The prevalence of restless legs syndrome in Taiwanese adults

Prevalence of restless legs syndrome in adults with epilepsy: A systematic review and meta-analysis of observational studies

INTRODUCTION

Epilepsy is a common neurological disorder that significantly contributes to the worldwide disease burden. Restless legs syndrome is sleep-related movement disorder that causes uncomfortable sensations in the legs with an irresistible urge to move them. The aim of this study is to comprehensively assess the current evidence to estimate the prevalence of restless legs syndrome (RLS) in adults with epilepsy (AWE) and to compare it to healthy controls.

METHODS

PubMed, Medline, Scopus, and Web of Science databases were searched for observational studies reporting the prevalence of RLS in AWE. The modified Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of the studies. Comprehensive Meta-Analysis software (version 3.0) was used to perform data analysis. The heterogeneity of the studies was assessed using the I2 index. The pooled prevalence of RLS in AWE and the odds ratio were calculated based on the random-effect model. Sensitivity analysis was assessed. A funnel plot and Egger's test were used to investigate publication bias. Subgroup analysis and univariate meta-regression analysis were done.

RESULTS

Based on the analysis of 17 studies (2262 AWE patients), the prevalence of RLS was 14.9 % (95%CI, 10.4%-21 %). This rate was highest in the Americas (35.3 %; 95 % CI: 19.7-54.9 %) and lowest in Asian countries (11.6 %). The risk of RLS was significantly higher in AWE patients compared to health controls (12 studies, OR = 2.09; 95 % CI: 1.53-2.85, I2 = 91.69 %, P < 0.001). subgroup analysis showed Variations in RLS rates between studies depending on quality scores, methodology, and diagnostic criteria. The funnel plot and Egger's test suggest there was publication bias. Sensitivity analysis showed that none of the studies on their own significantly affected the results.

CONCLUSIONS

This meta-analysis provides the first pooled estimate of RLS prevalence in AWE. RLS occurs in 15 out of every 100 AWE patients, and the risk is high compared to healthy controls. However, the findings need to be confirmed in future studies owing to limitations in the analysis and study design.

Coexistence of periodic limb movements during sleep with restless legs syndrome and its association with hypertension in Japanese patients

BACKGROUND

Caucasian patients with restless legs syndrome (RLS) frequently exhibit periodic limb movements during sleep (PLMS), which may increase the risk of hypertension. We evaluated the positivity rate of PLMS and factors associated with positivity in Japanese patients with RLS, and tested whether the complications of PLMS are associated with the presence of hypertension.

METHODS

We retrospectively investigated polysomnographic data and the presence or absence of hypertension in patients with RLS. Patients with systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg or those taking antihypertensive medication were categorized as the group with hypertension.

RESULTS

Among 468 patients, 200 (42.7%) had periodic limb movement index (PLMI) values ≥ 15/h and 108 (23.1%) met the criteria of positivity for hypertension. Multiple logistic regression analysis revealed that only higher age was significantly associated with PLMI values ≥ 15/h. Multiple linear regression analyses of factors associated with an increased PLMI also showed that increased PLMI was significantly correlated with higher age and male sex, but not with the international restless legs scale scores. Multiple logistic regression analysis also revealed that higher age and body mass index, not PLMI values ≥ 15/h, were significantly associated with the presence of hypertension.

CONCLUSION

The PLMS-positivity rate may be lower in Japanese patients with RLS than in Caucasian patients, and it increases with age and male sex, but not with the severity of the disorder. Furthermore, PLMS complications were not associated with the risk of hypertension in Japanese patients with RLS.

Worldwide estimation of restless legs syndrome: a systematic review and meta-analysis of prevalence in the general adult population

This systematic review, meta-analysis and meta-regression assessed the prevalence of restless legs syndrome (RLS) in the general adult population. Studies identified in Scopus, PubMed, Web of Science, and PsycInfo between January 2000 and February 2022 were included if they used a case-control or cross-sectional design and reported data regarding the prevalence of RLS. The protocol was pre-registered in the International Prospective Register of Systematic Reviews (PROSPERO; CRD42022300709). A total of 97 studies including 483,079 participants from 33 different countries met the eligibility criteria. The Newcastle Ottawa Scale was used to evaluate the methodological quality, and the fill-and-trim method was used to correct probable publication bias, while the jack-knife method was performed to assess small study effect. The corrected overall pooled prevalence of RLS was 3% (95% confidence interval [CI] 1.4%-3.8%). The pooled prevalence of RLS syndrome was affected by methodological quality (no data from non-respondents in the included studies), gender (higher among women), study design (lower prevalence in case-control versus cohort and cross-sectional studies). The figures for corrected pooled prevalence among men, women, alcohol consumers and smokers were 2.8% (95% CI 2%-3.7%); 4.7% (95% CI 3.2%-6.3%); 1.4% (95% CI 0%-4.2%); and 2.7% (95% CI 0%-5.3%), respectively. The prevalence among male and female participants was lower in community-based versus non-community-based studies. Moreover, the prevalence was higher in developed versus developing countries and among elders versus adults. In conclusion, RLS is a common disorder in the general adult population, with a higher prevalence in women; however, prevalence data are affected by study design and quality.

Is Restless Legs Syndrome De Facto Thyroid Disease?

While a primary role in the pathogenesis of restless legs syndrome (RLS) has been attributed to dysfunction of the dopaminergic system and impaired iron metabolism (particularly in the central nervous system), it has been hypothesized that an imbalance between thyroid hormones and dopaminergic activity may be the starting point for all aspects of RLS. Although this hypothesis was proposed more than a decade ago, it has not yet been verified beyond doubt. The main aim of this study is to compare the prevalence of RLS in a population of patients with the most common thyroid gland diseases with a population of individuals with a healthy thyroid gland. The study included 237 participants divided into smaller groups according to the thyroid disease concerning them. Each participant had a laboratory diagnosis, an ultrasound scan and an assessment of the fulfilment of RLS criteria according to the International Restless Legs Syndrome Study Group (IRLSSG) criteria. The results obtained were subjected to statistical analysis. RLS is significantly more common in patients with known thyroid disease; Hashimoto’s disease, among others, manifests a 2.56× higher risk of a positive diagnosis for RLS than the general population. The association of RLS with thyroid disease is notable, although it is difficult to conclude unequivocally that there is a cause-and-effect relationship between the two. Further investigation into a potentially autoimmune cause of restless legs syndrome should be considered.

