Prevalence and clinical characteristics of sleep disorders in chronic obstructive pulmonary disease: A systematic review and meta-analysis

BACKGROUND

Sleep disorders, including obstructive sleep apnea (OSA), restless leg syndrome (RLS) and insomnia, are present in chronic obstructive pulmonary disease (COPD) with varied prevalence. The aim of this systematic review and meta-analysis was to investigate prevalence of OSA, RLS and insomnia in patients with COPD and summarize their clinical characteristics.

METHODS

We searched PubMed, Web of Science and Scopus for eligible articles reporting the prevalence of OSA, RLS, and insomnia in COPD patients. The Newcastle‒Ottawa scale was applied for quality assessment. Odds ratios or mean differences with 95 % confidence intervals (CIs) were applied for the overall prevalence calculation and clinical characteristics assessment. Sensitivity analysis, subgroup analysis and meta-regression were conducted to evaluate the heterogeneity of the results.

RESULTS

Sixty articles reporting the prevalence of sleep disorders in patients with COPD were included, and the prevalence of OSA, RLS, and insomnia reached 29.1 %(95%CI 27.2%-30.9 %), 21.6 %(95%CI 11.8%-33.3 %) and 29.5 %(95%CI 16.9%-44.0 %), respectively. COPD patients with OSA were characterized by male sex (OR 1.631 95 % CI: 1.231-2.161), obesity(kg/m2) (MD 4.435, 95 % CI 3.218-5.652), higher Epworth Sleepiness Scale (MD: 3.741, 95 % CI: 0.655-6.828, p = 0.018), better pulmonary function (MD 5.66, 95 % CI 3.546-7.774) and higher risks of hypertension (OR 1.933 95 % CI 1.382-2.70) and diabetes (OR 1.898 95 % CI 1.264-2.849). COPD patients with RLS were associated with a higher Epworth sleepiness scale (ESS) score (MD 3.444, 95 % CI 1.880-5.008) and a longer COPD duration(year) (MD: 3.656, 95 % CI: 2.209-5.103). COPD patients with insomnia were characterized by female sex(OR 0.556, 95%CI 0.545,0.567, p < 0.001).

CONCLUSION

Our study suggests that OSA, RLS and insomnia are common in COPD patients with specific clinical characteristics. Further studies are needed to explore the interactions between COPD and sleep disorders.

Restless legs syndrome affects sleep in de novo Parkinson's disease patients

Restless legs syndrome (RLS) is common in Parkinson's disease (PD) patients and can affect the motor symptoms and non-motor symptoms (NMSs) of PD patients. The aim of this study was to identify the clinical factors affected by RLS in patients with PD. We included 369 de novo PD patients. RLS was assessed via face-to-face interviews and the motor symptoms and NMSs of the patients were assessed using relevant scales. RLS frequency in the patients was 12.2% (45/369). PD patients with RLS (PD-RLS) exhibited a greater global Pittsburgh Sleep Quality Index (PSQI) score than those without RLS (PD-No RLS). PD-RLS exhibited significantly greater scores in the daytime dysfunction and sleep disturbances components of the PSQI than PD-No RLS. PD-RLS exhibited a significantly greater score in the cardiovascular, sleep/fatigue, and attention/memory subdomain of the Non-Motor Symptoms Scale than PD-No RLS. The International RLS Study Group rating scale score was significantly related to PSQI components scores in the sleep disturbances, sleep latency, habitual sleep efficiency, and subjective sleep quality. RLS frequency in de novo PD patients is higher than that in the general population, and the main NMS affected by RLS in these patients is sleep disturbances. Therefore, it is necessary to manage RLS in PD patients with sleep disturbances.

Restless legs syndrome in multiple sclerosis patients: Prevalence, impact, and association with disease-modifying therapies in a Saudi Arabian pilot study

BACKGROUND

Restless legs syndrome (RLS) emerges as a notable sleep disorder characterized by distressing sensations within the lower extremities. Its prevalence appears to be higher among patients afflicted with multiple sclerosis (MS) compared to the general population. Despite this observation, the understanding of the intricacies of RLS and its repercussions within the context of MS patients in Saudi Arabia remains limited.

