characters in many aspects. A high family history with RLS not only indicates strong genetic influence, but also reminds us to consider the familial effect in the epidemiological study. Newly developed sequencing technique with large samples remains to be done.

Prevalence and factors associated with restless legs syndrome among pregnant women in middle-income countries: a systematic review and meta-analysis

Introduction

Restless legs syndrome (RLS) is a debilitating condition characterized by uncomfortable sensations in the legs, typically occurring during periods of rest or sleep. It is more prevalent during pregnancy and is linked to sleep disturbances, diminished quality of life, and pregnancy complications. However, previous studies yielded inconsistent findings among pregnant women in middle-income countries. Consequently, this systematic review and meta-analysis sought to determine the pooled prevalence of restless legs syndrome and its associated factors in these populations.

Method

A systematic review and meta-analysis was conducted on published studies from middle-income countries until May 2023. The review strictly adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relevant search terms were used to search for studies in PubMed, MEDLINE, EMBASE, and Google Scholar. Data extraction was performed using the Joanna Briggs Institute tool for prevalence studies. The meta-analysis was conducted using STATA 17 software, and heterogeneity was assessed using the I2 test, while publication bias was evaluated using Egger's test. Forest plots were also used to present the pooled prevalence and odds ratio (OR) with a 95% confidence interval (CI) using the random-effects model.

Result

This review included 22 studies from nine countries with a total of 17, 580 study participants. The overall pooled prevalence of RLS among pregnant women in middle-income countries was 13.82% (95% CI: 13.31, 14.32), and having low hemoglobin level (AOR: 1.68, 95% CI: 1.29, 2.18), history of RLS (AOR: 7.54, 95% CI: 3.02, 18.79), muscle cramps (AOR: 3.58, 95% CI: 1.21, 10.61), excessive day time sleepiness (AOR: 4.02, 95% CI: 1.34, 12.04), preeclampsia (AOR: 2.06, 95% CI: 1.28, 3.30), and taking prophylactic iron supplementation (AOR: 0.59, 95% CI: 0.50, 0.69) were the identified factors associated with it.

Conclusion

Generally, nearly one in every eight pregnant women in middle-income countries develop restless legs syndrome during pregnancy. Having low hemoglobin level, a history of RLS, muscle cramps, excessive daytime sleepiness, preeclampsia, and taking prophylactic iron supplementation were the identified factors associated with it. These findings underscore the importance of addressing the identified factors associated with RLS in order to effectively mitigate its occurrence among pregnant women.

Prevalence of Current Restless Legs Syndrome Symptoms Among Patients Treated with Buprenorphine/Naloxone for Opioid Use Disorder

Objective

The purpose of this study was to determine the prevalence of Restless Legs Syndrome (RLS) in patients with Opioid Use Disorder (OUD) taking buprenorphine/naloxone maintenance therapy, and to assess symptom frequency, severity, and sleep disruption due to RLS.

Methods

Surveys inquired about demographic information, amount of time on maintenance treatment, previous drug use, current prescribed medications and alcohol use, and RLS symptoms. Participants were determined to have definite, probable, possible, or no RLS symptoms based on pre-established criteria from the Cambridge-Hopkins Questionnaire.

Results

The sample (n=129) was 33.3% female, 81.5% white, and the mean age was 40.6 years (SD=11.9). The median duration of buprenorphine/naloxone use was 3 years. 13.2% of participants had definite/probable RLS symptoms; these symptoms tended to be of moderate severity, occur at least 5-15 times a month, and disrupt sleep to a moderate degree. Of the 17 participants with definite/probable RLS symptoms, just four were taking a medication commonly used to alleviate RLS. An additional 7.0% had possible RLS symptoms.

Conclusion

Relatively high rates of current RLS symptoms were observed; the prevalence of clinically significant RLS was notably higher than that seen in the general population or in previously assessed clinical populations. RLS is common in those acutely withdrawing from opioids, and our data demonstrate that these symptoms are present in a sizable portion of patients on OUD maintenance therapy. Most patients with definite/probable current RLS symptoms did not report taking prescribed medications that have established efficacy for RLS.

Potential therapeutic benefit of spinal cord stimulation in restless legs syndrome: scoping review and mechanistic considerations

BACKGROUND

Restless legs syndrome (RLS) is a prevalent sensorimotor disorder that can dramatically impair sleep quality, daytime function, and quality of life. Although many patients benefit from standard pharmacological therapy, some patients suffer from insufficient treatment response or medication intolerance. Novel treatment approaches are therefore necessary.

OBJECTIVE

Given the overlap between RLS and pain syndromes in both pathophysiological mechanisms and certain treatment options, we aimed to perform a scoping review of the available evidence on spinal cord stimulation (SCS) for RLS and discuss potential mechanistic implications.

METHODS

We identified a total of 16 cases of patients with RLS who underwent SCS, all from case reports or case series.

DISCUSSION

The published evidence is insufficient to assess SCS efficacy in patients with RLS, but SCS remains a promising investigational therapy in RLS on the basis of its potential mitigatory effects in the central hyperexcitability of the sensorimotor cortex through neuromodulation of spinal, subcortical, and cortical areas. A call for further research in this field is presented, with suggestions for future directions and trial designs.

Restless Legs Syndrome and Other Common Sleep-Related Movement Disorders

OBJECTIVE

This article reviews common sleep-related movement disorders, including their clinical description, epidemiology, pathophysiology (if known), and evaluation and management strategies. This article will provide the reader with a good foundation for approaching concerns that are suggestive of sleep-related movement disorders to properly evaluate and manage these conditions.

LATEST DEVELOPMENTS

α2δ Ligands, such as gabapentin enacarbil, can be used for the initial treatment of restless legs syndrome (RLS) or in those who cannot tolerate, or have developed augmentation to, dopamine agonists. Another option is the rotigotine patch, which has a 24-hour treatment window and may be beneficial for those who have developed augmentation with short-acting dopamine agonists. IV iron can improve RLS symptoms even in those whose serum ferritin level is between 75 ng/mL and 100 ng/mL. At serum ferritin levels greater than 75 ng/mL, oral iron will likely have minimal absorption or little effect on the improvement of RLS. Research has found an association between RLS and cardiovascular disease, particularly in people who have periodic limb movements of sleep.

ESSENTIAL POINTS

RLS is the most common sleep-related movement disorder. Its pathophysiology is likely a combination of central iron deficiency, dopamine overproduction, and possibly cortical excitation. Treatment includes oral or IV iron. Dopaminergic medications can be very effective but often lead to augmentation, which limits their long-term use. Other sleep-related movement disorders to be aware of are sleep-related rhythmic movement disorder, nocturnal muscle cramps, sleep-related propriospinal myoclonus, sleep bruxism, and benign myoclonus of infancy.

Restless Legs Syndrome and Periodic Limb Movements of Sleep: From Neurophysiology to Clinical Practice

SUMMARY

This article summarizes restless legs syndrome (RLS), periodic limb movements of sleep, and periodic limb movement disorder. RLS is a common sleep disorder with a prevalence of 5% to 15% in the general population. RLS can present in childhood, and incidence increases with age. RLS can be idiopathic or secondary to iron deficiency, chronic renal failure, peripheral neuropathy, and medications such as antidepressants (with higher rates for mirtazapine and venlafaxine, while bupropion may reduce symptoms at least in the short term), dopamine antagonists (neuroleptic antipsychotic agents and antinausea medications), and possibly antihistamines. Management includes pharmacologic agents (dopaminergic agents, alpha-2 delta calcium channel ligands, opioids, benzodiazepines) and nonpharmacologic therapies (iron supplementation, behavioral management). Periodic limb movements of sleep are an electrophysiologic finding commonly accompanying RLS. On the other hand, most individuals with periodic limb movements of sleep do not have RLS. The clinical significance of the movements has been argued. Periodic limb movement disorder is a distinct sleep disorder that arises in individuals without RLS and is a diagnosis of exclusion.