Prevalence and Determinants of Restless Legs Syndrome (Willis-Ekbom Disease) in an Older Greek Population

OBJECTIVES

The present study aimed to explore the descriptive and analytic epidemiology of restless legs syndrome (RLS) in the older Greek population, with a specific focus on lifestyle indicators.

METHODS

Baseline data from the randomly selected non-demented older participants of the population-based HELIAD cohort were analyzed. Multivariable binary logistic regression with RLS diagnosis as the dichotomous dependent outcome was performed. Demographic, socioeconomic, anthropometric, dietary, sleep-related and psychological parameters, physical activity, use of psychoactive substances and personal medical history were investigated for potential associations.

RESULTS

A total of 133 from the eligible sample of 1,838 participants were diagnosed with RLS. The mean age-sex standardized prevalence of RLS among the elderly was estimated at 6.1% (95%CI = 5.0-7.2), with a female (8.0%, 95%CI = 6.4-9.6) to male (3.7%, 95%CI = 2.4-5.1) ratio of 2.1. The prevalence of RLS peaked during the 8^th decade of life and diminished thereafter. The positive associations of RLS with female sex [OR = 2.06, 95%CI = (1.19-3.57)], anxiety levels [assessed by the 22-point HADS scale, OR = 1.08, 95%CI = (1.03-1.13)] and traumatic brain injury [OR = 2.22, 95%CI = (1.37-3.62)] were reproduced. Good sleep quality was related to 55% [95%CI~(24-83%)] lower odds of having RLS in comparison with both poor and moderate quality. Adherence to the Mediterranean dietary pattern [assessed by a 55-point scale, OR = 1.06, 95%CI = (1.01-1.11)], and low daily energy intake [low-moderate vs. low: OR = 0.45, 95%CI = (0.26-0.79)]; [moderate-high vs. low: OR = 0.69, 95%CI = (0.40-1.22)]; [high vs. low: OR = 0.31, 95%CI = (0.13-0.69)] were related to RLS for the first time.

CONCLUSIONS

More emphasis should be placed on the dietary-nutritional aspects of RLS.

Genome-wide analysis identified novel susceptible genes of restless legs syndrome in migraineurs

Background

Restless legs syndrome is a highly prevalent comorbidity of migraine; however, its genetic contributions remain unclear.

Objectives

To identify the genetic variants of restless legs syndrome in migraineurs and to investigate their potential pathogenic roles.

Methods

We conducted a two-stage genome-wide association study (GWAS) to identify susceptible genes for restless legs syndrome in 1,647 patients with migraine, including 264 with and 1,383 without restless legs syndrome, and also validated the association of lead variants in normal controls unaffected with restless legs syndrome (n = 1,053). We used morpholino translational knockdown (morphants), CRISPR/dCas9 transcriptional knockdown, transient CRISPR/Cas9 knockout (crispants) and gene rescue in one-cell stage embryos of zebrafish to study the function of the identified genes.

Results

We identified two novel susceptibility loci rs6021854 (in VSTM2L) and rs79823654 (in CCDC141) to be associated with restless legs syndrome in migraineurs, which remained significant when compared to normal controls. Two different morpholinos targeting vstm2l and ccdc141 in zebrafish demonstrated behavioural and cytochemical phenotypes relevant to restless legs syndrome, including hyperkinetic movements of pectoral fins and decreased number in dopaminergic amacrine cells. These phenotypes could be partially reversed with gene rescue, suggesting the specificity of translational knockdown. Transcriptional CRISPR/dCas9 knockdown and transient CRISPR/Cas9 knockout of vstm2l and ccdc141 replicated the findings observed in translationally knocked-down morphants.

Conclusions

Our GWAS and functional analysis suggest VSTM2L and CCDC141 are highly relevant to the pathogenesis of restless legs syndrome in migraineurs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-022-01409-9.

Restless legs syndrome affecting the head region: "restless head syndrome"

OBJECTIVE

Restless legs syndrome (RLS) is a well-established disease that has recently been shown to have variants affecting the arms, face, abdomen, and genital area. To our knowledge, there has been no study reporting on the RLS variant affecting the head region.

METHODS

The retrospective study reviewed a total of 460 patients who presented to Fırat University Medical School and were diagnosed as having RLS based on the International Restless Legs Syndrome Study Group (IRLSSG) criteria between June 2017 and January 2020. Of these, 18 patients that presented with head-related RLS symptoms (in addition to legs or arms) and four cases that presented with isolated head involvement were included in the study.

RESULTS

In 15 out of 18 (81.8%) patients, the restless head syndrome was accompanied by restless arm syndrome (RAS). In the remaining four (18.2%) patients, the disease involved the head region alone. The disease initially emerged in a single region in the body and gradually spread to one or multiple other regions in most patients and the symptoms were relieved by head rubbing. Serum iron level was low in 8 (36.4%) patients and normal in 14 (63.6%) patients. All the patients had normal cranial imaging and the symptoms were eliminated after dopaminergic therapy.

CONCLUSIONS

Although RLS typically involves the legs alone, it may also affect other body parts such as upper extremities, abdomen, face, and genital area. We propose that the novel RLS variant described in the present study could be termed "restless head syndrome."

Jidong Restless Legs Syndrome Cohort Study: Objectives, Design, and Baseline Screening

Background: Restless legs syndrome (RLS) is a common neurological disorder with unpleasant leg sensations and serious negative effects on mental and physical health. Many observational studies showed that people with RLS had a high risk of vascular diseases, including cerebrovascular and cardiovascular diseases (CVD), but the findings were conflicting. The Jidong RLS Cohort Study is a prospective cohort study designed to mainly examine whether or not RLS is associated with an increased risk of CVD. Methods and Design: The study recruited 8,867 healthy participants older than 18 years from October 2014 to December 2015. Participants received a physical examination in the Staff Hospital, Jidong Oilfield Branch, China National Petroleum Corporation. Baseline data and blood samples were collected. Restless legs syndrome was assessed using the international RLS diagnostic criteria. All of subjects would be followed up until December 2025. Major cardiovascular/cerebrovascular events including cardiac death, myocardial infarction, ischemic heart disease, heart failure, atrial fibrillation, ischemic, and hemorrhagic stroke will be the primary outcomes. Secondary outcomes include all-cause mortality, the decline in quality of life, cognitive impairment, and depression. Discussion: This study will contribute to the scientific evidence on the association between RLS and cardiovascular risks and also provide an unprecedented opportunity for early detection and prevention of CVD.

