Prospective study of restless legs syndrome and mortality among men

Sleep disorders and mortality: A prospective study in the Canadian longitudinal study on aging

BACKGROUND AND OBJECTIVES

Sleep disorders are commonly linked to various health conditions, although it remains unclear to what degree they are linked with overall mortality. We compared mortality in different self-reported sleep disorders in a large population-based prospective study.

METHODS

In this case-control study within the CLSA cohort, participants completed a questionnaire at baseline (2011-2015) measuring overall sleep satisfaction, daily sleep duration, sleep-onset and sleep-maintenance insomnia, daytime somnolence, REM sleep behavior disorder (RBD), restless leg syndrome (RLS), and obstructive sleep apnea (OSA). The vital status of participants was assessed in July 2019. Baseline sleep problems of participants who died (cases) were compared to those who survived (controls). For each case, five age/sex-matched controls were selected. Binary logistic regression was used to estimate the association between sleep symptoms and mortality, adjusting for age, sex, marital status, province, education, alcohol consumption, smoking, caffeine, and body mass index. In a complementary model, anxiety and depression were also added.

RESULTS

Among 30,097 participants at baseline, 974 deaths were reported in 2019 (60.7 % male, age = 72.3 ± 9.4 years). In the initial analysis, mortality cases reported more baseline sleep-maintenance insomnia (12.1 % vs. 8.0 %, Adjusted OR[95%CI] = 1.62[1.15,2.29]), daytime somnolence (2.4 % vs. 1.1 %, AOR = 2.70[1.34,5.44]), and higher possible RLS (16.4 % vs. 12.4 %, AOR = 1.50[1.09,2.05]). They were also more likely to screen positive for possible OSA (33.8 % vs. 24.2 %, AOR = 1.32[1.07,1.64]); however, this effect was not related to core apnea symptoms. Sleep durations exceeding 10 h/day were also associated with increased mortality (3.4 % vs. 1.9 %, AOR = 1.83[1.04,3.24]). Other sleep symptoms/disorders, such as sleep-onset insomnia (7.3 % vs. 4.3 %, AOR = 1.54 [1.00,2.37]), possible RBD (5.3 % vs. 5.1 %, AOR = 1.02[0.62,1.69]), and overall sleep dissatisfaction (26.5 % vs. 22.6 %, AOR = 1.14[0.93,1.41]) were not different among these groups. After adding anxiety and depression to the adjustment model, all differences attenuated to become statistically non-significant, except for daytime somnolence disorder. When stratified by sex, the association between sleep disorders and mortality was only observed in women, with men showing no association.

DISCUSSION

We confirm a relationship between numerous sleep disorders and mortality. This effect is most evident in women, and appears to be strongly related to co-existing anxiety and depression.

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.

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.

A longitudinal study of restless legs symptoms among patients with depression

BACKGROUND

The aim of this study was to analyse the relationship between depressive symptoms and clinical depression and restless legs symptoms in a longitudinal primary care setting.

METHODS

The prevalence of restless legs symptoms at baseline and after a six-year follow-up was studied in 474 patients with depressive symptoms and 333 population-based control subjects without depressive symptoms. Depressive symptoms at the baseline and after the six-year follow-up were evaluated with the Beck Depression Inventory (BDI) Second Edition. A psychiatric diagnosis was confirmed with a diagnostic interview (M.I.N.I.). Statistical comparisons between groups were made using analysis of variance (ANOVA) for continuous variables and a chi-square test or logistic models for categorical variables. Repeated measures were analysed using generalizing estimating equations (GEE) models.

RESULTS

At baseline the prevalence of restless legs symptoms was 24.3% in control subjects, 43.8% in the patients with depressive symptoms without a depression diagnosis, and 49.3% in clinically depressed patients. During the follow-up up the prevalence of restless legs symptoms declined significantly (p = 0.003). In addition to baseline restless legs symptoms, the prognostic factors for restless legs symptoms among patients with clinical depression were age and BDI score. In the control subjects, moderate and high leisure time physical activity was inversely associated with restless legs symptoms at the follow-up.

CONCLUSIONS

A higher level of baseline depressive symptoms was a risk factor for restless legs symptoms in patients with clinical depression. In the prevention and treatment of restless legs symptoms among the patients with depression, the priority is the effective treatment of depression.

Genetic evidence for a potential causal relationship between insomnia symptoms and suicidal behavior: a Mendelian randomization study

Insomnia and restless leg syndrome (RLS) are associated with increased risk for suicidal behavior (SB), which is often comorbid with mood or thought disorders; however, it is unclear whether these relationships are causal. We performed a two-sample Mendelian randomization study using summary-level genetic associations with insomnia symptoms and RLS against the outcomes of risk of major depressive disorder (MDD), bipolar disorder (BP), schizophrenia (SCZ), and SB. The inverse-variance weighted method was used in the main analysis. We performed replication and sensitivity analyses to examine the robustness of the results. We identified outcome cohorts for MDD (n = 170,756 cases/329,443 controls), BP (n = 20,352/31,358), SCZ (n = 69,369/236,642), SB-Cohort-2019 (n = 6569/14,996 all with MDD, BP or SCZ; and SB within individual disease categories), and SB-Cohort-2020 (n = 29,782/519,961). Genetically proxied liability to insomnia symptoms significantly associated with increased risk of MDD (odds ratio (OR) = 1.23, 95% confidence interval (CI) = 1.2-1.26, P = 1.37 × 10-61), BP (OR = 1.15, 95% CI = 1.07-1.23, P = 5.11 × 10-5), SB-Cohort-2019 (OR = 1.17, 95% CI = 1.07-1.27, P = 2.30 × 10-4), SB-Cohort-2019 in depressed patients (OR = 1.34, 95% CI = 1.16-1.54, P = 5.97 × 10-5), and SB-Cohort-2020 (OR = 1.24, 95% CI = 1.18-1.3, P = 1.47 × 10-18). Genetically proxied liability to RLS did not significantly influence the risk of any of the outcomes (all corrected P > 0.05). Results were replicated for insomnia with MDD and SB in Mass General Brigham Biobank and were consistent in multiple lines of sensitivity analyses. In conclusion, human genetic evidence supports for the first time a potentially independent and causal effect of insomnia on SB and encourages further clinical investigation of treatment of insomnia for prevention or treatment of SB.

High National Rates of High-Dose Dopamine Agonist Prescribing for RLS

Study Objectives

Long-term dopamine agonist (DA) use in restless legs syndrome (RLS) is associated with augmentation, a dose-related symptom worsening leading to further dose escalation to manage RLS. This study investigated rates and factors of high-dose DA prescribing in US RLS patients.

Methods

This retrospective analysis examined data from a US longitudinal prescriptions database (October 2017–September 2018). Patients diagnosed with RLS (ICD-10 G255.81) without Parkinson’s disease who were prescribed ropinirole, pramipexole, and/or rotigotine were included. Daily DA dosage was categorized: LOW/MID (US Food and Drug Administration [FDA]-approved/guideline or slightly above FDA-approved [pramipexole]); HIGH (101%–149%); VERY HIGH (>150%). Patient counts were converted to US national estimates. Logistic regression of patient counts evaluated factors associated with HIGH/VERY HIGH DA dosing.