"Unvoluntary" Movement Disorders: Distinguishing between Tics, Akathisia, Restless Legs, and Stereotypies

Tics, stereotypies, akathisia, and restless legs fall at different places on the spectrum of discrete, unwanted and potentially disabling motor routines. Unlike tremor, chorea, myoclonus, or dystonia, this subgroup of abnormal movements is characterized by the subject's variable ability to inhibit or release undesired motor patterns on demand. Though it may be sometimes clinically challenging, it is crucial to distinguish these "unvoluntary" motor behaviors because secondary causes and management approaches differ substantially. To this end, physicians must consider the degree of repetitiveness of the movements, the existence of volitional control, and the association with sensory symptoms, or cognitive-ideational antecedent. This review aims to summarize the current existing knowledge on phenomenology, diagnosis, and treatment of tics, stereotypies, akathisia, and restless leg syndrome.

Uncovering the mechanism of Radix Paeoniae Alba in the treatment of restless legs syndrome based on network pharmacology and molecular docking

Restless legs syndrome (RLS) is a neurological motor disorder with a high prevalence. The treatment efficacy of RLS is unsatisfactory. Radix Paeoniae Alba (RPA) can effectively treat RLS symptoms such as the discomfort of the legs. RPA has great potential for the development of new medications for RLS. Hence, we explored the mechanism of RPA in the treatment of RLS using network pharmacology and molecular docking. The active components and targets of RPA were obtained from the Traditional Chinese Medicine System Pharmacology database and analysis platform and PharmMapper platform. The RLS-related targets were found in GeneCards, OMIM, DrugBank, and DisGeNET databases. The overlapping targets of RPA and RLS were then collected. The "active components-overlapping targets" network was built, and network topology analysis was performed. Furthermore, Cytoscape 3.9.1 software was used to screen the key components of RPA in the treatment of RLS. Protein-protein interaction was performed using the Search Tool for the Retrieval of Interacting Genes. The gene ontology functions and Kyoto Encyclopedia of Genes and Genomes signaling pathways were analyzed using ClusterProfiler, PathView, and other R packages to reveal the main mechanism of RPA in treating RLS. Component and protein structures were downloaded from the Traditional Chinese Medicine System Pharmacology and Protein Data Bank databases, respectively. The AutoDock 4.2.6 software was used for molecular docking. A total of 12 active components and 109 targets of RPA, as well as 2387 RLS-related targets, were collected. Following that, 47 overlapping targets were obtained. Furthermore, 5 key components and 12 core targets were screened. The results of gene ontology functions were as follows: 2368 biological processes, 264 molecular functions, and 164 cellular components. A total of 207 Kyoto Encyclopedia of Genes and Genomes signaling pathways were obtained, including the lipid and atherosclerosis pathway, the endocrine resistance pathway, the prolactin signaling pathway, and the IL-17 signaling pathway. The components and the core targets completed molecular docking stably. RPA has multi-component, multi-target, and multi-pathway characteristics in treating RLS, which could provide a basis for future research and improve clinical efficacy.

Myoclonus and other jerky movement disorders

Myoclonus and other jerky movements form a large heterogeneous group of disorders. Clinical neurophysiology studies can have an important contribution to support diagnosis but also to gain insight in the pathophysiology of different kind of jerks. This review focuses on myoclonus, tics, startle disorders, restless legs syndrome, and periodic leg movements during sleep. Myoclonus is defined as brief, shock-like movements, and subtypes can be classified based the anatomical origin. Both the clinical phenotype and the neurophysiological tests support this classification: cortical, cortical-subcortical, subcortical/non-segmental, segmental, peripheral, and functional jerks. The most important techniques used are polymyography and the combination of electromyography-electroencephalography focused on jerk-locked back-averaging, cortico-muscular coherence, and the Bereitschaftspotential. Clinically, the differential diagnosis of myoclonus includes tics, and this diagnosis is mainly based on the history with premonitory urges and the ability to suppress the tic. Electrophysiological tests are mainly applied in a research setting and include the Bereitschaftspotential, local field potentials, transcranial magnetic stimulation, and pre-pulse inhibition. Jerks due to a startling stimulus form the group of startle syndromes. This group includes disorders with an exaggerated startle reflex, such as hyperekplexia and stiff person syndrome, but also neuropsychiatric and stimulus-induced disorders. For these disorders polymyography combined with a startling stimulus can be useful to determine the pattern of muscle activation and thus the diagnosis. Assessment of symptoms in restless legs syndrome and periodic leg movements during sleep can be performed with different validated scoring criteria with the help of electromyography.

Consensus guidelines on the construct validity of rodent models of restless legs syndrome

Our understanding of the causes and natural course of restless legs syndrome (RLS) is incomplete. The lack of objective diagnostic biomarkers remains a challenge for clinical research and for the development of valid animal models. As a task force of preclinical and clinical scientists, we have previously defined face validity parameters for rodent models of RLS. In this article, we establish new guidelines for the construct validity of RLS rodent models. To do so, we first determined and agreed on the risk, and triggering factors and pathophysiological mechanisms that influence RLS expressivity. We then selected 20 items considered to have sufficient support in the literature, which we grouped by sex and genetic factors, iron-related mechanisms, electrophysiological mechanisms, dopaminergic mechanisms, exposure to medications active in the central nervous system, and others. These factors and biological mechanisms were then translated into rodent bioequivalents deemed to be most appropriate for a rodent model of RLS. We also identified parameters by which to assess and quantify these bioequivalents. Investigating these factors, both individually and in combination, will help to identify their specific roles in the expression of rodent RLS-like phenotypes, which should provide significant translational implications for the diagnosis and treatment of RLS.

Prevalence, risk factors and effects of restless legs syndrome in COPD patients

Restless legs syndrome (RLS), a sensory motor disorder, is commonly seen amongst chronic obstructive pulmonary disease (COPD) patients. We conducted a study to know its prevalence in COPD and analyse the possible cause and effect of RLS. It is an analytical cross-sectional study conducted between July 2016-December 2020.The prevalence of RLS was evaluated in patients of COPD using RLS diagnostic criteria. Spirometry, iron profile and arterial blood gas analysis was performed in all the patients to evaluate the cause of RLS. The effect was evaluated with diagnostic criteria for insomnia and patient health questionnaire (PHQ2) for depression. There were 205 participants with a mean age of 59±8 years, 182 (88.7%) men and 23 (11.2%) women. The mean body mass index (BMI) was 29±3.9 kg/m2. The prevalence of RLS was 31.2%. RLS was more common amongst women compared to men (60.8% vs 27.4%). RLS was more prevalent among hypoxemic (PaO2<60 mm Hg) and hypercapnic (PaCO2>45 mm Hg) patients (p<0.016; p<0.017). The ROC curve plotted between PaO2 and RLS occurrence showed that the patients having PaO2 less than 76 mm of Hg were more prone to develop RLS. RLS patients had a higher incidence of insomnia as compared to those without RLS (68.8% vs 36.8%, p<0.001). COPD with RLS patients had more depressive symptoms with a higher patient health questionnaire 2 (PHQ2) score (35.9% vs 14.2%, p<0.001) compared to non-RLS COPD patients. The multiple regression analysis also confirmed that RLS led to insomnia and depressive symptoms in COPD patients. To conclude, RLS is common in COPD patients. RLS leads to insomnia and depression, thus should be identified and treated.

Sex Differences in Excessive Daytime Sleepiness Among Patients With Obstructive Sleep Apnea

BACKGROUND AND PURPOSE

To identify sex differences in daytime sleepiness associated with apnea severity and periodic limb movements during sleep (PLMS) in subjects with obstructive sleep apnea (OSA).

METHODS

This study used the Epworth Sleepiness Scale (ESS), Beck Depression Inventory (BDI), and Sleep Hygiene Index (SHI) in logistic regression analyses with interaction terms. Severe OSA, excessive daytime sleepiness (EDS), and PLMS were defined as an apnea-hypopnea index of ≥30, an ESS score of ≥11, and a periodic limb movements index of >15, respectively.