Restless Leg Syndrome Is Underdiagnosed in Hereditary Hemorrhagic Telangiectasia-Results of an Online Survey

BACKGROUND

Recurrent bleeding in patients with hereditary hemorrhagic telangiectasia (HHT) can lead to chronic iron deficiency anemia (CIDA). Existing research points to CIDA as a contributing factor in restless leg syndrome (RLS). The association between HHT-related symptoms and the prevalence of RLS was analyzed.

METHODS

An online survey was conducted whereby the standardized RLS-Diagnostic Index questionnaire (RLS-DI) was supplemented with 82 additional questions relating to HHT.

RESULTS

A total of 474 persons responded to the survey and completed responses for questions pertaining to RLS (mean age: 56 years, 68% females). Per RLS-DI criteria, 48 patients (48/322, 15%; 95% confidence interval (CI): 11-19%) self-identified as having RLS. An analysis of physician-diagnosed RLS and the RLS-DI revealed a relative frequency of RLS in HHT patients of 22% (95% CI: 18-27%). In fact, 8% (25/322; 95% CI: 5-11%) of the HHT patients had RLS which had not been diagnosed before. This equals 35% of the total amount of patients diagnosed with RLS (25/72; 95% CI: 25-46%). HHT patients with a history of gastrointestinal bleeding (prevalence ratio (PR) = 2.70, 95% CI: 1.53-4.77), blood transfusions (PR = 1.90, 95% CI: 1.27-2.86), or iron intake (PR = 2.05, 95% CI: 0.99-4.26) had an increased prevalence of RLS.

CONCLUSIONS

Our data suggest that RLS is underdiagnosed in HHT. In addition, physicians should assess CIDA parameters for possible iron supplementation.

[Restless legs syndrome]

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

(Neuro)Inflammatory Component May Be a Common Factor in Chronic Widespread Pain and Restless Legs Syndrome

Purpose of Review

Recent studies have linked fibromyalgia (nociplastic pain) and depression to neuroinflammation. Restless legs syndrome (RLS) is highly prevalent in CWP (chronic widespread pain) and FMS (fibromyalgia syndrome) as well as in depression. This review focuses on evidence in the relationship between CWP and RLS and possible common pathophysiological mechanisms.

Recent Findings

CWP is chronic pain spread over various locations of the body and is a cardinal sign of fibromyalgia. Poor sleep quality is a common symptom in fibromyalgia as well as high levels of fatigue, poor cognition, and other associated features which include depression, headache, and abdominal pain. Evidence for a bilateral relationship between pain and sleep deficit is robust. The latest research focus is not only on insomnia symptoms in chronic pain but also on other types of sleep disorders such as RLS which is characterized by complaints of an “urge to move” frequently associated with dysesthesias. These sensations can also have painful characteristics. Thus, there is a possible overlap between these two entities. The high prevalence of RLS (33–54%) in CWP has been shown in several studies. The pathophysiological mechanisms behind CWP and RLS are still not completely known, but there is a rising amount of evidence on proinflammatory and neuroinflammatory processes in CWP. In RLS, there are links to dopaminergic dysfunction and more generally to monoaminergic dysfunctional circuits, BID (brain iron deficiency), altered glutamatergic neurotransmission, and genetic traits. Depression is a common comorbidity as well in CWP as RLS, and proinflammatory mechanisms have also been demonstrated in this condition.

Summary

The association between CWP and RLS is shown to be high and the pathogenesis of both conditions is still not completely understood. Recent research is focusing on proinflammatory and neuroinflammatory processes, not uniquely emerging in fibromyalgia/CWP, but inflammatory features have been found in depression as well as in sleep deficit. Proinflammatory/neuroinflammatory processes may be an underlying, common factor in both CWP and RLS that future research should investigate further.

Inflammatory bowel disease and restless leg syndrome

Objectives:

Inflammatory bowel disease (IBD) has been associated with restless leg syndrome (RLS). This study aims to explore the prevalence, clinical predictors, and severity of RLS in IBD patients compared to controls.

Methods:

We conducted a case-control study between January and December of 2019 comparing IBD patients with controls. Assessment of RLS was performed using the previously validated diagnostic restless leg syndrome questionnaire (RLSQ). Logistic regression analyses were applied to investigate associations between patient demographics and clinical features and RLS diagnosis.

Results:

A total of 218 IBD patients and 211 healthy controls were incorporated after excluding 6 patients with positional discomfort and 4 patients with habitual foot tapping. The mean age was 30.2±11.7 and 64% were females. The prevalence of RLS was 16/218 (7.34%) and 17/211 (8.06%) among cases and controls, respectively. Based on the RLSQ severity score, 6/16 (37.5%), 4/16 (25%) and 1/16 (6.3%) of the IBD patients with RLS had mild, moderate and severe RLS; respectively. The odds of IBD were lower among patients with confirmed RLS (OR=0.90, 95% CI=0.44-1.84, p = 0.78). In the logistic regression analysis, only vitamin B12 deficiency (OR=10.20, 95% CI=1.40-74.10, p = 0.022) was associated with RLS diagnosis among IBD patients.

Conclusion:

No difference was found in the prevalence of RLS between IBD patients and non-IBD controls. Vitamin B12 deficiency was associated with RLS diagnosis among patients with IBD.

Different diagnostic criteria for periodic leg movements in patients with obstructive sleep apnea after continuous positive airway pressure titration

OBJECTIVE

Periodic leg movement in sleep (PLMS) is common among patients with obstructive sleep apnea (OSA). The PLMS frequency changes after continuous positive airway pressure (CPAP) titration. This study investigated the effects of two PLMS diagnostic criteria on PLMS prevalence and the restless leg syndrome (RLS) detection rate in patients with OSA before and after CPAP titration.

METHODS

This retrospective study included patients with OSA who received polysomnography (PSG) and successful CPAP titration from December 2012 to December 2014. Their clinical variables and sleep parameters were evaluated using the PLMS diagnostic criteria: PLMS index (PLMI) ≥5 and ≥15. PLMS prevalence and the RLS detection rate were analyzed according to the PLMI before and after CPAP.

RESULTS

In patients with OSA with a PLMI of ≥5 and ≥15 after PSG with CPAP titration, the PLMS prevalence was 20.1% (76/378) and 4.5% (17/378), respectively, which revealed CPAP titration increased PLMI. Moreover, in terms of PLMI ≥5 and ≥15, PSG with CPAP titration led to significantly higher PLMS prevalence than PSG alone (20.1% vs 7.1% and 4.5% vs 0.8%, respectively; both P<0.001). PLMI ≥5 also demonstrated a higher RLS detection rate than PLMI ≥15 did (69.2% vs 15.4%; P=0.016).