Results

Of 670,404 RLS patients (131,289,331 therapy days), 58.8% were prescribed DA therapy. Overall, 19.1% of RLS patients were prescribed DAs above maximum FDA-approved/guideline daily doses—over half of these were >150% maximum recommended doses; 67.6% of HIGH/VERY HIGH-dose prescriptions were pramipexole (OR [95% CI] pramipexole vs ropinirole, 5.8 [5.7 to 6.0]). The highest 1% of DA prescriptions were ≥10× the FDA-recommended maximum daily dose. Rates of HIGH/VERY HIGH DA dosing increased with patient age. Twice as many neurologists (31.1%) prescribed HIGH/VERY HIGH doses vs other specialties (OR [95% CI], 2.1 [1.2 to 2.0]).

Conclusions

Approximately 20% of DA-treated RLS patients were prescribed doses above the approved and guideline daily maximum. Pramipexole, Neurology as specialty, and patient age were independently associated with HIGH/VERY HIGH DA dosing. Increased education is warranted regarding risks of high-dose DA exposure in RLS.

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.

Treating Restless Legs Syndrome Was Associated With Low Risk of Cardiovascular Disease: A Cohort Study With 3.4 Years of Follow-Up

Background Restless legs syndrome (RLS) is associated with higher cardiovascular disease (CVD) risk. However, it remains unknown whether treatment of RLS lowers the cardiovascular risk associated with RLS. Methods and Results All data were collected retrospectively, but subjects were prospectively followed forward in time to determine outcomes of interest. We used the Truven Health MarketScan Commercial Claims and Encounters database from January 1, 2006, through December 31, 2014. Participants were 169 393 individuals, which included 24 199 nonpregnant participants with an RLS diagnosis (16 694 receiving treatments for RLS and 7505 without treatment) during 2006 to 2008 and 145 194 age- and sex-matched participants without RLS. All participants were free of CVD before January 1, 2009 (analysis baseline). Incident CVD cases (myocardial infarction, angina, stroke, atrial fibrillation, and heart failure) were identified. We adjusted for potential confounders, such as presence of chronic conditions and medication use. We identified 16 574 incident CVD cases during 2009 to 2014. Relative to the non-RLS group, the adjusted hazard ratio (HR) for future CVD was 1.26 (95% CI, 1.20-1.32) (P<0.001) for the RLS with treatment group, and 1.53 (95% CI, 1.42-1.65) (P<0.001) for the RLS without treatment group. Significant lower CVD risk was observed for all different RLS treatments, including dopaminergics, anticonvulsants, benzodiazepines, and opiates (adjusted HRs range, 0.71-0.84; P<0.001 for all), except for ergot-dopamine use. Conclusions RLS was associated with higher future CVD risk. However, RLS was associated with statistically significantly less future cardiovascular risk in RLS patients with treatment than in those without treatment.

Effectiveness and safety of massage in the treatment of restless legs syndrome: A protocol for systematic review and meta analysis

BACKGROUND

Restless legs syndrome (RLS), known as a kind of neurological disease, is prevalent but easy to be ignored. Studies have demonstrated that massage therapy can effectively reduce the symptoms of patients with RLS and improve their quality of life. However, the efficacy of massage therapy for RLS is still controversial. Therefore, this protocol aims to evaluate the reliability of massage therapy in treating RLS in a thorough way.

METHODS

We will search relevant randomized controlled trials from Chinese Biomedical Literature Database, Chongqing VIP, CNKI, Wanfang, Web of Science, Cochrane Library, PubMed, and EMBASE, when publication status and language are not considered and the time limit ends with September 6, 2020. Two experienced researchers will use RevMan V.5.3 software to perform the selection of literature, data collection, data analysis and synthesis separately. Besides, the quality of trials involved in this study will be measured with the Cochrane bias risk assessment tool.

RESULTS

This protocol will be applied to carry out a systematic evaluation of the massage therapy purposed to treat RLS for its effectiveness and safety.

CONCLUSION

The review will provide a credible evidence suggesting whether massage therapy is a reliable intervention for RLS.

INPLASY REGISTRATION NUMBER

INPLASY202090038.

Bioinformatic analysis of proteomic data for iron, inflammation, and hypoxic pathways in restless legs syndrome

OBJECTIVE/BACKGROUND

We performed bioinformatic analysis of proteomic data to identify the biomarkers of restless legs syndrome (RLS) and provide insights into the putative pathomechanisms, including iron deficiency, inflammation, and hypoxic pathways.

PATIENTS/METHODS

Patients with drug-naïve idiopathic RLS were recruited at a university hospital from June 2017 to February 2018. Serum samples from patients with RLS (n = 7) and healthy sex- and age-matched controls (n = 6) were evaluated by proteomic analysis. For differentially expressed proteins (DEPs) in patients with RLS, compared to those in controls, the expression profiles and protein-protein interaction (PPI) network were characterized between dysregulated proteins and extracted proteins involved in iron deficiency, hypoxia, and inflammation responses using the String database (http://string-DB.org). The PPI network was visualized by Cytoscape ver. 3. 7. 1. Statistical analyses of the validation Western blot assays were performed using a Student's t-test.

RESULTS

Interactome network analysis revealed a relationship among the eight proteins, their associated genes, and 150, 47, and 11 proteins related to iron deficiency, inflammation, and hypoxic pathways, respectively. All DEPs were well associated with inflammation, and complement 3, complement C4A, alpha-2 HS glycoprotein, and alpha-2 macroglobulin precursor were found to be in hub positions of networks involved in PPIs including iron deficiency, hypoxia pathway, and inflammation. C3 and C4A were verified using western blotting.

CONCLUSIONS

We identified key molecules that represent the selected cellular pathways as protein biomarkers by PPI network analysis. Changes in inflammation can mediate or affect the pathomechanism of RLS and can thus act as systemic biomarkers.

Survival in Restless Legs Syndrome: An 11-Year Surveillance, Community-Based Population Study

<b><i>Background:</i></b> A growing body of evidence relates restless legs syndrome (RLS) to an increased risk of mortality attributable to both cerebrovascular and cardiovascular events. The aim was to investigate survival in patients with RLS. <b><i>Methods:</i></b> This was an observational, retrospective longitudinal study of a cohort of patients followed up for 11 years. RLS was diagnosed by a physician using the International RLS Study Group criteria. Mortality was analyzed using age-standardized mortality ratios (SMR: observed/expected deaths) and Cox regression analysis. <b><i>Results:</i></b> Vital status was studied in a cohort of 232 patients: 181 women (78%), 96 with RLS (41.4%) with a mean age at baseline of 49.8 ± 15.0 years and a mean RLS duration of 14.1 ± 1.9 years, and 136 non-RLS (58.6%) with a mean age of 51.3 ± 14.9 years. This RLS cohort was followed up for a period of 10.4 ± 2.0 years. As of September 2019, 17 (7.3%) patients died (6 with RLS, 6.3%), and the most frequent cause was oncological (66.7%). A total of 944 person-years of observations were available for survival analysis. RLS was not associated with increased mortality in adjusted Cox regression analysis (HR = 1.12, 95% CI: 0.40–3.15), and survival was similar to that expected for the general population (SMR = 0.61, 95% CI: 0.27–1.36). <b><i>Conclusions:</i></b> RLS seems not to be associated with increased mortality compared to the general population. Still, studies with prospective data collection with large samples are needed to study the long-term mortality risk factors in RLS cohorts.

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.