METHODS

Employing a cross-sectional design, a comprehensive investigation was undertaken at King Fahad Armed Forces Hospital in Jeddah, Saudi Arabia, spanning from November 2021 to March 2022. A cohort of 66 individuals diagnosed with MS was recruited and subjected to an assessment for RLS employing the revised diagnostic criteria outlined by the International Restless Legs Syndrome Study Group (IRLSSG). Furthermore, the Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, and Sleepiness Scale were employed to gage the extent of RLS's impact on sleep quality and daily functioning.

RESULTS

The prevalence of RLS amidst the MS cohort was determined to be 30.4%. An observable association was discerned between RLS presence and higher scores on the Expanded Disability Status Scale (p < 0.001), along with diminished sleep quality scores (p < 0.001) and elevated fatigue scores based on IRLSSG criteria (p < 0.001). Within the studied MS cases, 98.5 % exhibited the relapsing-remitting subtype. Further investigation demonstrated that patients treated with Fingolimod or Ocrevus presented normal IRLSSG scores, whereas those undergoing Rituximab treatment manifested an even distribution between normal and moderate scores. Correspondingly, patients receiving interferons showcased 72.2 % with normal scores and 27.8 % with mild scores. Notably, a statistically significant variance in IRLSSG scores was observed when contrasting Fingolimod and Aubagio treatments (P < 0.001).

CONCLUSION

The presence of RLS as a comorbidity in MS patients within the Saudi Arabian context emerges as a significant finding, exerting a discernible detrimental influence on both disability status and sleep quality. This study underscores the need for further investigations aimed at unraveling the intricate pathophysiological underpinnings, identification of risk factors, and exploration of therapeutic modalities for RLS in this population. Furthermore, additional research endeavors are warranted to elucidate the diverse impact of various disease-modifying therapies on clinical outcomes.

Restless Legs Syndrome and fatigue in multiple sclerosis: A cross-sectional clinical study

BACKGROUND

Restless Legs Syndrome is a sleep-related sensorimotor disorder with a higher prevalence in Multiple Sclerosis (MS) patients than in the general population. Our aim was to determine the prevalence of RLS in a group of relapsing-remittent multiple sclerosis (RRMS) patients, and to investigate whether RLS is associated with MS-related disability, sleep quality, mood disorders and fatigue.

METHODS

In this retrospective, mono-centric, observational study, 92 RRMS patients were recruited (median age 46.5 years, 68.5% female patients). Data on MS clinical and radiological variables were collected. Patients underwent a subjective evaluation with standardized questionnaires on sleep fatigue and mood, which were evaluated by an expert neurologists specialized in sleep disorders about the occurrence of RLS.

RESULTS

Prevalence of RLS in our sample was of 47.8%. Patients with RLS had a significantly higher rate of worse sleep quality and fatigue, compared to non RLS subjects (respectively 56.8% vs. 35.4%, p=0.04 and 54.4% vs 22.7%, p=0.002). Univariate analysis showed that RLS was significantly more frequent in fatigued patients (66.7% vs 38.5% RLS- patients, p=0.009). Multivariate analysis showed that fatigue correlated with MS-related disability (OR 1.556, p=0.011), poor sleep quality (OR 1.192, p 0.036), and mood disorders (OR 1.096, p 0.046). RLS appears to independently increase the risk of fatigue of 50%, without reaching clear statistical significance (OR 1.572, p 0,0079).

CONCLUSION

Our study confirms the high prevalence of RLS in patients with multiple sclerosis and highlights the potential impact of RLS on fatigue and its strict interaction with sleep quality.