CONCLUSION

In patients with OSA, CPAP titration increases PLMS prevalence and the PLMI regardless of whether PLMI is ≥5 or ≥15. The use of the current diagnostic criteria, PLMI ≥15, for PLMS may lead to underestimation of PLMS prevalence and the RLS detection rate in patients with OSA.

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.

Comparative efficacy and acceptability of treatments for restless legs syndrome in end-stage renal disease: a systematic review and network meta-analysis

Background

Restless legs syndrome (RLS) is common in end-stage renal disease (ESRD) patients and impairs health and quality of life significantly. However, the optimal treatment of RLS in ESRD patients is uncertain and less studied compared with idiopathic RLS patients.

Methods

We conducted a systematic review and network meta-analysis to compare the efficacy and acceptability of treatments for RLS in ESRD patients. Randomized controlled trials (RCTs) by February 2019 in the PubMed, Cochrane Library, Embase and ClinicalTrials.gov were reviewed. RLS severity reduction was treated as treatment efficacy, and adverse events were treated as acceptable. Both outcomes were appraised using a random effects model expressed as standardized mean differences and odds ratios with 95% confidence intervals (CIs), respectively, and were ranked using surface under the cumulative ranking curve (SUCRA) probabilities to obtain a hierarchy of interventions.

Results

A total of 12 RCTs were included, comprising 9 interventions and 498 participants. All the interventions significantly improved RLS severity without critical side effects compared with placebo. Gabapentin achieved the greatest decrease of RLS severity [standardized mean difference (SMD) = 1.95, 95% CI 0.81–3.09 (SUCRA: 79.3%)], despite its frequent adverse events [SMD = 0.18, 95% CI 0.02–1.50 (19.9%)]. The combination therapy of exercise plus dopamine agonist had better efficacy [SMD = 1.60, 95% CI 0.08–3.12 (59.8%)] and acceptability [SMD = 1.41, 95% CI 0.01–142.53 (63.9%)] compared with that of vitamin C plus vitamin E [SMD = 1.50, 95% CI 0.47–2.54 (56.6%); SMD = 0.32, 95% CI 0.04–2.86 (32.5%)].

Conclusions

This network meta-analysis supports that gabapentin is the most effective treatment for RLS in ESRD patients. Exercise plus dopamine agonist is a favorable combination therapy concerning side effects. Future large RCTs with long-term treatment outcomes are necessary.

Association between Restless Legs Syndrome Symptoms and Self-Reported Hypertension: a Nationwide Questionnaire Study in Korea

BACKGROUND

The association between restless legs syndrome (RLS) and hypertension remains controversial. We investigated the relationship between RLS and hypertension in a nationwide sample of the Korean adult population.

METHODS

This was a cross-sectional questionnaire-based study including 2,740 adults aged 19 years or more. Subjects who met the four essential International RLS Study Group criteria and reported symptoms occurring at least once a week were defined as the RLS group. The presence of hypertension was defined as a self-reported history of physician-diagnosed hypertension. We conducted multiple logistic regression analysis to determine the independent association between RLS symptoms and self-reported hypertension after adjusting for potential confounding factors.

RESULTS

Among the 2,740 subjects, 68 (2.5%; 95% confidence interval [CI], 1.9%-3.1%) were found to have RLS with a symptom frequency of at least once a week. The prevalence of self-reported hypertension was 30.9% (95% CI, 20.5%-42.0%) in the RLS group, which was significantly higher than that in controls (12.4%; 95% CI, 11.2%-13.6%; P < 0.001). Multiple logistic regression analysis showed that the adjusted odds ratio for self-reported hypertension in the RLS group was 2.10 (95% CI, 1.12-3.93) compared to controls. In addition to RLS symptoms, old age, being overweight, low education level, diabetes mellitus, and short sleep duration were significantly associated with self-reported hypertension.

CONCLUSION

RLS symptoms occurring at least once a week is independently associated with a higher prevalence of self-reported hypertension in the adult Korean population. Further research will confirm the clinical implication of the present results and the causal relationship between RLS and hypertension.

Depression is differently associated with sleep measurement in obstructive sleep apnea, restless leg syndrome and periodic limb movement disorder

Depression causes sleep disturbance and is associated with various sleep-related disorders. However, how depression affects the symptomatic presentation of different sleep-related disorders is unclear. In this study, we investigated the sleep parameters of different sleep-related disorders between depressive and non-depressive patients. A total of 785 patients underwent polysomnography in a mental hospital from Jan 2012 to Jun 2013. We first analyzed variables between the depressive and non-depressive groups. The patients were then divided into four groups: obstructive sleep apnea (OSA, n = 339), restless leg syndrome (RLS, n = 51), periodic limb movement disorder (PLMD, n = 58) and comorbid group (OSA and RLS, n = 46). We next compared sleep measures between the depressive and non-depressive subjects within each groups. The patients with OSA and depression were significantly associated with a higher periodic limb movement index. Significantly more patients with RLS patients and depression had initial insomnia complaints. However, significantly more patients with PLMD and depression middle insomnia. Compared with non-depressive population, depressive patients had higher comorbidity with RLS and PLMD. Depression may have different association with the sleep parameters in different sleep-related disorders. Further investigations are needed to investigate how these findings may affect patients' awareness and clinicians' diagnosis and management of sleep-related disorders.

Restless Legs Syndrome and Other Movement Disorders of Sleep-Treatment Update

PURPOSE OF REVIEW

The purpose of this review article is to summarize and discuss the recent advances in the treatment of restless legs syndrome (RLS), as well as REM sleep behavior disorder (RBD), and periodic leg movement disorder (PLMD).

RECENT FINDINGS

Traditionally, dopaminergic therapy has been considered the sole option for first-line treatment of RLS due to their impressive acute efficacy. Dopamine agonists such as oral pramipexole and ropinirole, as well as transdermal rotigotine are all effective treatment options. However, augmentation of the RLS symptoms is a major limitation of oral dopaminergic therapy. Recently, gabapentinoid agents such as gabapentin enacarbil and pregabalin have shown comparable short-term efficacy to dopaminergics with lower risk of augmentation of the RLS symptoms. Recent evidence on the efficacy of oxycodone-naloxone in treatment-resistant RLS provides an additional therapeutic avenue. The increasing understanding of the role of iron in RLS pathophysiology has led to new options in iron supplementation therapy in RLS, including treatment with ferric carboxymaltose. With emerging evidence of augmentation being a side effect specific to dopaminergic treatment, gabapentinoids are considered a safer option as initial treatment. In severe refractory RLS, oxycodone-naloxone can be used. If iron stores are low, IV iron formulations should be the initial treatment choice. New treatment options are needed to address issues with current therapies.