Blood pressure profile and endothelial function in restless legs syndrome

Restless legs syndrome (RLS) is frequently comorbid with hypertension and cardiovascular diseases; however this relationship and underlying mechanisms remain controversial. After clinical evaluation, 84 drug-free patients with primary RLS (53 women; mean age 55.1 ± 12.3 years) and 76 controls (47 women; mean age 52.2 ± 15.3 years) underwent 24-hour ambulatory blood pressure (BP) and polysomnographic monitoring, and peripheral arterial tonometry to assess endothelial function for 61 patients and 69 controls. Hypertension was diagnosed in 11.9% of patients with RLS based on office measurement, and in 46.4% on the 24 h recording, with nighttime hypertension, two times more frequent than daytime hypertension. Periodic limb movement during sleep (PLMS), markers of sleep fragmentation, and systolic and mean BP non-dipping profile were more frequent among patients. BP non-dipping status was associated with older age, later RLS onset and diagnosis, RLS severity and higher sleep fragmentation. The mean 24-hour, daytime and nighttime BP values, the frequency of hypertension and the endothelial function were comparable between groups. However, both systolic and diastolic BP trajectories over a 24-hour period differed between groups. In conclusion, patients with RLS exhibit a 24-hour BP deregulation with increased frequency of systolic non-dipping profiles that could worsen the risk for CVD morbidity and mortality.

Increased Risk for New-Onset Psychiatric Adverse Events in Patients With Newly Diagnosed Primary Restless Legs Syndrome Who Initiate Treatment With Dopamine Agonists: A Large-Scale Retrospective Claims Matched-Cohort Analysis

STUDY OBJECTIVES

Published literature documents increased risk for psychiatric adverse events (P-AEs) following dopamine agonist (DA) initiation for treatment of primary restless legs syndrome (RLS). We examined the association between DA initiation and subsequent new-onset P-AEs among patients with a new diagnosis of RLS who had no history of psychiatric disorder or DA use.

METHODS

Selected were adults (age 18 years or older) enrolled through United States employer-sponsored plans and Medicare Advantage from 7/1/2008-12/31/2014, with ≥ 2 years of claims data preceding their first RLS diagnosis ("preindex period"). Excluded were those with psychiatric diagnoses (International Classification of Diseases, Ninth Revision [ICD-9] 290-319) or DA use during the preindex period, and those with possible secondary RLS. Patients who initiated (DA+) versus did not initiate (DA-) DAs were matched 1:1 on age at index RLS diagnosis, sex, geographic region, and employment status, and preindex period comorbid illness burden and number of non-DA drug fills. Using a validated ICD-9-based severity-of-illness psychiatric disorder classification system, we compared likelihoods of new-onset P-AEs between matched pairs during parallel follow-up periods.

RESULTS

Identified were 889 matched pairs. Compared with their DA- counterparts, DA+ patients were nearly two times more likely to experience development of any P-AE (odds ratio [OR] 1.71, 95% confidence interval [CI] 1.31-2.24, P < .0001); and similarly more likely to experience the development of a severe (OR 1.68, 95% CI 1.03-2.86, P = .04), moderately severe (OR 1.63, 95% CI 1.17-2.29, P = .004), or mild (OR 1.72, 95% CI 1.12-2.65, P = .01) P-AE.

CONCLUSIONS

Compared to DA- matched control patients, patients in whom RLS was newly diagnosed and who initiated de novo DAs demonstrated significantly increased risk for subsequent development of P-AEs of any severity.

CITATION

Hankin C, Lee D, Garcia-Borreguero D, Wang Z. Increased risk for new-onset psychiatric adverse events in patients with newly diagnosed primary restless legs syndrome who initiate treatment with dopamine agonists: a large-scale retrospective claims matched-cohort analysis. J Clin Sleep Med. 2019;15(9): 1225-1232.

Association of Restless Legs Syndrome With Risk of Suicide and Self-harm

IMPORTANCE

Restless legs syndrome (RLS) is a common neurologic disorder that has been previously found to be associated with higher odds of suicidal ideation. In the context of the increasing suicide rate in the United States, the evidence regarding the association between RLS and the risk of suicide and self-harm is limited.

OBJECTIVE

To investigate the association between RLS and risk of suicide and self-harm.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was performed using Truven Health MarketScan national claims data from 2006 to 2014; the baseline data were from 2006 to 2008, and the follow-up data covered 6 years (January 1, 2009, to December 31, 2014). Included were 24 179 nonpregnant participants with RLS and 145 194 age- and sex-matched participants without RLS at baseline (2006-2008), who were free of suicide, self-harm, cardiovascular disease, or cancer at study baseline. Data analysis was performed from February 1, 2018, to January 1, 2019.

EXPOSURE

Diagnosis of RLS, as identified by the International Classification of Diseases, Ninth Revision code.

MAIN OUTCOMES AND MEASURES

Incident suicide and self-harm event, identified by the International Classification of Diseases, Ninth Revision diagnosis code.

RESULTS

Among 169 373 participants in the current analysis, the mean (SD) age was 49.4 (9.1) years; 53 426 (31.5%) participants were men. During a mean (SD) follow-up duration of 5.2 (2.2) years, 119 incident suicide and self-harm cases were identified. Individuals with RLS had a higher risk of suicide or self-harm compared with those without RLS (adjusted hazard ratio, 2.66; 95% CI, 1.70-4.15), after adjusting for lifestyle factors (eg, alcohol and obesity), presence of chronic diseases (eg, depression, insomnia, diabetes, chronic kidney disease, peripheral neuropathy, iron-deficiency anemia, and Parkinson disease), and use of medications. Excluding those with depression, insomnia, obstructive sleep apnea, and other common chronic conditions, the significant association between RLS and suicide or self-harm persisted (adjusted hazard ratio, 4.14; 95% CI, 2.17-7.92).

CONCLUSIONS AND RELEVANCE

Restless legs syndrome was associated with a high risk of suicide and self-harm, and the risk was independent of most identified diseases and conditions.

Is Restless Legs Syndrome Associated with an Increased Risk of Mortality? A Meta-Analysis of Cohort Studies

Background

Restless legs syndrome (RLS) is a common sleep disorder,. although controversial, growing evidence relates the presence of RLS to an increased risk of mortality, mainly due to cardiovascular events. The aim of this article was to review the role of RLS as a risk factor of mortality according to independent cohort studies.

Methods

We performed a literature review via PubMed database for articles relating RLS and mortality. We used the random-effects model to calculate the pooled effect estimates on mortality. Heterogeneity between studies was assessed using quantitative and qualitative analysis.

Results

Out of 100 articles identified, 13 were finally included. Although studies were heterogeneous (p = 0.001), no significant publication bias was found. When all cohort studies were considered, the random-effects model yielded a significantly increased risk of mortality in RLS versus non-RLS patients (13 studies, hazard ratio [HR] = 1.52, 95% confidence interval [CI] 1.28-1.80). However, this association was not statistically significant when only cohort studies using the international RLS diagnostic criteria were considered (5 studies, HR = 1.63, 95% CI 0.94-2.81).

Discussion

The results of this meta-analysis suggest that RLS seems to be a risk factor of mortality, although this association is conditioned by the diagnostic criteria used in the studies. Future long-term follow-up standardized mortality studies are needed to address this important question that carries potential impact on population global health.

Restless legs syndrome, periodic limb movements during sleep and cardiovascular risk

Multiple mechanisms may modulate an association between restless legs syndrome/Willis-Ekbom disease (RLS/WED) and cardiovascular disease (CVD), including chronic sleep deprivation, intermittent, periodic limb movements in sleep (PLMS)-related autonomic fluctuations and possible autonomic dysfunction intrinsically associated with RLS per se. The purpose of this paper is to review the existing RLS/WED literature focusing on the pathophysiologic evidence for possible associations between RLS/WED and PLMS with CVD and events (CVE). Specific intrinsic dysautonomic aspects of the disease, which may contribute to generating CVD, are separately discussed. The association between RLS/WED and both CV risk factors and CVD still remains elusive. Although several shared pathophysiological causes could explain these possible relationships, the emerging body of literature focusing on these disorders remains controversial. Not only longitudinal population-based studies and meta-analyses, but also more animal models and therapeutic interventions are needed in order to build a sufficiently robust body of evidence on this topic.