The Relationship between Serum Selenium Levels and Restless Leg Syndrome in Chronic Kidney Disease Patients

Background and Objectives: Chronic kidney disease (CKD) is a global public health issue with rising incidence linked to substantial morbidity and mortality. Selenium, an antioxidant trace element, has been linked to low serum levels in end-stage renal disease. Restless Leg Syndrome (RLS), a sleep disorder, is prevalent in CKD patients and significantly impacts their quality of life. The objective of this study was to examine the correlation between serum selenium levels and the prevalence of restless leg syndrome in individuals with chronic kidney disease. Materials and Methods: Forty-six CKD patients undergoing serum selenium level assessments between 1 January 2020 and 28 February 2022, at the Hitit University Faculty of Medicine Department of Nephrology Outpatient Clinic or Hemodialysis Unit, were included. Patients over 18 years of age with no history of hematological or oncological diseases or acute or chronic inflammatory conditions were included in the study groups. Patients taking selenium supplements were excluded. Demographic data, comorbidities, and laboratory values were collected, and RLS presence and severity were evaluated. Statistical analyses include descriptive statistics, correlation analysis, the Mann-Whitney U test, Student's t test, and Chi-square test. Results: Among the 46 patients, 16 (34.78%) had RLS symptoms. The patient group included 34.78% predialysis, 34.78% peritoneal dialysis, and 30.44% hemodialysis patients, with a median age of 47.98 years. There was no difference in age, gender, and Charlson comorbidity between patients with or without RLS (p = 0.881, p = 0.702, p = 0.650). RLS prevalence varied across CKD subgroups, with hemodialysis patients having a higher prevalence (p = 0.036). Clinical parameters such as blood urea nitrogen, creatinine, calcium, phosphorus, platelet counts, and parathyroid hormone levels exhibited significant differences between patients with and without RLS (p < 0.05). Serum selenium levels were not significantly different between patients with and without RLS (p = 0.327). Conclusions: With an increased comorbidity burden, CKD poses a significant healthcare challenge. When accompanied by RLS, this burden can be debilitating. The difference in CKD stages between groups has shed light on a critical determinant of RLS in this population, emphasizing the role of the chronic kidney disease stage. In our study, serum selenium levels were not associated with the presence and severity of RLS. However, prospective studies with larger numbers of participants are needed to draw a definitive conclusion.

Restless legs syndrome: From clinic to personalized medicine

Restless legs syndrome (RLS) is a common neurological sensorimotor disorder that impairs sleep, mood and quality of life. RLS is defined by an urge to move the legs at rest that increases in the evening and at night, and is frequently associated with metabolic and cardiovascular diseases. Symptoms frequency, age at RLS onset, severity, familial history and consequences of RLS vary widely between patients. A genetic susceptibility, iron deficiency, dopamine deregulation, and possible hypo-adenosinergic state may play a role in the pathophysiology of RLS. Polysomnographic recordings found often periodic leg movements during sleep and wakefulness in patients with RLS. RLS can be classified as primary or comorbid with major diseases: iron deficiency, renal, neurological, rheumatological and lung diseases. First-line treatments are low-dose dopamine agonists, and alpha-2-delta ligands depending on the clinical context, and second/third line opiates for pharmacoresistant forms of RLS. Augmentation syndrome is a serious complication of dopamine agonists and should be prevented by using the recommended low dose. Despite an increase in knowledge, RLS is still underdiagnosed, poorly recognized, resulting in substantial individual health burden and socioeconomic coast, and education is urgently needed to increase awareness of this disabling disorder.

Incident mental health episodes after initiation of gabapentinoids vs. dopamine agonists for early-onset idiopathic restless legs syndrome

Limited long-term safety information exists for gabapentinoid treatment of idiopathic restless legs syndrome (RLS). We estimated incident mental health-related emergency department visits and hospitalizations with a primary mental health diagnosis (primary outcome) among early-onset idiopathic RLS patients following first-line treatment initiation and examined outcome risk with gabapentinoids compared with dopamine agonists (DAs). A retrospective cohort study was conducted using administrative claims data from 2012 to 2019. Adults with early-onset (18-44 years) idiopathic RLS initiating either gabapentinoids or DAs within 60 days of new diagnosis were followed up to two years. Incidence rates were calculated and a log-binomial regression model with propensity score weighting estimated relative risk of the outcome and of substance use disorders (SUDs) as a secondary analysis with gabapentinoids. Among a cohort of 6,672 patients, 4,986 (74.7%) initiated DAs and 1,686 (25.3%) gabapentinoids. Incidence of the primary outcome (49.8 [95% CI 40.8-69.3] per 1,000 person-years) and SUDs (49.5 [95% CI 40.6-59.9] per 1,000 person-years) were higher in the gabapentinoid group compared with the DA group. A statistically significant risk of mental health diagnoses with gabapentinoids was not detected, but SUD risk was significant after covariate adjustment. High-risk mental health comorbidities (i.e., SUDs) should be considered when initiating RLS treatments.