RESULTS

The 1,624 subjects with OSA (males, 79.1%) comprised 45.3%, 38.2%, and 16.4% with severe OSA, EDS, and PLMS, respectively. Multiple logistic regression without interaction terms showed that sex, severe OSA, and PLMS were not significantly associated with EDS. However, significant interactions were noted between sex and severe OSA and PLMS in EDS in both crude and adjusted models (all p values<0.05). In the adjusted model, severe OSA was associated with EDS in males (p=0.009) but not in females. PLMS were more likely to be associated with EDS in females (p=0.013), whereas PLMS were less likely to be associated with EDS in males (p=0.041). The models were adjusted by the BDI score, SHI, and presence of medical comorbidities.

CONCLUSIONS

There are significant sex differences in subjective daytime sleepiness in subjects with severe OSA and PLMS. Severe OSA and PLMS may influence daytime sleepiness more in males and females, respectively.

Restless Legs Syndrome Prevalence and Clinical Correlates Among Psychiatric Inpatients: A Multicenter Study

Background

There are only limited reports on the prevalence of restless legs syndrome (RLS) in patients with psychiatric disorders. The present study aimed to evaluate the prevalence and clinical correlates in psychiatric inpatients in Germany and Switzerland.

Methods

This is a multicenter cross-sectional study of psychiatric inpatients with an age above 18 years that were diagnosed and evaluated face-to-face using the International RLS Study Group criteria (IRLSSG) and the International RLS severity scale (IRLS). In addition to sociodemographic and biometric data, sleep quality and mood were assessed using the Pittsburgh Sleep Quality Index (PSQI), the Insomnia Severity Index (ISI), the Epworth Sleepiness Scale (ESS), and the Patient Health Questionnaire (PHQ-9). In addition to univariate statistics used to describe and statistically analyze differences in variables of interest between patients with and without RLS, a logistic model was employed to identify predictors for the occurrence of RLS.

Results

The prevalence of RLS in a sample of 317 psychiatric inpatients was 16.4%, and 76.9% of these were diagnosed with RLS for the first time. RLS severity was moderate to severe (IRLS ± SD: 20.3 ± 8.4). The prevalences in women (p = 0.0036) and in first-degree relatives with RLS (p = 0.0108) as well as the body mass index (BMI, p = 0.0161) were significantly higher among patients with RLS, while alcohol consumption was significantly lower in the RLS group. With the exception of atypical antipsychotics, treatment with psychotropic drugs was not associated with RLS symptoms. Regarding subjective sleep quality and mood, scores of the PSQI (p = 0.0007), ISI (p = 0.0003), and ESS (p = 0.0005) were higher in patients with RLS, while PHQ-9 scores were not different. A logistic regression analysis identified gender (OR 2.67; 95% CI [1.25; 5.72]), first-degree relatives with RLS (OR 3.29; 95% CI [1.11; 9.73], ESS score (OR 1.09; 95% CI [1.01; 1.17]), and rare alcohol consumption (OR 0.45; 95% CI [0.22; 0.94] as predictors for RLS.

Conclusions

Clinically significant RLS had a high prevalence in psychiatric patients. RLS was associated with higher BMI, impaired sleep quality, and lower alcohol consumption. A systematic assessment of restless legs symptoms might contribute to improve the treatment of psychiatric patients.

No association between plasma hepcidin levels and restless legs syndrome - results from the Danish Blood Donor Study

BACKGROUND

Restless Legs Syndrome (RLS) is a neurological sensorimotor disorder that occurs in the evening and night, thereby often impacting quality of sleep in sufferers. The aetiology of RLS is not completely understood although iron dysregulation has been suggested as a likely pathway. The relationship between RLS and the iron regulatory protein hepcidin has not been studied in large cohorts. We aimed to assess whether an association between plasma hepcidin variation and RLS exists in a large cohort of healthy individuals.

METHODS

Plasma hepcidin levels were measured in 9708 Danish blood donors from the Danish Blood Donor Study all of whom correctly completed the validated Cambridge-Hopkins RLS-questionnaire for RLS assessment.

RESULTS

A total of 466 blood donors were determined as current RLS cases in the sample (4.8%). RLS cases had a significantly higher proportion of females (56.7% vs 46.7%; P < 0.001) and were older (median age [IQR] 40.6 years vs 38.0 years; P = 0.010) than controls. RLS cases were also more frequent smokers (P = 0.004). No significant differences were found in body mass index (BMI), alcohol consumption, time of donation and donation history between cases and controls. No difference in plasma hepcidin levels was observed between RLS cases and controls (median concentration [IQR]: 10.5 ng/ml [6.3-16.4] in RLS cases vs 10.5 ng/ml [6.0-16.5] in controls). Using a logistic regression model, we found that hepcidin levels were not associated with RLS after adjusting for age, sex, alcohol consumption, smoking status, donation time and donation history (OR = 1.00 [0.99-1.02] per 1 ng/ml increase of hepcidin; P = 0.429).

CONCLUSION

Our study in Danish blood donors did not find an association between RLS and plasma hepcidin levels. Our findings suggest that plasma hepcidin's role as a potential diagnostic biomarker of RLS is inadequate.

Restless legs syndrome

Restless legs syndrome (RLS) is a common sensorimotor disorder characterized by an urge to move that appears during rest or is exacerbated by rest, that occurs in the evening or night and that disappears during movement or is improved by movement. Symptoms vary considerably in age at onset, frequency and severity, with severe forms affecting sleep, quality of life and mood. Patients with RLS often display periodic leg movements during sleep or resting wakefulness. RLS is considered to be a complex condition in which predisposing genetic factors, environmental factors and comorbidities contribute to the expression of the disorder. RLS occurs alone or with comorbidities, for example, iron deficiency and kidney disease, but also with cardiovascular diseases, diabetes mellitus and neurological, rheumatological and respiratory disorders. The pathophysiology is still unclear, with the involvement of brain iron deficiency, dysfunction in the dopaminergic and nociceptive systems and altered adenosine and glutamatergic pathways as hypotheses being investigated. RLS is poorly recognized by physicians and it is accordingly often incorrectly diagnosed and managed. Treatment guidelines recommend initiation of therapy with low doses of dopamine agonists or α₂δ ligands in severe forms. Although dopaminergic treatment is initially highly effective, its long-term use can result in a serious worsening of symptoms known as augmentation. Other treatments include opioids and iron preparations.

The prevalence and clinical characteristics of restless legs syndrome in patients with iron deficiency anemia in Korea

STUDY OBJECTIVES

While the prevalence and clinical characteristics of restless legs syndrome (RLS) are known to vary according to ethnicity, a detailed evaluation of this condition among patients with iron deficiency anemia (IDA) has not yet been reported in an Asian population. We investigated the prevalence and clinical characteristics of RLS in patients with IDA in Korea compared with age- and sex-matched patients diagnosed with idiopathic RLS.

METHODS

This prospective single-center study was performed at a regional university hospital. Consecutive patients with IDA were enrolled over a 4-year period. Clinical interviews and laboratory tests were conducted at the first visit. RLS diagnosis was confirmed through face-to-face interviews. We randomly selected patients with idiopathic RLS without comorbid medical disorders from our sleep center dataset as control patients. The clinical characteristics of both groups were compared.

RESULTS

We enrolled 124 patients with IDA. Fifty (40.3%) patients were diagnosed with RLS, with 82% exhibiting severe to very severe symptoms. Patients with IDA and RLS were older and reported more sleep deterioration than patients with IDA without RLS. Patients with IDA and RLS also had a more depressed mood and higher periodic limb movement index scores than patients with idiopathic RLS.