Restless arms syndrome: prevalence, impact, and management strategies

This literature review focuses on restless arms syndrome (RAS), an upper limb variant of restless legs syndrome (RLS). RLS, also known as Willis-Ekbom disease, is a frequently occurring neurological disorder characterized by an irresistible urge to move the lower limbs often accompanied by unpleasant sensations in the legs, worsened at rest and in the evening, improved by movement. Extension of leg restlessness to the upper limbs is frequently reported in typical patients who had RLS only in the legs and usually occurs later in the course of RLS, restlessness remaining most invalidating in the lower limbs. In RAS, the arms are predominantly affected with little or no involvement of the legs. Cases of restless shoulders syndrome or periodic arm movements without arm restlessness were not considered. A total of 9 articles with 10 cases were included and analyzed for the adherence to the five essential diagnostic criteria of the International RLS Study Group (IRLSSG) classification, as well as for the additional supportive features. All of the reported cases were classified as having definite RAS. The clinical history and disease evolution of two previously reported patients were completed and updated. Overall, the clinical picture of RAS does not differ from that of RLS, except for the symptoms localization on the upper limbs. Underlying mechanisms of the spread of RLS to upper limb restlessness and of RAS remain unknown. Whether RAS is a phenotypic variant of RLS or a separate entity needs further investigations. RAS likely remains underdiagnosed and according to IRLSSG diagnostic criteria RAS should be considered when RLS-like symptoms are present in one or both arms, especially when they have a circadian pattern and are improved by movement and dopaminergic therapy. Clinicians should be aware of this rare condition, especially as treatment using dopaminergic agonists proves to be very efficient.

Restless legs syndrome is associated with major comorbidities in a population of Danish blood donors

BACKGROUND

Restless Legs Syndrome (RLS) is characterized by uncomfortable nocturnal sensations in the legs making sedentary activities and sleep difficult, and is thus linked with psychosocial distress. Due to the symptomatology and neurobiology of RLS (disrupting brain iron and dopamine) it is likely that RLS associates with poorer health-related quality of life (HRQL) and depressive disorder. The objective of this study was to investigate the RLS-HRQL and the RLS-depressive disorder links in a generally healthy population that is not biased by medications.

METHODS

Complete data, including the Cambridge-Hopkins RLS questionnaire, the 12-item short-form standardized health survey (SF-12), the Major Depression Inventory (MDI), body mass index, smoking status, alcohol consumption, and education were available for 24,707 participants enrolled in the Danish Blood Donor Study from May 1, 2015 to February 1, 2017. Information on quality of sleep was available for all RLS cases. T-tests and multivariable logistic regression models were applied to examine the associations of RLS and MDI scores, and the physical and mental component scores (PCS and MCS) of SF-12, respectively. Analyses were conducted separately for men and women.

RESULTS

RLS associated with poorer MCS and poorer PCS. Moreover, Participants with RLS were more likely to classify with depressive disorder. Poor quality of sleep was associated with depressive disorder and poorer MCS among RLS cases, and with poorer PCS in female RLS cases.

CONCLUSION

Thus, we demonstrated that RLS is associated with a significantly lower HRQL and a higher prevalence of depressive disorder among otherwise healthy individuals.

Sleep Disturbances as a Risk Factor for Stroke

Sleep, a vital process of human being, is carefully orchestrated by the brain and consists of cyclic transitions between rapid eye movement (REM) and non-REM (NREM) sleep. Autonomic tranquility during NREM sleep is characterized by vagal dominance and stable breathing, providing an opportunity for the cardiovascular-neural axis to restore homeostasis, in response to use, distress or fatigue inflicted during wakefulness. Abrupt irregular swings in sympathovagal balance during REM sleep act as phasic loads on the resting cardiovascular system. Any causes of sleep curtailment or fragmentation such as sleep restriction, sleep apnea, insomnia, periodic limb movements during sleep, and shift work, not only impair cardiovascular restoration but also impose a stress on the cardiovascular system. Sleep disturbances have been reported to play a role in the development of stroke and other cardiovascular disorders. This review aims to provide updated information on the role of abnormal sleep in the development of stroke, to discuss the implications of recent research findings, and to help both stroke clinicians and researchers understand the importance of identification and management of sleep pathology for stroke prevention and care.

Restless legs syndrome and cerebrovascular/cardiovascular events: Systematic review and meta-analysis

OBJECTIVE

We performed a systematic review and meta-analysis to evaluate the proposed association of restless legs syndrome (RLS) with cerebrovascular/cardiovascular outcomes.

METHODS

We calculated the corresponding odds ratios on the prevalence of cerebrovascular/cardiovascular risk factors and standardized mean differences on the reported mean age at baseline between RLS patients and controls. We also calculated the corresponding risk ratios and adjusted for potential confounders hazard ratios (HRs_adjusted ) on the reported outcomes of interest between RLS patients and controls.

RESULTS

We identified 8 eligible studies (644 506 patients, mean age: 60.2 years, 36.2% males; 3.3% with RLS). RLS patients were found to have significantly higher prevalence of hypertension (P = .002), diabetes (P = .003) and hyperlipidemia (P = .010) compared to controls. In the unadjusted analyses of prospective observational studies, RLS patients were found to have significantly higher risk for cerebrovascular ischaemia (P = .01) and all-cause mortality (P = .04) compared to controls during follow-up, while in the adjusted for potential confounders analyses RLS patients were only found to have a higher risk of all-cause mortality (HR adjusted=1.52, 95% CI: 1.17-1.97, P = .002).

CONCLUSIONS

The present report does not provide evidence for an increased risk of cerebrovascular and cardiovascular events in RLS patients, which highlights the vast presence of confounding factors.

Prospective study of restless legs syndrome and total and cardiovascular mortality among women

OBJECTIVE

We prospectively examined whether women with physician-diagnosed restless legs syndrome (RLS) had a higher risk of total and cardiovascular disease (CVD) mortality relative to those without RLS.

METHODS

The current study included 57,417 women (mean age 67 years) from the Nurses' Health Study without cancer, renal failure, and CVD at baseline (2002). Main outcomes were total and CVD mortality. We used the Cox proportional hazards model to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and CVD-specific mortality based on RLS status, adjusting for age, presence of major chronic diseases, and other potential confounders.

RESULTS

We documented 6,448 deaths during 10 years of follow-up. We did not observe a significant association between presence of physician-diagnosed RLS and high risk of total mortality (adjusted HR 1.15, 95% CI 0.98-1.34). When cause-specific mortality was studied, participants with RLS had a significantly higher risk of CVD mortality (adjusted HR 1.43, 95% CI 1.02-2.00) relative to those without RLS after adjustment for potential confounders. Longer duration of RLS diagnosis was significantly associated with a higher risk of CVD mortality (p for trend = 0.04). Excluding participants with common RLS comorbidities strengthened the association between RLS and total (adjusted HR 1.43, 95% CI 1.03-1.97) and CVD mortality (adjusted HR 2.27, 95% CI 1.21-4.28). However, we did not find a significant association between RLS and mortality due to cancer and other causes.

CONCLUSIONS

Women with RLS had a higher CVD mortality rate, which may not be fully explained by common co-occurring disorders of RLS.