Restless legs syndrome

BACKGROUND

Restless legs syndrome (RLS) is a common sensorimotor disorder causing significant distress and is commonly seen in the primary care setting.

OBJECTIVE

This article outlines the epidemiology, pathophysiology, diagnosis and management of RLS, with a focus on the primary care setting.

DISCUSSION

RLS is a clinical diagnosis, although mimics exist. Brain iron deficiency, dopaminergic dysfunction and genetics underpin the poorly understood pathophysiology of this common condition. After repleting iron stores, reviewing any exacerbating medications and attending to non-pharmacological management options, there are pharmacological options that prove to be effective, although with class-specific effects that need to be considered.

Restless legs syndrome in chronic renal failure patients on dialysis

Background

Restless legs syndrome (RLS) occurs in patients with chronic renal failure (CRF).

Objectives

To determine the prevalence and morbidity of RLS in CRF patients on dialysis.

Methods

This cross-sectional questionnaire-based study included 100 dialysis patients (50 on haemodialysis [HD]; 50 on peritoneal dialysis [PD]). A focused lower limb examination was done. Patients were classified with RLS when reporting uncomfortable feelings in their legs that improved with movement and worsened when resting and at night.

Results

Gender distribution was equal. The median age was 43 (19-67) years. Six patients (HD and PD n=3 each) had international criteria-confirmed RLS. Twenty-four patients reported symptoms suggestive of RLS. Fourteen and 16 patients with RLS symptoms were on HD and PD, respectively. Sleep disturbances occurred in 43.3% (n=13) of patients with RLS symptoms, compared to 20.0% (n=20) of the large cohort. Sleep disturbances, peripheral sensory loss, chronic disease-related anaemia, increased urea and decreased albumin levels were more common among patients with RLS symptoms.

Conclusion

RLS symptoms occurred in 30.0% of the entire cohort, although only 6.0% met the international criteria. The type of dialysis had no impact on the incidence of symptoms. Identifying RLS in patients with CRF on dialysis will allow for early intervention.

Insomnia and workplace productivity loss among young working adults: a prospective observational study of clinical sleep disorders in a community cohort

OBJECTIVE

To examine associations between three clinically significant sleep disorders (chronic insomnia, obstructive sleep apnoea, restless legs syndrome) and workplace productivity losses among young Australian adults.

DESIGN, SETTING

Prospective, observational study; 22-year follow-up of participants in the longitudinal birth cohort Raine Study (Perth, Western Australia).

PARTICIPANTS

Currently employed 22-year-old Raine Study participants who underwent in-laboratory sleep disorder screening for moderate to severe obstructive sleep apnoea (apnoea-hypopnea index of more than fifteen events/hour or obstructive sleep apnoea syndrome) and were assessed for insomnia and restless legs syndrome using validated measures.

MAIN OUTCOME MEASURES

Total workplace productivity loss over twelve months, assessed with the World Health Organization Health and Work Performance Questionnaire.

RESULTS

Of 1235 contactable 22-year-old Raine Study cohort members, 554 people (44.9%; 294 women [53%]) underwent overnight polysomnography, completed the baseline sleep questionnaire, and completed at least three quarterly workplace productivity assessments. One or more clinically significant sleep disorders were identified in 120 participants (21.7%); 90 participants had insomnia (17%), thirty clinically significant obstructive sleep apnoea (5.4%), and two restless legs syndrome (0.4%). Seventeen people (14% of those with sleep disorders) had previously been diagnosed with a sleep disturbance by a health professional, including fourteen with insomnia. Median total workplace productivity loss was greater for participants with sleep disorders (164 hours/year; interquartile range [IQR], 0-411 hours/year) than for those without sleep disorders (30 hours/year; IQR, 0-202 hours/year); total workplace productivity loss was 40% greater for participants with sleep disorders (adjusted incidence rate ratio, 1.40; bias-corrected and accelerated 95% confidence interval, 1.10-1.76). The estimated population total productivity loss (weighted for disorder prevalence) was 28 644 hours per 1000 young workers per year, primarily attributable to insomnia (28 730 hours/1000 workers/year).