Higher Prevalence of Hypertension among Individuals with Restless Legs Syndrome: A Meta-Analysis

OBJECTIVE

This study investigated the proposed association between restless legs syndrome (RLS) and the prevalence of hypertension.

METHODS

A meta-analysis was conducted based on searches of the PUBMED, EMBASE, Cochrane Library, and Korean electronic databases. Cohort and cross-sectional studies reporting the incidence of hypertension in individuals with RLS were included. Dichotomous data were pooled to obtain an odds ratio (OR) and 95% confidence interval (CI) for the prevalence of hypertension in individuals with RLS. The main outcome measure of the study was prevalence of hypertension in patients with RLS compared with a control group.

RESULTS

One cohort study and eight cross-sectional studies were included in the meta-analysis. Individuals with RLS had an increased prevalence of hypertension (all studies: OR=1.13, 95% CI=1.04-1.23; cross-sectional studies: OR=1.12, 95% CI=1.01-1.24). However, in subgroup analyses controlling for cardiovascular risk factors, such as diabetes mellitus and dyslipidemia, the differences in the prevalence of hypertension between RLS and control patients were no longer significant.

CONCLUSION

Patients with RLS may have a higher prevalence of hypertension, according to a pooled analysis, but the results remain to be confirmed in well-designed prospective studies.

Risk factors of primary and secondary restless legs syndrome among a middle-aged population in Saudi Arabia: A community-based study

INTRODUCTION:

Restless legs syndrome (RLS) is etiologically divided into primary and secondary syndromes. However, a comparative description of both types is lacking in the literature. We compared primary and secondary RLS with respect to demographic determinants, associated risk factors, and comorbidities.

METHODS:

Following a cross-sectional survey on the prevalence of RLS in a Saudi population, RLS cases were identified using the International RLS Study Group (IRLSSG) criteria. Cases were assessed with an interview-based questionnaire regarding baseline characteristics, risk factors, and comorbidities and with lower limb examinations and laboratory measurements. RLS severity was assessed using the IRLSSG Severity Rating Scale.

RESULTS:

In total, 78 patients with RLS, including 50 (64.1%) primary and 28 (35.9%) secondary cases, were examined. Of the primary cases, 35 (70%) were male; of the secondary cases, 25 (89.3%) were female (P < 0.001). Multivariate regression confirmed the association of male gender with primary RLS (odds ratio = 14.53, 95% confidence interval [2.9–75], P = 0.001). There were more dark- and black-skinned participants in the primary RLS group (38, 72%) than in the secondary group (15, 28%) (P = 0.042). Iron deficiency was observed in most (26, 92%) of the secondary cases. More severe symptoms were reported in secondary than in primary RLS cases (P < 0.05).

CONCLUSIONS:

Primary RLS is more common but less severe than secondary RLS. Male gender and ethnicity play significant roles in primary RLS, whereas female gender and iron deficiency may be the main risk factors associated with secondary RLS.

Association of BTBD9 and MAP2K5/SKOR1 With Restless Legs Syndrome in Chinese Population

Study Objectives

The aim of the study was to investigate the relationship between genetic factors and primary restless legs syndrome (RLS) in Chinese population.

Methods

A total of 116 RLS patients and 200 controls were recruited and the diagnosis of RLS was based on the criteria of International RLS Study Group. Polymer chain reaction (PCR) and sequencing were used to detect 19 single nucleotide polymorphisms (SNPs) in six genetic loci (MEIS1, BTBD9, PTPRD, MAP2K5/SKOR1, TOX3, and Intergenic region of 2p14).

Results

Our study found that one SNP increased the risk of RLS in Chinese population: rs6494696 of MAP2K5/SKOR1 (odds ratio [OR] = 0.09, p < .0001, recessive model). A further meta-analysis of RLS in Asian population found that two SNPs of BTBD9 increased the risk of RLS: rs9296249 of BTBD9 (OR = 1.44, p = .000, T allele), rs9357271 of BTBD9 (OR = 1.38, p = .021, dominant model).

Conclusion

Our results confirmed the association of BTBD9 and MAP2K5/SKOR1 with primary RLS in Chinese population.

Restless Legs Syndrome: From Pathophysiology to Clinical Diagnosis and Management

Restless legs syndrome (RLS), a common neurological sensorimotor disorder in western countries, has gained more and more attention in Asian countries. The prevalence of RLS is higher in older people and females. RLS is most commonly related to iron deficiency, pregnancy and uremia. The RLS symptoms show a significant circadian rhythm and a close relationship to periodic limb movements (PLMs) in clinical observations, while the pathophysiological pathways are still unknown. The diagnostic criteria have been revised in 2012 to improve the validity of RLS diagnosis. Recent studies have suggested an important role of iron decrease of brain in RLS pathophysiology. Dopaminergic (DA) system dysfunction in A11 cell groups has been recognized long ago from clinical treatment and autopsy. Nowadays, it is believed that iron dysfunction can affect DA system from different pathways and opioids have a protective effect on DA system. Several susceptible single nucleotide polymorphisms such as BTBD9 and MEIS1, which are thought to be involved in embryonic neuronal development, have been reported to be associated with RLS. Several pharmacological and non-pharmacological treatment are discussed in this review. First-line treatments of RLS include DA agents and α2δ agonists. Augmentation is very common in long-term treatment of RLS which makes prevention and management of augmentation very important for RLS patients. A combination of different types of medication is effective in preventing and treating augmentation. The knowledge on RLS is still limited, the pathophysiology and better management of RLS remain to be discovered.

The gender difference of snore distribution and increased tendency to snore in women with menopausal syndrome: a general population study

Purpose

Sleep-disordered breathing (SDB) is a prevalent disorder with a major impact in women, especially postmenopausal women. However, few studies have investigated the prevalence of a specific SDB, snoring, among women especially those with menopausal syndrome.

Methods

Computer-assisted telephone interviews were conducted in Taiwan. Adults over 20 years of age were interviewed. The number of successful interviews was calculated based on the population prior to the study. Demographic data and information about snoring, menopausal syndrome, and medical conditions were obtained.

Results

In total, 3624 adults, 1473 males and 2151 females, completed the interviews. Both men and women shows an increase in snoring until age 50 to 59 years, followed by a decline in snoring that is less steep among women. The prevalence of snoring increased significantly in females after age 50 years, which is the mean menopausal age in our country (p < 0.05). After adjusting for age, body mass index, and other major diseases, the percentage of women with snoring was significantly higher among those with menopausal syndrome than those without menopausal syndrome (p = 0.021, odds ratio = 1.629).