Survival of Dialysis Patients with Restless Legs Syndrome: A 15-Year Follow-Up Study

BACKGROUND

Restless legs syndrome, also known as Willis/Ekbom disease (RLS/WED), is a sleep-related, sensorimotor disorder with a high prevalence among end-stage renal disease (ESRD) patients undergoing haemodialysis (HD) (about 15-40%). Whether RLS/WED in uremic patients influences cardiovascular morbidity and mortality remains a matter of controversy. The aim of this study was to evaluate the relationship of RLS/WED and mortality in a population of chronically dialyzed patients.

METHOD

In 1996, we studied 128 patients with ESRD undergoing HD; 47 subjects (36.7%) complained RLS/WED symptoms. Fifteen years later we evaluated the mortality of this population. No clinical follow-up examination of the uremic population was made. The Kaplan-Maier curves in dialysis patients with or without RLS/WED (control group matched for age) were constructed for all-cause mortality and compared using log-rank test.

RESULTS

The Kaplan-Maier curves disclosed a lower mortality rate in the uremic patients with RLS/WED than in those without RLS/WED (p = 0.04). In our analysis, the mortality rate was not influenced by RLS/WED severity (p = 0.11) or gender (p = 0.15). No difference among the causes of death was found in the 2 groups.

CONCLUSIONS

Our study suggests that mortality in ESRD patients is not influenced by concomitant RLS/WED. After a 15-year follow-up, survival rates in our cohort were significantly longer in uremic subjects with RLS/WED than in those without RLS/WED. Finally, we found no relationship between RLS/WED severity and mortality.

Insomnia and Relationship With Immunosuppressant Therapy After Lung Transplantation

BACKGROUND

Lung transplant recipients are at high risk of developing sleep disorders such as insomnia, but the prevalence and features are currently poorly characterized within this population. Since these disorders are associated with increased morbidity and mortality, it is important to identify them to optimize the care of lung transplant recipients. We sought to evaluate the prevalence of insomnia within our university-based lung transplant clinic and determine whether a relationship exists between insomnia and exposure to immunosuppressant medications following transplantation.

METHODS

Participants were recruited through the University of Wisconsin Hospital and Clinics Lung Transplant Clinic (N = 125). Participants (n = 92) completed the adult sleep history questionnaire, which included the Insomnia Severity Index (ISI) to assess for insomnia (defined as ISI score >10). Cumulative tacrolimus exposure was determined in 73 patients by performing an area under the curve calculation to assess for a potential relationship between tacrolimus exposure and insomnia.

RESULTS

The prevalence of insomnia was 40% within this population. Although no difference in time since transplant was found, cumulative mean ± standard error of the mean tacrolimus exposure was significantly higher in patients with insomnia versus those without insomnia (17 190 ± 1673 ng·d/mL vs 12 130 ± 1630 ng·d/mL, respectively; P = .04). Estimated tacrolimus exposure was not greater with increasing frequency of insomnia complaints (analysis of variance P = .54).

CONCLUSION

In our population, insomnia is common after lung transplantation, with prevalence greater than the general population. Higher cumulative exposure to tacrolimus may contribute to insomnia in this group. Future research should investigate the relationship between immunosuppressant therapy and development of sleep disorders.

Prevalence and associated comorbidities of restless legs syndrome (RLS): Data from a large population-based door-to-door survey on 19176 adults in Tehran, Iran

BACKGROUND

Discrepancies have been reported in the prevalence rate of restless legs syndrome (RLS) among different ethnic groups and geographic populations. Furthermore, there are disagreements on determinant factors and associated comorbidities of RLS. We aimed to estimate prevalence of RLS and investigate its associated comorbid conditions and risk factors in a large population-based door-to-door survey.

METHODS

Following a multistage random sampling from the households lived in 22 urban districts of Tehran, Iran, 19176 participants with ≥30 years of age were recruited. Trained surveyors filled study checklist consisting of baseline characteristics, risk factors and comorbidity profile and the International RLS Study Group (IRLSSG) diagnostic criteria through face-to-face interviews.

RESULTS

In total, 1580 individuals were positively screened for RLS resulting in a standardized prevalence rate of 60.0/1000. There was a gradual increase in RLS prevalence by advancing age, however, sex difference disappeared after adjustment. Parkinsonism [adjusted odds' ratio (adj-OR) = 7.4 (95% CI: 5.3-10.4)], peripheral neuropathy [adj-OR = 3.7 (95% CI: 3.3-4.1)], subjective cognitive impairment (SCI) [adj-OR = 3.1 (95% CI: 2.7-3.4)], acting out dreams [adj-OR = 2.8 (95% CI: 2.5-3.2)], hyposmia [adj-OR = 2.5 (95% CI: 2.2-2.9)], active smoking [adj-OR = 1.5 (95% CI: 1.3-1.9)] and additional number of cardiometabolic diseases associated with higher risk of RLS [adj-OR = 1.6 (95% CI: 1.2-2.3)].

CONCLUSION

Our findings showed that neuro-cognitive co-morbidities such as parkinsonism, peripheral neuropathy, SCI, acting out dreams and hyposmia as well as cardio-metabolic risk factors and diseases were independent determinants of RLS. It is recommended to screen individuals with either these comorbid conditions for RLS or the ones with RLS for the accompanying diseases.

Prognostic value of restless legs syndrome in hemodialysis patients: a systematic review and meta-analysis

BACKGROUND

Previous studies have revealed that restless legs syndrome (RLS) not only is frequently prevalent in dialysis patients but also increases the risk of death in dialysis patients, especially in hemodialysis (HD) patients. However, inconsistent results also still exist, having attracted confusion and discussion. Owing to mixed and inconclusive results, we conducted to perform the comprehensive meta-analysis to evaluate the potential prognostic value of RLS in HD patients.

MATERIALS AND METHODS

We conducted a systematic literature search using electronic databases (PubMed, Ovid, Embase and Web of Science) to identify relevant studies reporting on all-cause mortality and cardiovascular (CV) events in HD patients suffering from RLS. We searched the literature published up to December 5, 2016, or earlier. We used both fixed- and random-effects models to calculate the overall effect estimate. An I²>50% indicates at least moderate statistical heterogeneity. A sensitivity analysis and subgroup analysis were performed to find the origin of heterogeneity.

RESULTS

A total of four studies including 1,839 patients found that there was no significant association between RLS and all-cause mortality (hazard ratio [HR]: 1.649; 95% confidence interval [CI]: 0.778-3.496) and CV events (HR: 0.863; 95% CI: 0.600-1.127) in HD patients. Heterogeneity among the studies was observed for all-cause mortality (I²=80.7%, P=0.001).

CONCLUSION

Our meta-analysis suggests that there was no significant effect of RLS on all-cause mortality and CV events in HD patients. Therefore, large-scale and well-designed studies are needed to validate the association between RLS and the risk of death in HD patients.

Prevalence of restless legs syndrome in chronic kidney disease: a systematic review and meta-analysis of observational studies

INTRODUCTION

Nowadays prevalence of restless legs syndrome (RLS) in chronic kidney disease (CKD) patients was reported in many studies, while the results varied. The aim of our study was to investigate the prevalence of RLS in this population, considering different data collecting measures and diagnostic criteria.

METHODS

MEDLINE, Embase, PsycINFO, and Scopus databases were searched for relevant studies. We limited the analyses to studies using clinical interview or questionnaire for diagnosis. Univariate meta-regression analysis was preformed to assess the effects of the disease-related covariates on prevalence estimates. Comprehensive Meta-Analysis 2.0 was used to perform the meta-analysis.