CONCLUSION

Insomnia is a risk factor for workplace productivity loss in young workers. Tailored interventions are needed to identify and manage sleep disorders, particularly as most of the sleep disorders detected in the Raine Study had not previously been diagnosed.

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.

Dopamine agonists and risk of lung cancer in patients with restless legs syndrome

PURPOSE

To examine the association between long-term use of dopamine agonists (DAs) and the risk of lung cancer in patients with restless legs syndrome (RLS).

METHODS

We conducted a retrospective cohort study using Optum Clinformatics® database. We included adults ≥40 years diagnosed with RLS during the study period (1/2006-12/2016). Follow-up started with the first RLS diagnosis and ended on the earliest of: incident diagnosis of lung cancer, end of enrollment in the database or end of the study period. The exposure of interest was cumulative duration of DAs use, measured in a time-varying manner. We constructed a multivariable Cox regression model to estimate HRs and 95% CIs for the association between lung cancer and cumulative durations of DA use, adjusting for potential confounding variables.

RESULTS

We identified 295 042 patients with a diagnosis of RLS. The mean age of the cohort was 62.9; 66.6% were women and 82.3% were white. The prevalence of any DA exposure was 40.3%. Compared to the reference group (no use and ≤1 year), the crude HRs for lung cancer were 1.16 (95% CI 0.99-1.36) and 1.14 (95% CI 0.86-1.51) for 1-3 years and >3 years of cumulative DA use, respectively. The adjusted HR for lung cancer was 1.05 (95% CI 0.88-1.25) for 1-3 years and 1.02 (95% CI 0.76-1.37) for >3 years of cumulative DA use, respectively.

CONCLUSIONS

At typical doses for the clinical management of RLS, long-term DA use was not associated with risk of lung cancer.

Neurologic Disorders in Women and Sleep

Sleep disorders in women remain underrecognized and underdiagnosed mainly because of gender bias in researching and characterizing sleep disorders in women. Symptoms of common sleep disorders are frequently missed in the general female population and are expected to be further overlooked because of overlapping symptoms in women with neurologic disorders. Given the bidirectional relationship with sleep and neurologic disorders, it remains critical to be aware of the presentation and impact of sleep disorders in this patient population. This article reviews available data on sleep disorders in women with neurologic disorders and discusses their distinctive features.

Prevalence and severity of restless leg syndrome in patients with spinal cord injuries

OBJECTIVE

To determine the prevalence of restless leg syndrome in patients with spinal cord injury using a consensus criterion.

METHODS

The cross-sectional study was conducted from November 29, 2018, to February 28, 2021 at the departments of Neurology and Orthopaedic Surgery, King Edward Medical University, Mayo Hospital, Lahore, Pakistan, and comprised patients of either gender aged 18-80 years having spinal cord injuries. All the patients were interviewed using a 10-item questionnaire, and were assessed using the five-point consensus criteria of the International Restless Leg Syndrome Study Group. Data was analysed using SPSS 20.

RESULTS

Of the 253 patients, 128(50.6%) were males and 125(49.4%) were females. The overall mean age was 38.6±14.2 years. Restless leg syndrome was present in 116(45.8%) patients, and 64(55.2%) of them were males (p>0.05). The mean duration of the symptoms was 18.9±16.9 months. Causes of spinal cord injury included metastasis 28(11.1%) multiple sclerosis 32(12.6%), neuromyelitis optica spectrum disorders 68(26.9%), tuberculous spondylitis 85(33.6%), trauma 24(9.5%) and viral myelitis 16(6.3%).