CONCLUSIONS

The prevalence of RLS among patients with IDA in Korea was high, with the majority having severe to very severe symptoms. Patients with IDA and RLS had poorer sleep quality and more emotional problems than patients with IDA without RLS. Therefore, patients with IDA should be screened for RLS to prevent adverse effects on the quality of sleep and life.

The Management of Restless Legs Syndrome: An Updated Algorithm

Restless legs syndrome (RLS) is a common disorder. The population prevalence is 1.5% to 2.7% in a subgroup of patients having more severe RLS with symptoms occurring 2 or more times a week and causing at least moderate distress. It is important for primary care physicians to be familiar with the disorder and its management. Much has changed in the management of RLS since our previous revised algorithm was published in 2013. This updated algorithm was written by members of the Scientific and Medical Advisory Board of the RLS Foundation based on scientific evidence and expert opinion. A literature search was performed using PubMed identifying all articles on RLS from 2012 to 2020. The management of RLS is considered under the following headings: General Considerations; Intermittent RLS; Chronic Persistent RLS; Refractory RLS; Special Circumstances; and Alternative, Investigative, and Potential Future Therapies. Nonpharmacologic approaches, including mental alerting activities, avoidance of substances or medications that may exacerbate RLS, and oral and intravenous iron supplementation, are outlined. The choice of an alpha₂-delta ligand as first-line therapy for chronic persistent RLS with dopamine agonists as a second-line option is explained. We discuss the available drugs, the factors determining which to use, and their adverse effects. We define refractory RLS and describe management approaches, including combination therapy and the use of high-potency opioids. Treatment of RLS in pregnancy and childhood is discussed.

Effects of a 12-week yoga versus a 12-week educational film intervention on symptoms of restless legs syndrome and related outcomes: an exploratory randomized controlled trial

STUDY OBJECTIVES

To assess the effects of a yoga versus educational film (EF) program on restless legs syndrome (RLS) symptoms and related outcomes in adults with RLS.

METHODS

Forty-one community-dwelling, ambulatory nonpregnant adults with moderate to severe RLS were randomized to a 12-week yoga (n = 19) or EF program (n = 22). In addition to attending classes, all participants completed practice/treatment logs. Yoga group participants were asked to practice at home 30 minutes per day on nonclass days; EF participants were instructed to record any RLS treatments used on their daily logs. Core outcomes assessed pretreatment and posttreatment were RLS symptoms and symptom severity (International RLS Study Group Scale (IRLS) and RLS ordinal scale), sleep quality, mood, perceived stress, and quality of life (QOL).

RESULTS

Thirty adults (13 yoga, 17 EF), aged 24 to 73 (mean = 50.4 ± 2.4 years), completed the 12-week study (78% female, 80.5% white). Post-intervention, both groups showed significant improvement in RLS symptoms and severity, perceived stress, mood, and QOL-mental health (P ≤ .04). Relative to the EF group, yoga participants demonstrated significantly greater reductions in RLS symptoms and symptom severity (P ≤ .01), and greater improvements in perceived stress and mood (P ≤ .04), as well as sleep quality (P = .09); RLS symptoms decreased to minimal/mild in 77% of yoga group participants, with none scoring in the severe range by week 12, versus 24% and 12%, respectively, in EF participants. In the yoga group, IRLS and RLS severity scores declined with increasing minutes of homework practice (r = .7, P = .009 and r = .6, P = .03, respectively), suggesting a possible dose-response relationship.

CONCLUSIONS

Findings of this exploratory RCT suggest that yoga may be effective in reducing RLS symptoms and symptom severity, decreasing perceived stress, and improving mood and sleep in adults with RLS.

CLINICAL TRIAL REGISTRATION

Registry: Clinicaltrials.gov; Title: Yoga vs. Education for Restless Legs: a Feasibility Study; Identifier: NCT03570515; URL: https://clinicaltrials.gov/ct2/show/NCT03570515.

Idiopathic and secondary restless legs syndrome during pregnancy in Japan: Prevalence, clinical features and delivery-related outcomes

Objective

The aim of this study was to investigate prevalence of idiopathic and secondary restless legs syndrome (RLS) according to pregnancy trimester, and its effects on delivery-related outcomes among pregnant women in Japan.

Methods

This was a single-center, prospective observational study. One hundred eighty-two consecutive pregnant women participated in the study from June 2014 to March 2016. Participants were interviewed and examined in the second and third trimesters of pregnancy and 1 month after delivery. At each term, RLS was identified by a research assistant and then specialist in sleep medicine based on the diagnostic criteria of the International Restless Legs Syndrome Study Group. Delivery-related data was collected from medical charts. RLS was classified as idiopathic RLS, which originally existed before the index pregnancy, or secondary RLS, which newly appeared during the index pregnancy.

Results

The prevalence of RLS was 4.9% (idiopathic 3.3%, secondary 1.6%) in the second trimester, 5.0% (idiopathic 0.0%, secondary 5.0%) in the third trimester, and 0.6% (idiopathic 0.0%, secondary 0.6%) after delivery. Prolonged labor, emergency Cesarean section, and arrest of labor tended to be more frequent in idiopathic and/or second RLS (all p<0.05).

Conclusions

The prevalence of RLS during pregnancy was 4–5% and decreases after delivery in current Japan. The presence of RLS was associated with an increase in some delivery-related outcomes. Early detection and treatment of RLS during pregnancy may be beneficial to safe delivery for pregnant women.

The Long-Term Psychiatric and Cardiovascular Morbidity and Mortality of Restless Legs Syndrome and Periodic Limb Movements of Sleep

Restless legs syndrome (RLS) is a sensory-motor neurological disorder that is associated with high levels of distress and sleep disturbance. Cross-sectional and longitudinal evidence suggests that individuals suffering from RLS may be at an increased risk of certain psychiatric illnesses and cardiovascular diseases. There also is evidence for increased mortality rates in RLS patients, although contrasting results do exist. Periodic limb movements of sleep (PLMS), repetitive leg movement observed in most RLS patients, and sleep disturbance may mediate the relationship between RLS and long-term morbidity. This article summarizes the literature investigating the potential consequences of both RLS and PLMS.

[Restless legs syndrome]

Restless legs syndrome (RLS) is seen widely in clinical practice. RLS commonly occurs at night time and presents with unpleasant or uncomfortable sensations in the legs that causes an urge to move them. This article describes the epidemiology, risk factors and pathophysiology of RLS. There is a detailed description of clinical presentations, diagnostic criteria and also management of RLS.

We need to do better: A systematic review and meta-analysis of diagnostic test accuracy of restless legs syndrome screening instruments

This systematic review and meta-analysis evaluated the diagnostic accuracy of screening instruments for restless legs syndrome (RLS) and reports sensitivity, specificity, positive (PPV) and negative predictive values (NPV). Searches for primary studies were conducted in electronic databases. Of the 1541 citations identified, 52 were included in the meta-analysis. The methodological quality of each study was evaluated using QUADAS-2. Only 14 studies assessed the reference standard in all participants or in all screen-positives and a selection of screen-negatives. Bivariate meta-analysis of these 14 studies estimated median sensitivity to be 0.88 (0.72-0.96) and specificity 0.90 (0.84-0.93); based on a population prevalence of 5%, the calculated PPV was 0.31 (0.27-0.34). For all 52 studies, with either full or partial verification of RLS status, we constructed best-case scenario sensitivities and specificities at pre-defined levels of prevalence: across all samples, when prevalence is 5%, the median best-case scenario PPV is 0.48 with significant between-study heterogeneity. No RLS screening instruments can currently be recommended for use without an expert clinical interview in epidemiological studies. For conditions with statistically low prevalence such as RLS, the specificity, not the sensitivity, of a screening instrument determines true prevalence. Therefore, future instruments should maximize specificity. We provide guidelines on RLS ascertainment in epidemiological studies that requires a two-step process with clinical interview following a screening test, and given the poor reporting quality of many RLS epidemiological studies, we include an RLS reporting checklist.