RESULTS

Fifty-one studies were included in the analysis. Prevalence of RLS was varied by renal function and diagnostic methods. Overall prevalence in CKD populations was 24.2% (95%CI, 20.1-28.7). Pooled prevalence of RLS was higher in patients diagnosed by questionnaire than by clinical interview [26.2% (95%CI, 17.9-36.5) vs. 23.6% (95%CI, 19.6-28.1)]. When grouped by CKD setting, the prevalence was 28.4% (95%CI, 24.6-32.6) in dialysis patients, followed by early stages patients [9.9% (95%CI, 5.4-17.5)], and kidney transplant recipients [6.7% (95%CI, 5.6-7.8)].

CONCLUSIONS

Our meta-analysis suggested that more than one-quarter of CKD sufferers, especially those who were on dialysis, were plagued by RLS. Higher sensitivity of diagnostic criteria in interview may be valuable for timely treatment.

Prevalence of restless legs syndrome during detoxification from alcohol and opioids

BACKGROUND AND AIMS

Restless legs syndrome (RLS) is a movement disorder associated with adverse health outcomes and decreased quality of life. Small case series suggest that symptoms of RLS occur during opioid withdrawal. However, the prevalence is unknown.

METHODS

We conducted an observational study to determine the prevalence of RLS among inpatients patients receiving buprenorphine detoxification from opioids. To assess the specificity of RLS to opioid detoxification, we also evaluated patients receiving detoxification from alcohol as a comparison group. The diagnosis of RLS was established using a validated questionnaire.

RESULTS

The sample consisted of 124 adults with primary opioid use disorder and 180 with primary alcohol use disorder. In the total sample, 33.6% met a likely RLS diagnosis: 50.8% of those with opioid use disorder and 21.7% of those with alcohol use disorder (χ² = 27.96[1,304] p < .001). In the logistic regression analysis controlling for socio-demographic and clinical variables, diagnosis of opioid use disorder was associated with more than twice the likelihood of RLS diagnosis (OR=2.05, 95% CI 1.09-3.88) relative to diagnosis of alcohol use disorder.

CONCLUSIONS

Approximately half of patients undergoing inpatient opioid detoxification exhibited the symptoms characteristic of RLS. We believe that these data support the existence of a secondary form of RLS associated with opioid withdrawal.

Restless Legs Syndrome in Patients With Chronic Kidney Disease

Symptoms of restless legs syndrome (RLS) are common in patients with chronic kidney disease (CKD) on dialysis; symptoms of RLS are estimated to affect up to 25% of patients on dialysis when the international RLS diagnostic criteria are applied. RLS is a neurologic disorder with a circadian rhythmicity characterized by an overwhelming urge to move the legs during rest, which can be relieved temporarily by movement. RLS has been associated with an increase in sleep disturbance, higher cardiovascular morbidity, decreased quality of life, and an increased risk of death in patients with CKD. Although the exact pathophysiology of RLS is unknown, it is thought to involve an imbalance in iron metabolism and dopamine neurotransmission in the brain. The symptoms of moderate to severe RLS can be treated with several pharmacologic agents; however, data specific to patients on dialysis with RLS are lacking. The purpose of this article is to examine the relationship between, and complications of, RLS and CKD both in dialysis and nondialysis patients, and discuss the treatment options for patients on dialysis with RLS.

Parathyroidectomy Improves Restless Leg Syndrome in Patients on Hemodialysis

Background

Restless leg syndrome (RLS) is a sleep disorder with high prevalence among patients on hemodialysis. It has been postulated that high phosphate and high parathyroid hormone may be implicated in its pathogenesis. Standard international criteria and face-to-face interview are not always applied.

Methods

this was an interventional prospective study in which 19 patients (6 men, aged 48±11 years) with severe hyperparathyroidism were evaluated. RLS diagnosis and rating scale were accessed based on the International RLS Study Group pre- and post-parathyroidectomy. Patients also underwent standard polysomnography.

Results

At baseline, RLS was present in 10 patients (52.6%), and pain was the most reported symptom associated with the diagnosis. Patients with RLS had higher serum phosphate (p = 0.008) that remained independently associated with RLS in a logistic regression model, adjusted for hemoglobin, age and gender (HR = 7.28;CI = 1.14–46.3, p = 0.035). After parathyroidectomy, there was a reduction of serum parathyroid hormone, phosphate, calcium and alkaline phosphatase, and an increase of 25(OH)-vitamin D, and Fetuin-A. Parathyroidectomy alleviated RLS (from 52% to 21%; p = 0.04), which was accompanied by a decrease in severity scale, in association with relief of pain and pruritus. Polysomnography in these patients showed an improvement of sleep parameters as measured by sleep efficiency, sleep latency and percentage of REM sleep.

Conclusion

RLS is associated with high levels of phosphate in patients with severe secondary hyperparathyroidism on hemodialysis. Pain is most reported complain in these patients. Parathyroidectomy provided an opportunity to relief RLS. Whether the reduction of serum phosphorus or parathyroid hormone contributed to this improvement merits further investigation.

Restless Legs Syndrome in Patients with Hypertension and Diabetes Mellitus

Aim:

The aim of this study was to analyze frequency of restless legs syndrome (RLS) in patients with hypertension and diabetes mellitus.

Patients and Methods:

It was analyzed 120 subjects (from Health Center Živinice/Family Medicine Department) through a survey conducted in the period from March to June 2015, of which 30 (8 men/22 women). Subjects were 30 patients with longtime hypertension (HT)(18 men/12 women), 30 patients with diabetes mellitus (DM) type I or II (9 men/21 women), 30 patients with long standing DM type I or II and HT (12 men /18 women), and 30 control subjects (12 men/18 women). RLS were evaluated by questionnaire - International RLS Study Group Criteria. The average age of patients in the group with HT was 58.70 ± 9.07, in the group with DM 48.43 ± 15.37, and in the group of patients with HT and DM 63.90 ± 7.49 years. In the control group mean age was 52.76 ± 14.83 years. Statistical data were analyzed in Excel and SSPS statistical program.

Results:

RLS was identified in 10 (30%) of those with HT; 7 (21%) in patients with DM, and 10 (30%) in patients with HT+DM. In the control group RLS was verified in 4 (12%) patients. Comparing the results, it was observed significant difference between the HT and the control group (p=0.0012) and HT+ DM and control group (p=0.0012). The frequency of RLS between DM and the control group was not significantly significant (p=0.107).

Conclusion:

RLS is frequent in patients with hypertension (30%), hypertension+ diabetes mellitus (30%), and patients with DM (21%).

Symptom Severity of Restless Legs Syndrome Predicts Its Clinical Course

OBJECTIVE

This study examines the clinical course of restless legs syndrome according to its severity and factors associated with the remission of restless legs syndrome symptoms.

METHODS

The remission or persistence of restless legs syndrome symptoms was investigated by considering patients with restless legs syndrome at the sleep clinic of Seoul National University Bundang Hospital. All subjects were observed for at least 18 months, and an incidence of remission was defined as having no restless legs syndrome symptoms for at least 1 year. Restless legs syndrome severity was evaluated by the International Restless Legs Syndrome Study Group Rating Scale.

RESULTS

A total of 306 patients participated in this study. Over the observation periods of 4.1 ± 1.6 years, the cumulative incidence of remission is 32.5% (95% confidence interval [CI], 27.0-38.0) and decreased with baseline restless legs syndrome severity (P < .001): 60% (95% CI, 44.9-75.1), 44% (95% CI, 34.4-53.6), and 16.7% (95% CI, 10.6-22.8) in mild, moderate, and severe to very severe restless legs syndrome cases, respectively. Most cases of remission (82/96) were observed within 1 year, and the remission occurred sooner for mild restless legs syndrome. The hazard ratios of remission by Cox proportional hazards model were lower for moderate (0.556; 95% CI, 0.340-0.909) and severe to very severe (0.193; 95% CI, 0.108-0.343) restless legs syndrome than for mild restless legs syndrome. The remission incidence was lower for those patients who had a family history of restless legs syndrome and were older at restless legs syndrome diagnosis.