Conclusions

This population-based study revealed different snoring percentages among men and women and diminishing differences in the older population. Additionally, the percentage of women with snoring was increased among those women who were older than 50 years and those with menopausal syndrome.

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%).

Restless legs syndrome associated with major diseases: A systematic review and new concept

Recent publications on both the genetics and environmental factors of restless legs syndrome (RLS) defined as a clinical disorder suggest that overlapping genetic risk factors may play a role in primary (idiopathic) and secondary (symptomatic) RLS. Following a systematic literature search of RLS associated with comorbidities, we identified an increased prevalence of RLS only in iron deficiency and kidney disease. In cardiovascular disease, arterial hypertension, diabetes, migraine, and Parkinson disease, the methodology of studies was poor, but an association might be possible. There is insufficient evidence for conditions such as anemia (without iron deficiency), chronic obstructive pulmonary disease, multiple sclerosis, headache, stroke, narcolepsy, and ataxias. Based on possible gene-microenvironmental interaction, the classifications primary and secondary RLS may suggest an inappropriate causal relation. We recognize that in some conditions, treatment of the underlying disease should be achieved as far as possible to reduce or eliminate RLS symptoms. RLS might be seen as a continuous spectrum with a major genetic contribution at one end and a major environmental or comorbid disease contribution at the other.

Sleep medicine in Taiwan

The sleep medicine is a young medical science in Taiwan. It began from less than 10 sleep beds 20 years ago in four hospitals all over Taiwan. By the organization of sleep team in Chang Gung Memorial Hospital and the initiation of Taiwan Society of Sleep Medicine, sleep medicine becomes a popular medicine in the past decades. The setting of Sleep Society in 2002 is the milestone to promote the sleep medicine, educate the public and professionals, and control of the quality of clinical practice. Epidemiologic study in Taiwan shows many Taiwanese suffer from sleep disorders and hence more sleep institutes are needed. Accreditation has become a mission of the Taiwan Society of Sleep Medicine. Technicians, sleep centers, sleep specialists and sleep phycologists are gradually certified by the society. 215 sleep technicians, 307 sleep physicians, 31 iCBT therapists and 21 sleep centers are certified by the society till 2015. The first sleep related medical courses are initiated in the Department of Respiratory Therapy in Chang Gung University from 2003. For the following years, eight medical courses are set in six Universities now. Given the fact that the Asian accounts for the largest proportion of population in the world, investigation on the OSA in Asian population is essential. In this article, we aimed to demonstrate the outcomes of OSA-related research in Asia. In particular, the progress driven by the studies in Taiwan will be discussed. Data were obtained online from the Science Citation Index Expanded database of the Thomson Reuters' Web of Science Core Collection. Keywords including "apnea" and "hyponea" were used to search by applying the filters of the title and the publication years between 1991 and 2014. In total, 2623 articles were hit, subject to the criteria for data search. Among the 2623 articles, sleep and breathing related articles (128, 4.95 %) were the most frequently reported. Japan is the country that published the highest amount of OSA-related articles. The Asian institutions that ranked the first two in the number of OSA-related articles were Technion-Israel Institute of Technology and Tel Aviv University in Israel. In Taiwan, Chang Gung Memorial Hospital and Chang Gung University ranked fourth and fifth. Both institutes reported 63 articles. In Asia, Japan leads in the quantity of publication and the Japanese research institutes performed evenly. China had rapid growth in the number of articles since 2011. Although sleep medicine developed smoothly in the past decades in Taiwan, there were problems that the sleep society and specialists had to encounter. Insurance limits the expansion of sleep labs and the reimbursement is very low for sleep medicine to survive. The affiliations of sleep specialist and the sleep education are also important issue that the sleep specialists in the society have to discuss.The previous achievements do not guarantee future success. We have to face these problems seriously and take action for the following years to maintain the development of sleep medicine in Taiwan.

Risk of Restless Legs Syndrome Following Tension-Type Headache: A Nationwide Population-Based Cohort Study

Migraine and restless legs syndrome (RLS) appear to be associated, but the relationship between tension-type headache (TTH) and RLS is unknown. This nationwide, population-based, retrospective cohort study explored the potential association between TTH and RLS.We identified 15,504 patients with newly diagnosed TTH from 2000 to 2007 and 62,016 individuals without TTH who were selected by frequency matched based on sex, age, and the index year. The study participants were followed until diagnosed with RLS, withdrawal from the NHI program, or the end of 2011. Cox proportional hazard models were used to identify risk factors for RLS in TTH patients.After adjusting for sex, age, comorbidity, and medications, TTH was significantly associated with an increased risk of RLS (hazard ratio [HR] = 1.57, 95% confidence interval [CI] = 1.22-2.02). The risk was most prominent in patients aged 20 to 39 years in the TTH group, which exhibited a 2.60-fold higher risk (95% confidence interval = 1.53-4.42) of RLS compared with the non-TTH group. The TTH group had a higher risk of RLS than that of the non-TTH group regardless of sex.Tension-type headache appears to be associated with an increased risk of developing RLS. This similarity to migraines may indicate that headache and RLS have a coincident pathophysiological mechanism, a possibility requiring further study. Clinicians should be more attentive to RLS as a possible comorbidity in patients with TTH.

Comparison of impact of insomnia on depression and quality of life in restless legs syndrome/Willis-Ekbom disease and primary insomnia patients

BACKGROUND

Although insomnia is common among people with restless legs syndrome (RLS), its impact on the daily suffering of those with RLS remains unclear. This study aimed to compare the differential impact of clinical insomnia on depression and quality of life (QoL) among people with RLS, primary insomnia, and healthy controls.

METHODS

A total of 148 people with RLS, 115 with primary insomnia, and 117 healthy controls were enrolled into this cross-sectional study. Participants completed sleep, depression, and QoL questionnaires. Clinical insomnia was defined as Korean version of the Insomnia Severity Index (K-ISI) ≥ 15. Correlation coefficients between sleep measures and both depression and QoL were calculated. Multivariate regression was used to identify the clinical factors that were most closely associated with depression and QoL among people with RLS and primary insomnia.

RESULTS

Participants with RLS had insomnia and sleep quality at intermediate levels between the healthy controls and primary insomnia subjects, but those with clinical insomnia had equivalent depression and QoL scores regardless of RLS diagnosis. Insomnia severity correlated with depression and QoL in RLS and primary insomnia. Multivariate regression, however, revealed that RLS severity was the most overall predictive factor for depression and QoL among those with RLS. Insomnia severity was the strongest predictor in primary insomnia.