Grey matter alterations in restless legs syndrome: A coordinate-based meta-analysis

Brain structural abnormalities in idiopathic restless legs syndrome have long been debated. Voxel-based morphometry is an objective structural magnetic resonance imaging technique to investigate regional grey matter volume or density differences between groups. In the last decade, voxel-based morphometry studies have exhibited inconsistent and conflicting findings regarding the presence and localization of brain grey matter alterations in restless legs syndrome. We therefore conducted a coordinate-based meta-analysis to quantitatively examine whether there were consistent grey matter findings in restless legs syndrome using the latest algorithms, seed-based d mapping with permutation of subject images. We included 12 voxel-based morphometry studies (13 datasets, 375 patients and 385 healthy controls). Our coordinate-based meta-analysis did not identify evidence of consistent grey matter alterations in restless legs syndrome. Grey matter alterations via voxel-based morphometry analysis are not therefore recommended to be used as a reliable surrogate neuroimaging marker for restless legs syndrome. This lack of consistency may be attributed to differences in sample size, genetics, gender distribution and age at onset, clinical heterogeneity (clinical course, anatomical distribution of symptoms, disease severity, disease duration, abnormal sensory profiles and comorbidity), and variations in imaging acquisition, data processing and statistical strategies. Longitudinal studies with multimodal neuroimaging techniques are needed to determine whether structural changes are dynamic and secondary to functional abnormalities.

A follow-up study on restless legs syndrome in chronic obstructive pulmonary disease population

BACKGROUND

Restless legs syndrome (RLS) is prevalent in patients with chronic obstructive pulmonary disease (COPD). No large population-based cohort study has assessed the relationship. We evaluated the incidence of RLS among COPD patients by sociodemographic status (SES) and comorbidity using insurance claims data of Taiwan.

METHODS

From the database, we established a cohort consisting of 77,831 individuals aged ≥ 20 years newly diagnosed with COPD from 2000 to 2013. We also identified same number of individuals without COPD as the comparison cohort, frequency matched by sex, age and index year. Both cohorts were followed up to the end of 2013 to estimate the incidence and hazard ratio (HR) of developing RLS.

RESULTS

The incidence of RLS was 2.2-fold higher in COPD patients than in those free of COPD (6.67 and 3.08 per 10,000 person-years), with an adjusted HR (aHR) 1.68 (95% CI 1.41-2.01) after controlling for covariates. The incidence rates in both cohorts increased with age and higher in low socioeconomic group. The risk of RLS increased further among COPD patients with additional comorbidities. Compared to those without COPD and comorbidity, the aHR was 7.93 (95% CI 1.11-57.8) for those with iron deficiency, 3.95 (96% CI 1.92-8.13) with Parkinson's disease, 2.85 (95% CI 1.05-7.72) with polyneuropathy, or 1.81 (95% CI 1.14-2.87) with diabetes.

CONCLUSION

Patients with COPD are at an increased risk of developing RLS regardless of gender, age and occupation. The COPD patients with comorbidities should be particularly cautious about the RLS risk.

Effects of menopause on sleep quality and sleep disorders: Canadian Longitudinal Study on Aging

OBJECTIVES

Sleep complaints are common during the menopause transition. However, it is difficult to disentangle changes in sleep related to aging from those directly due to menopause. We compared sleep disorders in 45 to 60-year-old women in a large population-based study, according to menopausal status.

METHODS

Women aged between 45 and 60 years who self-reported menopausal status were selected from the Canadian Longitudinal Study of Aging, excluding those with prior hysterectomy. Participants completed assessments for overall sleep satisfaction, hours of daily sleep, sleep-onset insomnia, sleep-maintenance insomnia, daytime somnolence, rapid eye movement sleep behavior disorder (RBD), restless leg syndrome (RLS), and obstructive sleep apnea (OSA). Each sleep variable was compared between postmenopausal and pre/perimenopausal women using multivariate regression, adjusting for potential confounders.

RESULTS

Among 6,179 women included, 3,713 (60.1%; age 55.7 ± 3.3 years) were postmenopausal and 2,466 (39.9%) were pre/perimenopausal (age 49.80 ± 3.1 years). Compared with pre/perimenopausal women, postmenopausal women were more often reported requiring ≥30 minutes to fall asleep (20.4% vs 15.5%; adjusted odds ratio [AOR] 1.24, 95% confidence interval [CI] 1.00-1.53) and were more likely to meet criteria for possible sleep-onset insomnia disorder (10.8% vs 7.3%; AOR 1.51, 95% CI 1.07-2.12). Postmenopausal women were also more likely to screen positive for OSA (14.6% vs 10.4%; AOR 1.48, 95% CI 1.14-1.92). The two groups did not differ on sleep dissatisfaction (32.4% vs 29%), daytime somnolence disorder (1.6% vs 1.3%), sleep-maintenance insomnia disorder (17% vs 14.5%), RLS (23.5% vs 20.9%), or RBD (3.9% vs 4.0%).

CONCLUSIONS

Menopause is associated with increased sleep-onset insomnia. Postmenopausal women also are more likely to screen positive for OSA. However, menopausal status is not associated with sleep maintenance, somnolence, or RLS, and RBD. : Video Summary:http://links.lww.com/MENO/A501.

Nighttime Agitation in Persons with Dementia as a Manifestation of Restless Legs Syndrome

OBJECTIVES

Nighttime agitation or "sundowning" is challenging for clinicians and caregivers to manage in older adults in the dementia stage of Alzheimer's disease (AD-D). Our research previously revealed that nighttime agitation might be a manifestation of restless legs syndrome (RLS). The current study aims to describe the characteristics of older adults with AD-D, nighttime agitation, and RLS, and to evaluate sleep disturbance and iron status in relation to nighttime agitation severity.

DESIGN

An observational study with baseline descriptive and correlational data from a clinical trial.

SETTING AND PARTICIPANTS

Long-term care (n = 69) and independent living (n = 7); age 82.91 ± 9.46 years, with AD-D, nighttime agitation, and RLS.

MEASUREMENTS

Trained observers counted nighttime agitation behaviors. Independent variables were age; cognition measured by the Mini-Mental State Examination; minutes slept from actigraphy; transferrin saturation percentage (TS%) and transferrin from fasting blood samples; and illness severity using the Cumulative Illness Rating Scale for Geriatrics. Bivariate and multivariable linear regression models were generated.

RESULTS

In the multivariable model, sleep minutes (P = .002) and TS% (P = .003) were negatively associated with frequency of nighttime agitation behaviors, and they explained 20% of the variance. Seventy-nine percent received 1 or more medications that worsen RLS symptoms, such as antihistamines and serotonin reuptake inhibitors.

CONCLUSIONS AND IMPLICATIONS

We encourage clinicians to consider nighttime agitation as a manifestation of RLS. Treatment of iron deficiency indicated by low TS% and deprescribing medications that exacerbate RLS may decrease nighttime agitation, improve sleep, and enhance quality of life in older adults with AD-D.

Large genome-wide association study identifies three novel risk variants for restless legs syndrome

Restless legs syndrome (RLS) is a common neurological sensorimotor disorder often described as an unpleasant sensation associated with an urge to move the legs. Here we report findings from a meta-analysis of genome-wide association studies of RLS including 480,982 Caucasians (cases = 10,257) and a follow up sample of 24,977 (cases = 6,651). We confirm 19 of the 20 previously reported RLS sequence variants at 19 loci and report three novel RLS associations; rs112716420-G (OR = 1.25, P = 1.5 × 10-18), rs10068599-T (OR = 1.09, P = 6.9 × 10-10) and rs10769894-A (OR = 0.90, P = 9.4 × 10-14). At four of the 22 RLS loci, cis-eQTL analysis indicates a causal impact on gene expression. Through polygenic risk score for RLS we extended prior epidemiological findings implicating obesity, smoking and high alcohol intake as risk factors for RLS. To improve our understanding, with the purpose of seeking better treatments, more genetics studies yielding deeper insights into the disease biology are needed.