CONCLUSIONS

Mild restless legs syndrome severity, no family history, and young age at restless legs syndrome diagnosis were significant predictors of restless legs syndrome remission. More than 80% of patients with severe restless legs syndrome showed a chronic clinical course.

Hyperdopaminergism in lenticulostriate stroke-related restless legs syndrome: an imaging study

OBJECTIVE

The pathophysiology of restless legs syndrome (RLS) involves a dopaminergic dysregulation that remains poorly understood, with controversial data from the literature. Stroke-related RLS is a rare condition that involves primarily the basal ganglia, the paramedian pons, and the thalamus. Given these elements, we studied dopaminergic metabolism in patients with RLS secondary to lenticulostriate infarction using structural and nuclear imaging in the striatum ipsilateral to the infarction area, as compared to the contralateral side. We hypothesized that dopaminergic metabolism would be impaired in the striatum ipsilateral to stroke.

METHODS

In this observational case-control study, we aimed to prospectively include patients with RLS secondary to lenticulo-striate infarction, for analyses of dopamine dysfunction ipsilateral to stroke as compared to the contralateral striatum and to a control population. Four patients fulfilled inclusion criteria with either de novo RLS or major exacerbation of RLS existing prior to stroke, and all four patients were included. Structural imaging was performed using brain magnetic resonance imaging, and the stroke-induced metabolic modifications were assessed by ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET). Dopamine reuptake via DAT was explored using ¹²³I-FP-CIT SPECT. PET with ¹⁸F-FDOPA was used to evaluate the functional integrity of the presynaptic dopaminergic synthesis.

RESULTS

The only structure damaged in all patients was the body of the caudate nucleus, right-sided for three and left-sided for one, as illustrated by magnetic resonance imaging. ¹⁸F-FDG PET showed a hypometabolism in the infarcted area, the ipsilateral thalamus, and the contralateral cerebellum. All patients displayed, in the ipsilateral putamen, increased dopaminergic tone.

CONCLUSION

The present findings suggest that increased dopaminergic tone in the striatum may participate in the pathogenesis of RLS. These observations should encourage further research on RLS symptomatic with well-defined lesions as a promising way to further improve our understanding of its pathophysiology.

Association of incident restless legs syndrome with outcomes in a large cohort of US veterans

Restless legs syndrome is a common sleep disorder, but there is a paucity of large cohort studies examining the association of restless legs syndrome with clinical outcomes, including all-cause mortality, incident coronary heart disease, stroke and chronic kidney disease. From a nationally representative prospective cohort of over 3 million US veterans [93% male, median follow-up time of 8.1 years (interquartile range: 7.0-8.5 years)] with baseline estimated glomerular filtration rate ≥ 60 mL min(-1) 1.73 m(-2), a propensity-matched cohort of 7392 patients was created, and the association between incident restless legs syndrome and the following was examined: (1) all-cause mortality; (2) incident coronary heart disease; (3) incident strokes; and (4) incident chronic kidney disease defined as estimated glomerular filtration rate <60 mL min(-1) 1.73 m(-2). Associations were examined using Cox models. The mean ± SD age of the propensity-matched cohort at baseline was 59 ± 12 years; 89 and 8% of patients were white and black, respectively; 31% of the patients were diabetic; and the mean baseline estimated glomerular filtration rate was 83.9 ± 15.1 mL min(-1) 1.73 m(-2). Propensity matching resulted in a balanced cohort, with the disappearance in baseline differences in comorbidities. Compared with restless legs syndrome-negative patients, incident restless legs syndrome was associated with 88% higher mortality risk [hazard ratio and 95% confidence interval: 1.88 (1.70-2.08)], and almost four times higher risk of coronary heart disease and stroke [hazard ratio: 3.97 (3.26-4.84) and 3.89 (3.07-4.94), respectively]. The risk of incident chronic kidney disease was also significantly higher in incident restless legs syndrome patients [hazard ratio: 3.17 (2.74-3.66)] compared with restless legs syndrome-negative counterparts. In this large and contemporary cohort of US veterans, incident restless legs syndrome was associated with higher risk of mortality, incident coronary heart disease, stroke and chronic kidney disease.

Impaired vascular endothelial function in patients with restless legs syndrome: a new aspect of the vascular pathophysiology

BACKGROUND

Restless legs syndrome (RLS) is a common sleep disorder in which patients feel unpleasant leg sensations and the urge to move their legs during rest, particularly at night. Leg movement improves these symptoms. Although several studies have demonstrated an association between cardiovascular disease and RLS, the mechanisms underlying this relationship remain unclear. Recent studies have shown changes in the peripheral microvasculature, including altered blood flow and capillary tortuosity, and peripheral hypoxia. Vascular endothelial dysfunction can be assessed noninvasively with ultrasound measurements of brachial artery flow-mediated dilatation (FMD). Therefore, this study investigated FMD in RLS patients to determine the involvement of microvascular alterations in this disorder.

METHODS

The study enrolled 25 drug-naïve RLS patients and 25 sex- and age-matched controls and compared the FMD values of the two groups. RLS was diagnosed according to the criteria of the International Restless Legs Syndrome Study Group.

RESULTS

FMD was significantly lower in the RLS patients (6.6 ± 1.2%) compared to the controls (8.4 ± 1.8%; p<0.05) and the RLS patients showed a weak, negative correlation between RLS severity and FMD (r=-0.419, p=0.04). Multivariate linear regression analysis revealed that RLS (B=-1.87, 95% confidence interval [CI] -2.72 to -1.02; p<0.001) and age (B=-0.06; 95% CI -0.12 to -0.02; p<0.001) were significantly and inversely correlated with FMD.

CONCLUSIONS

This study demonstrated that RLS patients have poorer vascular endothelial function than normal healthy subjects and provides further evidence supporting the involvement of peripheral systems in the generation of RLS.

The Humanistic and Economic Burden of Restless Legs Syndrome

Objectives

To evaluate the humanistic and economic burden of a restless legs syndrome (RLS) diagnosis with regard to health-related quality of life, work productivity loss, healthcare resource use, and direct and indirect costs.

Study Design

Self-reported data came from the 2012 National Health and Wellness Survey (NHWS), a large, annual, nationally representative cross-sectional general health survey of US adults.

Methods

RLS patients (n = 2,392) were matched on demographic and health characteristics to Non-RLS respondents via propensity score matching differences between groups were tested with Bivariate and multivariable analyses.

Results

RLS patients had significantly lower health-related quality of life scores: Mental Component Summary (44.60 vs. 48.92, p<.001), Physical Component Summary (40.57 vs. 46.78, p<.001), Health Utilities (.63 vs. .71, p<.001) and higher levels of work productivity loss in the past seven days including absenteeism (8.1% vs. 9.3%, p<.001), presenteeism (26.5% vs. 15.8%, p<.001), and overall productivity loss (30.1% vs. 18.1%, p<.001) as well as general activity impairment (46.1% vs. 29.7%, p<.001). RLS patients had significantly higher healthcare resource use in the past 6 months than non-RLS patients: healthcare provider visits (7.46 vs. 4.42%, p<.001), ER visits (0.45 vs. 0.24, p<.001), and hospitalizations (0.24 vs. 0.15, p<.001). RLS patients also had higher estimated direct and indirect costs than non-RLS patients. Finally, it was found that across outcomes increasing severity is associated with increased economic and humanistic burden for RLS patients.