CONCLUSIONS

Restless leg syndrome was prevalent in less than half the patients having spinal cord injury. It was more prevalent in males compared to females, but the difference was not significant.

The frequency of non-motor symptoms in SCA3 and their association with disease severity and lifestyle factors

BACKGROUND

Non-motor symptoms (NMS) are a substantial burden for patients with SCA3. There are limited data on their frequency, and their relation with disease severity and activities of daily living is not clear. In addition, lifestyle may either influence or be affected by the occurrence of NMS.

OBJECTIVE

To characterize NMS in SCA3 and investigate possible associations with disease severity and lifestyle factors.

METHODS

In a prospective cohort study, we performed a cross-sectional analysis of NMS in 227 SCA3 patients, 42 pre-ataxic mutation carriers, and 112 controls and tested for associations with SARA score, activities of daily living, and the lifestyle factors alcohol consumption, smoking and physical activity.

RESULTS

Sleep disturbance, restless legs syndrome, mild cognitive impairment, depression, bladder dysfunction and pallhypesthesia were frequent among SCA3 patients, while mainly absent in pre-ataxic mutation carriers. Except for restless legs syndrome, NMS correlated significantly with disease severity and activities of daily living. Alcohol abstinence was associated with bladder dysfunction. Patients with higher physical activity showed less cognitive impairment and fewer depressive symptoms, but these differences were not significant.

CONCLUSION

This study revealed a clear association between disease severity and NMS, likely driven by the progression of the widespread neurodegenerative process. Associations between lifestyle and NMS can probably be attributed to the influence of NMS on lifestyle.

Sleep-related motor disorders

Sleep-related motor disorders include non-rapid-eye movement (NREM) sleep parasomnias, rapid-eye movement (REM), sleep parasomnias including REM sleep behavior disorder (RBD), isolated motor phenomena in sleep, and periodic limb movement disorder. Restless legs syndrome (RLS) occurs while awake but is closely related to sleep and has a circadian pattern. The pontine sublaterodorsal tegmental nucleus has an important role in aligning motor control with sleep states, and dysfunction in this region can explain motor activities including cataplexy and loss of REM atonia seen in REM sleep behavior disorder. This chapter begins with a review of motor control in sleep. The rest of the chapter summarizes the clinical presentation, epidemiology, differential and treatment of NREM, REM, and isolated sleep-related motor disorders as well as restless legs syndrome.

[Restless sleep disorder a new entity to considered in children]

Restless sleep disorder (RSD) is a condition recently described by a group of sleep experts who developed diagnostic and polysomnographic criteria after conducting a comprehensive review of the available literature where poor sleep or restless sleep is a symptom alone or that accompanies other disorders. This group defined RSD as a condition characterized by parental complaints of frequent jerking movements during sleep, position changes, and sleep disruption that cause significant impairment during the day. Diagnostic criteria include the presence of symptoms for at least 3 months, 3 times a week, and at least 5 movements per hour on polysomnography. Changes in behavior during the day, such as drowsiness, irritability, and hyperactivity that are not explained by a medical, pharmacological, or behavioral condition, should be considered. Its estimated prevalence is 7.7% of children referred for sleep problems. Children often have ferritin levels below 50 µg/l, a point in common with restless legs syndrome. Treatment consists of iron supplements, which have shown benefits in these children. To establish the diagnosis, secondary symptoms of medical origin or other sleep disorders such as restless legs syndrome or periodic limb movement disorder must be ruled out. The objective of this report is to review the current recommendations on this entity, describe the clinical, pathophysiological, and polysomnographic keys, in order to highlight the need to publicize this condition and expand studies in age groups other than those already defined and to generate treatment guidelines.