Acupuncture and related techniques for restless legs syndrome: A protocol for systematic review and meta-analysis

BACKGROUND

Restless legs syndrome (RLS) is a common sensory disorder of the nervous system, which often affects the sleep quality of patients. Acupuncture and related techniques are increasingly used to treat neurological diseases, but their efficacy and safety for RLS are yet to be established. The purpose of this study is to summarize the effectiveness and safety of acupuncture and related techniques for RLS.

METHODS

We will conduct a comprehensive data retrieval, and the electronic databases will include PubMed, Embase, Cochrane Library, WangFang Database, China National Knowledge Infrastructure, Chinese Scientific Journal Database, Chinese Biomedical Literature Database, from establishment to October 2020. We will also manually search unpublished studies and references, and contact lead authors. Randomized clinical trials (RCTs) of acupuncture and related techniques for RLS will be included. The outcomes of interest include: The total effective rate and International Restless Leg Syndrome rating scale (IRLS), Pittsburgh Sleep Quality Index (PSQI), Hamilton Anxiety Scale (HAMA), Hamilton Depression Scale (HAMD), adverse events, quality of life. To assess the methodological quality, we will use the Cochrane risk assessment tool. RevMan 5.3.5 software will be used to conduct data synthesis. The evidence quality of each outcome will be appraised according to Grades of Recommendation, Assessment, Development, and Evaluation (GRADE).

RESULTS

The results will be published in a peer-reviewed journal.

CONCLUSION

This study will provide a high-quality evidence to evaluate the efficacy and adverse reactions of acupuncture and related techniques for RLS.

PROSPERO REGISTRATION NUMBER

CRD42020157957.

The Effect of Parenteral or Oral Iron Supplementation on Fatigue, Sleep, Quality of Life and Restless Legs Syndrome in Iron-Deficient Blood Donors: A Secondary Analysis of the IronWoMan RCT

Background: Besides anemia, iron deficiency may cause more subtle symptoms, including the restless legs syndrome (RLS), the chronic fatigue syndrome (CFS) or sleeping disorders. Objective: The aim of this pre-planned secondary analysis of the IronWoMan randomized controlled trial (RCT) was to compare the frequency and severity of symptoms associated with iron deficiency before and after (intravenous or oral) iron supplementation in iron deficient blood donors. Methods/Design: Prospective, randomized, controlled, single-centre trial. (ClinicalTrials.gov: NCT01787526). Setting: Tertiary care center in Graz, Austria. Participants: 176 (138 female and 38 male) whole-blood and platelet apheresis donors aged ≥ 18 and ≤ 65 years with iron deficiency (ferritin ≤ 30ng/mL at the time of blood donation). Interventions: Intravenous iron (1 g ferric carboxymaltose, n = 86) or oral iron supplementation (10 g iron fumarate, 100 capsules, n = 90). Measurements: Clinical symptoms were evaluated by a survey before iron therapy (visit 0, V0) and after 8–12 weeks (visit 1, V1), including questions about symptoms of restless legs syndrome (RLS), chronic fatigue syndrome (CFS), sleeping disorders, quality of life and symptoms like headaches, dyspnoea, dizziness, palpitations, pica and trophic changes in fingernails or hair. Results: We found a significant improvement in the severity of symptoms for RLS, fatigue and sleep quality (p < 0.001). Furthermore, a significant decrease in headaches, dyspnoea, dizziness and palpitations was reported (p < 0.05). There was no difference between the type of iron supplementation (intravenous versus oral) and clinical outcome data. Conclusion: Iron supplementation in iron-deficient blood donors may be an effective strategy to improve symptoms related to iron deficiency and the wellbeing of blood donors.

Prevalence and Risk Factors of Restless Legs Syndrome in Hemodialysis Patients

OBJECTIVE

The current study aimed to investigate the prevalence and risk factors of restless legs syndrome (RLS) in patients undergoing hemodialysis, as well as the mortality and risks of cardiovascular and cerebrovascular events.

METHODS

A total of 354 hemodialysis patients from four hospitals were enrolled. RLS was diagnosed using the International RLS Study Group (IRLSSG) criteria. The patients were evaluated face-to-face using the IRLSSG rating scale, Epworth Sleepiness Scale (ESS), Hamilton Anxiety Scale, Hamilton Depression Scale, and Pittsburgh Sleep Quality Index (PSQI). The patients were followed up for 9 months. Death was considered an endpoint event. The cardiovascular and cerebrovascular events were investigated.

RESULTS

The prevalence of RLS in hemodialysis patients was 40.7% and was associated with factors such as duration of hemodialysis, hypersensitive C-reactive protein, hyperparathyroidism, glycosylated serum protein, and erythropoietin treatment. The scores of the PSQI, ESS, and Hamilton Depression Scale in the RLS group were significantly higher than those in the non-RLS group (p < 0.05). During follow-ups, the incidence rate of cardiovascular diseases was 18.8% in the RLS group and 8.6% in the non-RLS group (p < 0.005). The IRLSSG rating scores were significantly higher in RLS patients with kidney transplantation failure compared with those without transplantation (p < 0.05).

CONCLUSION

The prevalence of RLS was high in hemodialysis patients. The risk factors of RLS included duration of hemodialysis, hypersensitive C-reactive protein, hyperparathyroidism, glycosylated serum protein, and erythropoietin treatment. RLS affected sleep quality and emotion and increased the risk of cardiovascular diseases in hemodialysis patients. RLS was more severe in patients with kidney transplantation failure compared with those without transplantation.

Effect of Cognitive Behavioral Therapy for Insomnia on Insomnia Symptoms for Individuals With Type 2 Diabetes: Protocol for a Pilot Randomized Controlled Trial

Background

Insomnia symptoms are a common form of sleep difficulty among people with type 2 diabetes (T2D) affecting sleep quality and health outcomes. Several interventional approaches have been used to improve sleep outcomes in people with T2D. Nonpharmacological approaches, such as cognitive behavioral therapy for insomnia (CBT-I), show promising results regarding safety and sustainability of improvements, although CBT-I has not been examined in people with T2D. Promoting sleep for people with insomnia and T2D could improve insomnia severity and diabetes outcomes.

Objective

The objective of this study is to establish a protocol for a pilot randomized controlled trial (RCT) to examine the effect of 6 sessions of CBT-I on insomnia severity (primary outcome), sleep variability, and other health-related outcomes in individuals with T2D and insomnia symptoms.

Methods

This RCT will use random mixed block size randomization with stratification to assign 28 participants with T2D and insomnia symptoms to either a CBT-I group or a health education group. Outcomes including insomnia severity; sleep variability; diabetes self-care behavior (DSCB); glycemic control (A_1c); glucose level; sleep quality; daytime sleepiness; and symptoms of depression, anxiety, and pain will be gathered before and after the 6-week intervention. Chi-square and independent t tests will be used to test for between-group differences at baseline. Independent t tests will be used to examine the effect of the CBT-I intervention on change score means for insomnia severity, sleep variability, DSCB, A_1c, fatigue, sleep quality, daytime sleepiness, and severity of depression, anxiety, and pain. For all analyses, alpha level will be set at .05.

Results

This study recruitment began in February 2019 and was completed in September 2019.

Conclusions

The intervention, including 6 sessions of CBT-I, will provide insight about its effect in improving insomnia symptoms, sleep variability, fatigue, and diabetes-related health outcomes in people with T2D and those with insomnia symptoms when compared with control.

Trial Registration

ClinicalTrials.gov NCT03713996; https://clinicaltrials.gov/ct2/show/NCT03713996

International Registered Report Identifier (IRRID)

DERR1-10.2196/14647

Time evolution of restless legs syndrome in haemodialysis patients

Background

Restless legs syndrome (RLS) is characterized by an urge to move the extremities, accompanied by paraesthesiae, in the evening and at night. Uraemic RLS, a type of secondary RLS, occurs commonly in chronic kidney disease and end-stage renal disease. Progression of uraemic RLS over time is unclear. Therefore we investigated the prevalence, progression over time, risk factors and impact on survival of uraemic RLS in a cohort of dialysis patients.