CONCLUSION

Insomnia was more closely associated with depression and QoL among people with primary insomnia than those with RLS, but clinical insomnia may have a significant impact in RLS as well. Future RLS studies should account for sleep quality in addition to RLS symptom severity when investigating mood and QoL.

Restless Leg Syndrome Across the Globe: Epidemiology of the Restless Legs Syndrome/Willis-Ekbom Disease

There are more than 50 epidemiologic studies measuring the prevalence of restless legs syndrome/Willis-Ekbom disease (RLS/WED) across 5 of the 6 inhabited continents (not Australia), most conducted in North America and Europe. Sufficient studies have been conducted in Asia, North America, and Europe to make inferences on RLS/WED prevalence by region. RLS/WED prevalence is thought to be highest in North America and Europe and lower in Asia. These differences across regions may be explained by cultural, environmental, and genetic factors. Future investigation is needed to determine to what extent these factors affect expression of RLS/WED according to world region.

Prevalence and risk factors of restless legs syndrome among Chinese adults in a rural community of Shanghai in China

Aims

The primary objective of this study was to investigate the prevalence and risk factors of restless legs syndrome (RLS) in an adult Chinese population living in a rural community. We also aimed to determine the predictive diagnostic value of the 4-item screening questionnaire for RLS in this population.

Methods

This study was designed as a 2-phase survey. In phase 1 we performed a face-to-face interview of eligible individuals living in a rural community in Shanghai using a 4-item screening questionnaire. In phase 2, sleep specialists performed a phone interview of the individuals who screened positive to diagnosis RLS.

Results

Forty-one RLS cases were confirmed among 2941 eligible individuals 18 years of age or older in the study community. The prevalence of RLS was 1.4% (95% confidence interval (CI) =1.0-1.9%), with a significantly higher rate observed in females (1.9% [95%CI =1.3-2.7%]) than that in males (0.9% [95%CI =0.5-1.5%], p=0.019). The prevalence rate increased significantly with age, from 0.2% (95% CI =0.08-0.6%) in those 18-39 years old to 4.1% (95% CI =2.1-7.9%) in those ≥70 years old (p<0.001). The multivariate logistic regression analysis indicated that gastritis, anemia and hypertension were risk factors for RLS. The sensitivity and specificity of the 4-item screening questionnaire used in this study were 63.4% and 97.5%, respectively.

Conclusion

RLS prevalence is relatively low among Chinese adults living in rural Shanghai. Furthermore, population-based studies with a larger sample size and a longitudinal follow-up may help to determine the risk factors of RLS and potential interventions for RLS.

An update on restless legs syndrome (Willis-Ekbom disease): clinical features, pathogenesis and treatment

PURPOSE OF REVIEW

In recent years, there have been a number of advances in the field of restless legs syndrome (RLS) or Willis-Ekbom disease (WED). Here, we review recent studies pertaining to the diagnosis and clinical features, pathogenesis, and treatment of RLS/WED.

RECENT FINDINGS

Recent studies have added a temporal dimension to RLS/WED epidemiology by examining both the incidence and persistence rates in different populations. Diagnostic criteria have been modified to increase sensitivity, and new guidelines take into account recently published studies of different drug classes.

SUMMARY

Recent epidemiological findings have shown that RLS/WED is a common neurological disorder that affects up to 5% of the adult population in Western countries. In moderate and severe cases, RLS/WED has a strong impact on sleep and quality of life and can involve an increased cardiovascular risk. Diagnosis is made clinically by confirming the presence of the five essential criteria. However, in difficult cases objective tests such as the multiple suggested immobilization test (m-SIT) can be used. The pathophysiology is partially known, with several risk polymorphisms (BTBD-9 (BTB (POZ) domain containing 9), MEIS-1 (Meis homeobox 1), protein tyrosine phosphatase, receptor type, D, and others) playing an important role, along with dopaminergic and iron dysfunctions. The disorder frequently requires long-term treatment with low-dose dopamine agonists or α2δ ligands. Dopamine agonists are usually effective but the main complication, RLS/WED augmentation, can arise.

Restless legs syndrome and hypertension in Chinese pregnant women

Hypertension is a common complication of pregnancy, and studies show that pregnant women are more likely to suffer from restless legs syndrome (RLS). Pregnant women with hypertension and RLS often experience disrupted sleep patterns because of activation of the nervous system. The present study aimed to clarify the relationship between hypertension and RLS in pregnant women, and their impact on sleep. We enrolled 3,781 pregnant women who were admitted at our hospital for delivery between May 2011 and May 2014. The face-to-face questionnaire used to gather data included the International RLS Study Group criteria for diagnosis, Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and hypertension diagnosis. Depending on the time of occurrence of hypertension, it was divided into two different types: pregnancy-induced hypertension and chronic hypertension in pregnancy. Out of 3,781 patients, 453 fulfilled the diagnostic criteria for RLS and 486 met the diagnostic criteria for hypertension. Among patients with RLS, prophylactic iron supplementation was less frequently taken during pregnancy. Pregnancy-induced hypertension, rather than chronic hypertension in pregnancy, was found to be more frequent in patients with RLS; pregnant women with RLS had higher PSQI and ESS scores than pregnant controls. In our study, RLS was frequent in pregnant women, especially in those without prophylactic iron supplementation. Patients with RLS described more serious sleep disruption and excessive daytime sleepiness (EDS). In addition, pregnancy-induced hypertension was more common in patients with RLS.

Prospective study of obesity, hypertension, high cholesterol, and risk of restless legs syndrome

Because previous cross-sectional studies suggest an association between metabolic disorders and restless legs syndrome (RLS), we prospectively evaluated whether obesity, hypercholesterolemia, and hypertension were associated with increased risk of RLS. Our study consisted of 42,728 female participants from the Nurses' Health Study II and 12,812 male participants from the Health Professionals Follow-up Study, free of RLS at baseline (2002 for men and 2005 for women), and free of diabetes and arthritis through follow-up (2002-2008 for men and 2005-2009 for women). RLS symptoms were assessed using the International RLS Study Group's standardized questionnaire. We considered RLS symptoms a "case" if the symptoms occurred ≥5 times/month and met International RLS Study Group criteria. We found that obesity was associated with an increased risk RLS among both men and women (P difference for sex >0.5). The pooled multivariate-adjusted odds ratio (OR) for RLS was 1.57 (95% confidence interval [CI]: 1.33-1.85; P trend <0.0001) for body mass index >30 versus ≤23 kg/m(2) and 1.56 (95% CI: 1.29-1.89; P trend = 0.0001) comparing two extreme waist circumference quintiles, adjusting for age, ethnicity, smoking, physical activity, use of antidepressant, and other covariates. A similar significant association was found for high cholesterol; the pooled adjusted OR for total serum cholesterol >240 versus <159 mg/dL was 1.33 (95% CI: 1.11-1.60; P trend = 0.002). There was no significant association between hypertension and RLS risk (adjusted OR: 0.90; 95% CI: 0.79-1.02). In this large, prospective study, we found that obesity and high cholesterol, but not high blood pressure, were significantly associated with an increased risk of developing RLS. © 2014 International Parkinson and Movement Disorder Society.