LAG3/CD4 Genes Variants and the Risk for Restless Legs Syndrome

According to several studies, inflammatory factors could be related to the pathogenesis of idiopathic restless legs syndrome (RLS). In addition, RLS and Parkinson's disease (PD) have shown a possible relationship, and recent studies have shown an association between CD4 rs1922452 and CD4 rs951818 single nucleotide variants (SNVs) and the risk for PD. For these reasons, we investigated the possible association between common variants in the LAG3/CD4 genes (which encoded proteins involved in inflammatory and autoimmune responses) and the risk for RLS in a Caucasian Spanish population. We assessed the frequencies of CD4 rs1922452, CD4 rs951818, and LAG3 rs870849 genotypes and allelic variants in 285 patients with idiopathic RLS and 350 healthy controls using a specific TaqMan-based qPCR assay. We also analyzed the possible influence of the genotypes' frequencies on several variables, including age at onset of RLS, gender, family history of RLS, and response to drugs commonly used in the treatment of RLS. We found a lack of association between the frequencies of genotypes and allelic variants of the 3 SNVs studied and the risk of RLS, and a weak though significant association between the CD4 rs1922452 GG genotype and an older age at onset of RLS. With the exception of this association, our findings suggest that common SNVs in the CD4/LAG3 genes are not associated with the risk of developing idiopathic RLS in Caucasian Spanish people.

Sleep microstructure and clinical characteristics of patients with restless legs syndrome

STUDY OBJECTIVES

Restless legs syndrome (RLS) is a sleep-related movement disorder, often accompanied by sleep disruption. Obstructive sleep apnea (OSA) has a controversial prevalence among patients with RLS. We evaluated the clinical and sleep features of patients who attended our sleep clinic considering RLS and OSA.

METHODS

In this cross-sectional study, we obtained health records of 1,497 patients during 2015-2019 who underwent polysomnography (PSG). Baseline characteristics, sleep-related and RLS questionnaires, and sleep microstructure were assessed. Descriptive and analytical assessments were performed. RLS was assessed according to the International Restless Legs Syndrome Study Group criteria.

RESULTS

RLS was found in 19.4% of patients, with more prevalence among women (26.9% vs 16.4%). RLS affected 19.1% of patients with OSA. Patients with RLS were significantly older with higher insomnia and depression and worse PSG results. As the respiratory disturbance index increased, the odds of RLS slightly decreased (adjusted odds ratio [95% confidence interval]: 0.80 [0.67-0.94]). The odds of OSA (respiratory disturbance index ≥ 5) was not affected by RLS. OSA in patients with RLS was significantly associated with a higher limb movement index. RLS in patients with OSA was significantly associated with higher insomnia, depression, and limb movement index (men and women), higher wake after sleep onset and percentage of N1 sleep (men), and lower sleep efficiency (men).

CONCLUSIONS

Patients with RLS had worse PSG results, higher insomnia, and depression. Although men with OSA+/RLS+ had worsened PSG results, PSG parameters in women with OSA+/RLS+ did not differ from the OSA+/RLS- group. Patients with either OSA or RLS should be evaluated for possible comorbidities, including insomnia and depression. Notably, sex-specific characteristics need more consideration in sleep clinics.

CITATION

Amirifard H, Jameie M, Akbarpour S, et al. Sleep microstructure and clinical characteristics of patients with restless legs syndrome. J Clin Sleep Med. 2022;18(11):2653-2661.

Screening and management of sleep disorders in patients with fibromyalgia syndrome: a French multicentred, prospective, observational study protocol (FIBOBS)

INTRODUCTION

Sleep disorders are still often underestimated in patient care management even though they are present in the criteria of the American College of Rheumatology for the diagnosis of fibromyalgia syndrome (FMS). The objective of this study will be to assess the current situation of sleep disorders in patients with FMS in France and to estimate its prevalence.

METHODS AND ANALYSIS

The FIBOBS study is a multicentred, prospective, observational trial performed by 46 specialised chronic pain structures in France. Patients with FMS visiting for a first consultation or follow-up (if they have already been followed up for less than a year with a pain management service) will be included after giving their informed consent. Data will be collected through the physician questionnaire filled during the inclusion visit. Patient self-questionnaires will be completed from home. The primary outcome of the study will be to estimate the prevalence of sleep disorders classified into three categories: (a) poor sleep quality in general, (b) sleep apnoea syndrome and (c) restless legs syndrome, using self-administered questionnaires.

ETHICS AND DISSEMINATION

This protocol is approved by the ethics committee Comité de Protection des Personnes 'Ile de France II' in accordance with French regulations. The results will be disseminated through peer-reviewed journals and conferences.