Methods

We reviewed at the 7-year follow-up a cohort of haemodialysis (HD) patients we had previously investigated for RLS, through interviews, validated questionnaires and analysis of demographic and clinical data.

Results

At the 7-year follow-up, RLS was present in 16% of patients, with a persistence rate of 33%. A correlation was obtained between RLS and older age, diabetes, low albumin and low body mass index. RLS was associated with reduced overall survival (median survival of 3.3 versus 3.7 years), particularly with the continuous form of RLS (1.61 years). There was a higher incidence of myocardial infarction and peripheral vascular disease, although not reaching statistical significance. RLS patients had absolute higher scores in all quality of life domains. A large majority of study patients (96%) reported being symptom-free within a few days or weeks following kidney transplantation.

Conclusions

The development of RLS, especially the continuous form, in patients undergoing HD has important consequences associated with decreased survival. Our results indicated an association between uraemic RLS and ageing, diabetes and malnutrition. Considerable efforts should be focused on the treatment of RLS, since it significantly and persistently impacts the quality of life of HD patients. Kidney transplantation could represent an effective treatment option for that RLS impacts on dialysis patients' quality of life, thus confirming the secondary nature of RLS in most HD patients.

Reassessing GWAS findings for the shared genetic basis of insomnia and restless legs syndrome

Two genome-wide association studies (GWAS) suggest that insomnia and restless legs syndrome (RLS) share a common genetic basis. While the identified genetic variation in the MEIS1 gene was previously associated with RLS, the two GWAS suggest a novel and independent association with insomnia symptoms. To test the potential pleiotropic effect of MEIS1, we genotyped three MEIS1 variants in 646 chronic insomnia disorder (CID) patients with and without RLS. To confirm our results, we compared the allelic and genotypic distributions of the CID cohort with ethnically matched controls and RLS cases in the French Canadian cohort. The CID cohort was diagnosed by sleep medicine specialists and 26% of the sample received the combined diagnosis of CID+RLS. We find significant differences in allele and genotype distributions between CID-only and CID+RLS groups, suggesting that MEIS1 is only associated with RLS. Genotype distributions and minor allele frequencies of the three MEIS1 SNPs of the CID-only and control groups were similar (rs113851554: 5.3% vs. 5.6%; rs2300478: 25.3% vs. 26.5%; rs12469063: 23.6% vs. 24.4%; all p > 0.05). Likewise, there were no differences between CID+RLS and RLS-only groups (all p > 0.05). In conclusion, our data confirms that MEIS1 is a genetic risk factor for the development of RLS, but it does not support the pleiotropic effect of MEIS1 in CID. While a lack of power precluded us from refuting small pleiotropic effects, our findings emphasize the critical importance of isolating CID from other disorders that can cause sleep difficulties, particularly RLS, for future genetic studies.

Functional and Neuroprotective Role of Striatal Adenosine A2A Receptor Heterotetramers

In the striatum, adenosine A_2A receptors (A_2AR) are mainly expressed within the soma and dendrites of the striatopallidal neuron. A predominant proportion of these striatal postsynaptic A_2AR form part of the macromolecular complexes that include A_2AR-dopamine D₂ receptor (D₂R) heteromers, G_olf and G_i/o proteins, and the effector adenylyl cyclase (AC), subtype AC5. The A_2AR-D₂R heteromers have a tetrameric structure, constituted by A_2AR and D₂R homomers. By means of reciprocal antagonistic allosteric interactions and antagonistic interactions at the effector level between adenosine and dopamine, the A_2AR-D₂R heterotetramer-AC5 complex acts an integrative molecular device, which determines a switch between the adenosine-facilitated activation and the dopamine-facilitated inhibition of the striatopallidal neuron. Striatal adenosine also plays an important presynaptic modulatory role, driving the function of corticostriatal terminals. This control is mediated by adenosine A₁ receptors (A₁R) and A_2AR, which establish intermolecular interactions forming A₁R-A_2AR heterotetramers. Here, we review the functional role of both presynaptic and postsynaptic striatal A_2AR heterotetramers as well as their possible neuroprotective role. We hypothesize that alterations in the homomer/heteromer stoichiometry (i.e., increase or decrease in the proportion of A_2AR forming homomers or heteromers) are pathogenetically involved in neurological disorders, specifically in Parkinson's disease and restless legs syndrome.

Reporting Quality of Randomized Controlled Trials in Restless Legs Syndrome Based on the CONSORT Statement

Background

Randomized controlled trials (RCTs) are the cornerstone of modern medical research, and their reporting may not always be optimal. The Consolidated Standards of Reporting Trials (CONSORT) statement is an evidence-based means to improve the quality of RCTs’ reporting by providing a checklist of recommended items.

The aim of this study was to assess the reporting quality of published RCTs on the restless legs syndrome (RLS), based on a checklist arising from the CONSORT statement.

Methods

Medical electronic databases were searched for RCTs involving patients with RLS. Inclusion criteria were follows: articles must have been published in English and RLS patients must have been randomized into a minimum of two treatment cohorts of different medicinal orientations. CONSORT-recommended items were marked as “reported” or “not reported,” and an overall CONSORT compliance metric was calculated. Comparisons among different time periods, CONSORT-endorsing and non-endorsing, and different levels of impact factor journals were made.

Results

Fifty-four eligible trials, published in 21 different scientific journals, were found. The average CONSORT compliance score was 56.6% (23.68–84.21%). CONSORT-endorsing journals had a mean CONSORT compliance of 58.47%, whereas non-endorsing journals had a mean CONSORT compliance of 50.4%. The median CONSORT compliance for articles published in low- (IF<2), medium- (IF 2-7), and high-ranked (IF>7) journals was 52.63, 56.57, and 59.21%, respectively. Only 14 of the 38 CONSORT items (36.8%) were reported in >75% of the articles.

Discussion

This study shows that the reporting of RLS-related RCTs is suboptimal, regardless of the time period, the quality of the publishing journal, and the endorsing or non-endorsing of the CONSORT statement.

Acceptability and feasibility of a 12-week yoga vs. educational film program for the management of restless legs syndrome (RLS): study protocol for a randomized controlled trial

Background

Restless legs syndrome (RLS) is a common and burdensome sleep disorder associated with profound impairment of health, well-being, and quality of life. Unfortunately, the medications used for RLS management carry risk of serious side effects, including augmentation of symptoms. Yoga, an ancient mind-body discipline designed to promote physical, emotional, and mental well-being, may offer a viable, low-risk new treatment. The primary objectives of this pilot, parallel-arm, randomized controlled trial (RCT) are to assess the acceptability and feasibility of a 12-week yoga vs. educational film program for the management of RLS.

Methods

Forty-four adults with confirmed moderate to severe RLS will be recruited and randomized to a 12-week yoga (n = 22) or standardized educational film program (N = 22). Yoga group participants will attend two 75-min Iyengar yoga classes per week for the first 4 weeks, then one 75-min class per week for the remaining 8 weeks, and will complete a 30-min homework routine on non-class days. Educational film group participants will attend one 75-min class per week for 12 weeks and complete a daily RLS treatment log; classes will include information on: RLS management, including sleep hygiene practices; other sleep disorders; and complementary therapies likely to be of interest to those participating in a yoga and sleep education study.

Yoga and treatment logs will be collected weekly. Feasibility outcomes will include recruitment, enrollment, and randomization rates, retention, adherence, and program satisfaction. Program evaluation and yoga-dosing questionnaires will be collected at week 12; data on exploratory outcomes (e.g., RLS symptom severity (IRLS), sleep quality (PSQI), mood (POMS, PSS), and health-related quality of life (SF-36)) will be gathered at baseline and week 12.