Conclusions

RLS patients suffer a greater humanistic and economic burden than those without RLS. Moreover as severity increases so does the burden of RLS.

Risk of Cardiovascular Disease Associated with a Restless Legs Syndrome Diagnosis in a Retrospective Cohort Study from Kaiser Permanente Northern California

INTRODUCTION

Recent cross-sectional studies suggest that restless legs syndrome (RLS) may be associated with an increased prevalence of cardiovascular disease (CVD) comorbidity or risk factors. We evaluated whether primary or secondary RLS was associated with an increased risk of incident cardiovascular disease in a retrospective cohort study within Kaiser Permanente Northern California (KPNC).

METHODS

We identified members of KPNC with primary RLS and secondary RLS between 1999 and 2008 by an algorithm that incorporated longitudinal clinical records related to the diagnosis and treatment of RLS and comorbidities. We then matched each RLS case with up to 50 individuals with no clinical records of RLS by age, sex, race/ethnicity, zip code, and membership duration. For the analyses we excluded any individual with coronary artery disease (CAD: angina, acute myocardial infarction, coronary revascularization procedure, CAD death), CVD (CAD plus stroke), and hypertension at baseline. New cardiovascular events were determined from clinical records. Follow-up ended at an outcome event, disenrollment from KPNC, or death, whichever occurred earliest. There were over 473,358 person-y of follow-up in this cohort analysis with a mean follow-up time of 3.91 y and range from 6 mo to 12 y. Survival analysis techniques, including survival curves and proportional hazard regression models, were used to assess the association between RLS status and CVD.

RESULTS

There were 7,621 primary RLS and 4,507 secondary RLS cases identified and included in the study. In general, primary RLS cases were younger and had less comorbidity than secondary RLS cases. During the follow-up period, CVD was diagnosed in 478 primary RLS cohort members, CAD was diagnosed in 310, and hypertension events were identified in 1,466. Diagnosis in secondary RLS cohort members was made during the follow-up period with 451, 338, and 598 CVD, CAD, and hypertension events, respectively. Subjects with primary RLS had a similar risk of incident CVD (hazard ratio (HR) = 0.95; 95% confidence interval (CI) = 0.86-1.04) and CAD (HR = 0.99; 95% CI = 0.89-1.13) to the comparison cohort, with a slight elevation in the risk of hypertension events (HR = 1.19; 95% CI = 1.12-1.25), after multivariable adjustment. Individuals classified as secondary RLS had a significant increased risk of CVD (HR = 1.33; 95% CI = 1.21-1.46), CAD (HR = 1.40; 95% CI = 1.25-1.56), and hypertension (HR = 1.28; 95% CI = 1.18-1.40).

CONCLUSION

Primary restless legs syndrome (RLS) was not associated with new-onset cardiovascular disease (CVD) or coronary artery disease (CAD) but was associated with a slight increased risk of hypertension. In contrast, secondary RLS was associated with an increased risk of CVD, CAD, and hypertension.

Restless Legs Syndrome and Hypertension in Mexican Women

Background

RLS is a common chronic disorder characterized by an irresistible need to move the lower limbs that affects sleep. Poor sleep has been associated with increased blood pressure (BP). Thus, we evaluated the cross-sectional relationship between RLS and hypertension (HTN) in a large cohort study in Mexico.

Methods

In 2011, 54,925 female participants from the Mexican Teachers' Cohort responded to a four-item questionnaire based on the International Restless Legs Syndrome Study Group's minimal diagnostic criteria. Women also reported diagnosis and treatment of HTN. We used multivariable logistic regression models to estimate prevalence odds ratios (ORs) for HTN, adjusting for lifestyle and dietary factors. We also estimated adjusted prevalence ORs for HTN by frequency of RLS symptoms.

Results

We identified 9,230 cases (17%) of RLS, and the prevalence of HTN was 13.1% among women with RLS and 9.4% among those without RLS. The multivariable-adjusted prevalence OR for HTN comparing women with to those without RLS was 1.18 (95% confidence interval [CI]: 1.10-1.26). Compared to those without RLS, the prevalence OR of HTN in women reporting a symptom frequency of once a month or less was 1.14 (95% CI: 1.00-1.30); among those with symptoms two to four times a month, the OR was 1.17 (95% CI: 1.05-1.30); and for those with symptoms at least two times a week, the OR was 1.22 (95% CI: 1.10-1.35).

Conclusion

We observed an association between RLS and HTN. Future studies should evaluate the impact of treating RLS on BP.

Restless legs syndrome: clinical presentation diagnosis and treatment

Restless legs syndrome (RLS) is a circadian disorder of sensory-motor integration that may be related to genetically determined dysregulation of iron transport across the blood-brain barrier. Dopamine agonists (DAs) have been considered the first-line therapy, but with the growing appreciation of problems associated with long-term treatment, particularly augmentation and impulse control disorder, alpha-2-delta drugs, such as gabapentin, are now considered the first line of treatment in patients with troublesome RLS. Opioids can be considered as an alternative therapy, particularly in patients with DA-related augmentation. In more severe cases, a combination therapy may be required. Intravenous iron therapy may be considered on those patients with refractory RLS.

Brazilian consensus on guidelines for diagnosis and treatment for restless legs syndrome

The Consensus on restless legs syndrome is an effort of neurologists from several Brazilian states, which tirelessly reviewed the literature of recent years in search of evidence, both in regard to diagnosis and treatment, according to the Oxford Centre for Evidence-based Medicine.

Genetic variants associated with sleep disorders

OBJECTIVE

The diagnostic boundaries of sleep disorders are under considerable debate. The main sleep disorders are partly heritable; therefore, defining heritable pathophysiologic mechanisms could delineate diagnoses and suggest treatment. We collected clinical data and DNA from consenting patients scheduled to undergo clinical polysomnograms, to expand our understanding of the polymorphisms associated with the phenotypes of particular sleep disorders.

METHODS

Patients at least 21 years of age were recruited to contribute research questionnaires, and to provide access to their medical records, saliva for deoxyribonucleic acid (DNA), and polysomnographic data. From these complex data, 38 partly overlapping phenotypes were derived indicating complaints, subjective and objective sleep timing, and polysomnographic disturbances. A custom chip was used to genotype 768 single-nucleotide polymorphisms (SNPs). Additional assays derived ancestry-informative markers (eg, 751 participants of European ancestry). Linear regressions controlling for age, gender, and ancestry were used to assess the associations of each phenotype with each of the SNPs, highlighting those with Bonferroni-corrected significance.

RESULTS

In peroxisome proliferator-activated receptor gamma, coactivator 1 beta (PPARGC1B), rs6888451 was associated with several markers of obstructive sleep apnea. In aryl hydrocarbon receptor nuclear translocator-like (ARNTL), rs10766071 was associated with decreased polysomnographic sleep duration. The association of rs3923809 in BTBD9 with periodic limb movements in sleep was confirmed. SNPs in casein kinase 1 delta (CSNK1D rs11552085), cryptochrome 1 (CRY1 rs4964515), and retinoic acid receptor-related orphan receptor A (RORA rs11071547) were less persuasively associated with sleep latency and time of falling asleep.

CONCLUSIONS

SNPs associated with several sleep phenotypes were suggested, but due to risks of false discovery, independent replications are needed before the importance of these associations can be assessed, followed by investigation of molecular mechanisms.