TRIAL REGISTRATION NUMBER

NCT04775368.

Restless Leg Syndrome in Hemodialysis Patients: A Narrative Review

BACKGROUND

Restless legs syndrome (RLS) is a clinical entity characterized by sensory-motor manifestations commonly observed in end-stage renal illness. Evidence suggests that RLS is a multifactorial phenomenon that can be influenced by many critical factors, including genetic predisposition, dietary patterns, and deficiency in some vitamins. Iron metabolism disorders and metabolic derangements have been generally accepted as predisposing elements in RLS. Furthermore, both pharmacological and neuroimaging studies demonstrated dopamine deficiency and dopamine receptors decrease in basal ganglia during RLS.

REVIEW SUMMARY

A literature search was done in three databases (PubMed, Google Scholar, and Cochrane) to identify the pertinent articles discussing the epidemiology, pathogenesis, and management of RLS in hemodialysis patients. RLS can affect the morbidity and mortality of patients treated with dialysis. It also has significant impacts on the quality of life since it can lead to insomnia, increased fatigue, mental health troubles, and other movement problems. Appropriate measures should be considered in this particular population so to prevent and treat RLS. Many drugs and other nonpharmacological methods have been investigated to attenuate the disease's severity. No treatment, however, could offer long-term effects.

CONCLUSION

Further efforts are still required to improve the understanding of RLS pathogenic trends to find more specific and efficient therapies. A wide range of treatment options is available. However, it can be individualized according to the patients' several factors.

Association between Self-Perceived Periodic Limb Movement during Sleep and Excessive Daytime Sleepiness Depend on Restless Leg Symptoms in Korean Adolescents

Although periodic limb movement during sleep (PLMS) and restless legs syndrome (RLS) are common in children and adolescents, they are relatively overlooked as a target of treatment. PLMS has been evaluated as having a lower clinical significance than RLS. This study examined the relationship of socio-behavioral factors of PLMS in Korean adolescents and checked whether PLMS is associated with excessive daytime sleepiness (EDS), depending on whether restless legs symptoms accompany it. In a cross-sectional study, 25,789 adolescents between 12 and 18 years of age (15.76 ± 1.73 years; female 51.49%) were evaluated using an online survey. Various self-report questionnaires were used to assess PLMS and RLS symptoms, EDS, sleep habits, and various socio-behavioral factors. The prevalence of self-perceived PLMS and restless legs symptoms were 903 (3.50%) and 1311 (5.08%), respectively. Of the 1311 participants, 399 had self-perceived PLMS. The odds ratios (ORs) for self-perceived PLMS in participants with restless legs symptoms were: males (OR = 1.528; 95% CI: 1.145–2.040), usually/always experienced apnea apnea (OR, 3.006; 95% CI, 1.954–4.624), increased proneness to Internet addiction (OR = 1.013; 95% CI: 1.001–1.025), sometimes/often consuming coffee (OR = 1.312; 95% CI: 1.015–1.695), EDS (OR = 0.826; 95% CI: 0.488–1.398), and perceived insufficient sleep (OR = 1.143; 95% CI: 0.835–1.565). The male gender, witness apnea, consuming coffee, and being prone to Internet addiction were identified as factors significantly associated with self-perceived PLMS in participants with restless legs symptoms. However, EDS and insufficient sleep were associated with self-perceived PLMS in the absence of restless legs symptoms.

[Exposure to dopamine agonists for treatment of restless legs syndrome led to suffering of ICD]

Impulse control disorders (ICD) may occur with the use of dopamine agonists (DAA), a class of medication usually prescribed for Parkinson's disease but also restless legs syndrome (RLS) and prolactinoma.  We describe a case that illustrates, in consistence with international literature, how exposure to DAA for treatment of RLS can lead to suffering of ICD with devastating consequences. Discontinuation of the dopaminergic agent (and potentially switching to another medication of a different class) can be an effective management strategy, and we suggest that it is very important to improve the knowledge of this phenomenon among clinicians and prompt active screening for ICD in this population.