Discussion

This study will lay the essential groundwork for a planned larger RCT to determine the efficacy of a yoga program for reducing symptoms and associated burden of RLS. If the findings of the current trial and the subsequent larger RCTs are positive, this study will also help support a new approach to clinical treatment of this challenging disorder, help foster improved understanding of RLS etiology, and ultimately contribute to reducing the individual, societal, and economic burden associated with this condition.

Trial registration

ClinicalTrials.gov, ID: NCT03570515. Retrospectively registered on 1 February 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3217-7) contains supplementary material, which is available to authorized users.

The heterotetrameric structure of the adenosine A1-dopamine D1 receptor complex: Pharmacological implication for restless legs syndrome

Dopaminergic and purinergic signaling play a pivotal role in neurological diseases associated with motor symptoms, including Parkinson's disease (PD), multiple sclerosis, amyotrophic lateral sclerosis, Huntington disease, Restless Legs Syndrome (RLS), spinal cord injury (SCI), and ataxias. Extracellular dopamine and adenosine exert their functions interacting with specific dopamine (DR) or adenosine (AR) receptors, respectively, expressed on the surface of target cells. These receptors are members of the family A of G protein-coupled receptors (GPCRs), which is the largest protein superfamily in mammalian genomes. GPCRs are target of about 40% of all current marketed drugs, highlighting their importance in clinical medicine. The striatum receives the densest dopamine innervations and contains the highest density of dopamine receptors. The modulatory role of adenosine on dopaminergic transmission depends largely on the existence of antagonistic interactions mediated by specific subtypes of DRs and ARs, the so-called A_2AR-D₂R and A₁R-D₁R interactions. Due to the dopamine/adenosine antagonism in the CNS, it was proposed that ARs and DRs could form heteromers in the neuronal cell surface. Therefore, adenosine can affect dopaminergic signaling through receptor-receptor interactions and by modulations in their shared intracellular pathways in the striatum and spinal cord. In this work we describe the allosteric modulations between GPCR protomers, focusing in those of adenosine and dopamine within the A₁R-D₁R heteromeric complex, which is involved in RLS. We also propose that the knowledge about the intricate allosteric interactions within the A₁R-D₁R heterotetramer, may facilitate the treatment of motor alterations, not only when the dopamine pathway is hyperactivated (RLS, chorea, etc.) but also when motor function is decreased (SCI, aging, PD, etc.).

Periodic limb movements in sleep: Prevalence and associated sleepiness in the Wisconsin Sleep Cohort

OBJECTIVES

Periodic limb movements in sleep (PLMS) are thought to be prevalent in elderly populations, but their impact on quality of life remains unclear. We examined the prevalence of PLMS, impact of age on prevalence, and association between PLMS and sleepiness.

METHODS

We identified limb movements in 2335 Wisconsin Sleep Cohort polysomnograms collected over 12 years. Prevalence of periodic limb movement index (PLMI) ≥15 was calculated at baseline (n = 1084). McNemar's test assessed changes in prevalence over time. Association of sleepiness and PLMS evaluated using linear mixed modeling and generalized estimating equations. Models adjusted for confounders.

RESULTS

Prevalence of PLMI ≥15 at baseline was 25.3%. Longitudinal prevalence increased significantly with age (p = 2.97 × 10^-14). Sleepiness did not differ significantly between PLMI groups unless stratified by restless legs syndrome (RLS) symptoms. The RLS+/PLM+ group was sleepier than the RLS+/PLM- group. Multiple Sleep Latency Test trended towards increased alertness in the RLS-/PLM+ group compared to RLS-/PLM-.

CONCLUSIONS

A significant number of adults have PLMS and prevalence increased with age. No noteworthy association between PLMI category and sleepiness unless stratified by RLS symptoms.

SIGNIFICANCE

Our results indicate that RLS and PLMS may have distinct clinical consequences and interactions that can help guide treatment approach.

A direct interaction between two Restless Legs Syndrome predisposing genes: MEIS1 and SKOR1

Restless Legs syndrome (RLS) is a common sleep disorder for which the genetic contribution remains poorly explained. In 2007, the first large scale genome wide association study (GWAS) identified three genomic regions associated with RLS. MEIS1, BTBD9 and MAP2K5/SKOR1 are the only known genes located within these loci and their association with RLS was subsequently confirmed in a number of follow up GWAS. Following this finding, our group reported the MEIS1 risk haplotype to be associated with its decreased expression at the mRNA and protein levels. Here we report the effect of the risk variants of the three other genes strongly associated with RLS. While these variants had no effect on the mRNA levels of the genes harboring them, we find that the homeobox transcription factor MEIS1 positively regulates the expression of the transcription co-repressor SKOR1. This regulation appears mediated through the binding of MEIS1 at two specific sites located in the SKOR1 promoter region and is modified by an RLS associated SNP in the promoter region of the gene. Our findings directly link MEIS1 and SKOR1, two significantly associated genes with RLS and also prioritize SKOR1 over MAP2K5 in the RLS associated intergenic region of MAP2K5/SKOR1 found by GWAS.

New Insights into the Neurobiology of Restless Legs Syndrome

Restless legs syndrome (RLS) is a common sensorimotor disorder, whose basic components include a sensory experience, akathisia, and a sleep-related motor sign, periodic leg movements during sleep (PLMS), both associated with an enhancement of the individual's arousal state. The present review attempts to integrate the major clinical and experimental neurobiological findings into a heuristic pathogenetic model. The model also integrates the recent findings on RLS genetics indicating that RLS has aspects of a genetically moderated neurodevelopmental disorder involving mainly the cortico-striatal-thalamic-cortical circuits. Brain iron deficiency (BID) remains the key initial pathobiological factor and relates to alterations of iron acquisition by the brain, also moderated by genetic factors. Experimental evidence indicates that BID leads to a hyperdopaminergic and hyperglutamatergic states that determine the dysfunction of cortico-striatal-thalamic-cortical circuits in genetically vulnerable individuals. However, the enhanced arousal mechanisms critical to RLS are better explained by functional changes of the ascending arousal systems. Recent experimental and clinical studies suggest that a BID-induced hypoadenosinergic state provides the link for a putative unified pathophysiological mechanism for sensorimotor signs of RLS and the enhanced arousal state.

Restless Legs Syndrome and Poor Sleep Quality in Obese Children and Adolescents

OBJECTIVE

Adult epidemiological studies suggest that the rate of Restless Legs syndrome (RLS) in the general population may range from 5% to 15%. The aim of this study was to investigate the frequency of RLS in a community sample of obese adolescents aged 10-16 years and to assess the association with sleep quality and health-related glucose metabolism markers.

METHODS

The study group comprised 144 obese and overweight children aged 10-16 yearsand the control group consisted of 66 age-matched healthy children. The RLS Questionnaire devised by the International RLS Study and the Pittsburgh Sleep Quality Index (PSQI), where a score >5 indicates poor sleep quality, was used to assess sleep quality.

RESULTS

Mean body mass index (BMI) of the overweight/obese and control groups were 30.5±0.5 and 18.7±0.2, respectively. The frequency of RLS was higher in the obese group (21.7%) than the overweight (3.4%) and control (1.5%) (p<0.001) groups. The frequency of a poor PSQI score was significantly higher (p<0.001) in the obese group (37.3%) than the control group (24.2%). The obese with RLS group also had poorer sleep quality scores than the non-RLS obese group. Many symptoms of sleep disruption were more common in obese patients with RLS and RLS was independently correlated with a high PSQI score [odds ratio (OR): 2.25, confidence interval (Cl): 0.96-5.28, p<0.001)] and an increased BMI z-score (OR: 8.87, Cl: 2.04-38.61, p<0.001).

CONCLUSION

RLS is common in obese children and may be associated with altered sleep quality. Obese children with RLS need to be assessed since they may need support to improve their sleep quality.