Restless legs syndrome and pregnancy: a review

Restless legs syndrome (RLS) is a common sensorimotor neurological disorder that is diagnosed according to the revised criteria of the International RLS Study Group (IRLSSG). The pathophysiology of RLS is still unknown and its prevalence is influenced by ethnicity, age, and gender. RLS is divided into two types by etiology: primary or idiopathic and secondary. Primary RLS is strongly influenced by a genetic component while secondary RLS is caused by other associated conditions such as end-stage renal disease or peripheral neuropathy. Another common condition associated with RLS is pregnancy. The prevalence of RLS during pregnancy is two to three times higher than in the normal population and is influenced by the trimester and the number of parity. The main mechanisms that may contribute to the pathophysiology of RLS during pregnancy are hormonal changes and iron and folate status. Standard medications for treating RLS during pregnancy are not established. Most medications have been used according to the evidence from non-pregnant patients. Therefore, consideration of the medical treatment for treating RLS during pregnancy should be balanced between the benefit of relieving the symptoms and maternal and fetal risk. In general, the prognosis of RLS during pregnancy is good and symptoms are usually relieved after delivery.

Restless legs symptoms in adolescents: epidemiology, heritability, and pubertal effects

AIMS

We aimed to determine the prevalence, pubertal effect, familial aggregation, and heritability of restless legs (RLS) symptoms in Chinese adolescents. In addition, the correlates and consequences of RLS symptoms were examined.

METHODS

This was a population-based family study that involved 1549 adolescents (probands), their parents and siblings. RLS symptoms were assessed by a single question measuring the core features of RLS. Subjects with RLS symptoms for at least once per week were considered as abnormal. Impairment of daytime functions, behavioral problems, health status, and lifestyle practice were also documented.

RESULTS

The prevalence of RLS symptoms was 2.8% in adolescents and 7.4% in their parents with female preponderance. Gender difference of RLS symptoms emerged in mid-pubertal adolescents (Tanner stage 3 or above). RLS symptoms were closely associated with various sleep problems (range of ORs=2.24 to 32.5, p<0.05), except habitual snoring. They were also independently associated with impairment of daytime functions, poor general health and frequent temper outbursts but not caffeine or alcohol intake or cigarette smoking after adjustment for age, sex, and other comorbid sleep problems. RLS symptoms presented with a modest familial aggregation and heritability (h²±SE=0.17±0.04, p<0.001).

INTERPRETATION

RLS symptoms are common in Chinese adolescents with significant health repercussions. Puberty plays a critical role in the emergence of gender difference of RLS symptoms, which are accounted for by both genetic and environmental factors.

Development and Validation of Sleep Disturbance Questionnaire in Patients with Acute Coronary Syndrome

Background and Objectives. Severe sleep disturbance is a common problem among patients in cardiac care units (CCUs). There are questionnaires to measure sleep disturbances. Therefore, the present study seeks to design a valid and reliable questionnaire to assess sleep disturbance in patients with acute coronary syndrome (ACS) hospitalized in CCUs. Materials and Methods. In the present methodological research, items of the questionnaire were extracted through a systematic review. The validity and reliability of the questionnaires was assessed by face validity, content validity, construct validity, Cronbach's alpha coefficient, and test-retest methods. Results. Factor analysis provided a questionnaire of 23 items on 5 dimensions of sleep disturbance in coronary patients: “sleep onset and continuity disorder,” “disorder in daytime functioning,” “sleep disturbance caused by environmental factors,” “sleep disturbance as a result of cardiac diseases,” and “respiratory disorders during sleep.” Furthermore, test-retest analysis showed a reliability correlation coefficient of r = 0.766 and α Cronbach's reliability (α = 0.855). Conclusion. Sleep disturbance questionnaire for patients with ACS hospitalized in coronary care unit (CCU) was identified in 5 dimensions and assessed for validity and reliability. To control and improve the sleep quality of CCU hospitalized patients, we need to identify and remove predisposing factors.

Diseases in patients coming to a sleep center with symptoms related to restless legs syndrome

Study Objective

To explore the profile of patients who visit a sleep center with symptoms that fulfill the four essential criteria for restless legs syndrome (RLS).

Design

A prospective study.

Setting

Outpatients from one sleep disorders clinic in Taiwan.

Participants

1,200 consecutive patients visit sleep disorders clinic with any sleep complaints.

Interventions

After completing a history and physical examination, all participants answered the RLS questionnaire. Subjects who fulfilled the four essential criteria for RLS were referred to a special clinic. A work-up including blood tests, polysomnography, and specialized neurological tests etc. was performed to make the final diagnosis.

Measurements and Results

A total of 1,185 participants were enrolled, and, of these, 131(11.1%) fulfilled the four essential criteria for RLS, and 121 completed the supplemental work-up. Their mean age was 47.6±13.3 and 52.9% were male. Insomnia and snoring were the most common chief complaints. Obstructive sleep apnea syndrome and other diseases were found in 103 patients. Only 18 (14.9%) patients had no comorbid condition and were diagnosed with primary RLS.

Conclusions

Symptoms of RLS are common in patients with sleep complaints. Even in a sleep clinic, using a questionnaire approach for identification of RLS has a low positive predictive value. Clinicians should pay attention to the limitations of the 4-item questionnaire in diagnosis of RLS and also the importance of a careful differential diagnosis to identify possible secondary causes of RLS.

Restless legs syndrome as a comorbidity in rheumatoid arthritis

Rheumatoid arthritis (RA) is a multisystem disease with a complex immunologic pathophysiology. Likewise, sleep disorders can involve a complicated interplay between the neurologic pathways, immune system, and respiratory system. Recent studies have shown an elevated prevalence of sleep abnormalities in connective tissue disorders compared to the general population. Restless legs syndrome (RLS) may be present in up to 30% of RA patients. These findings may be related to cytokine release and other immunomodulatory responses. TNF- α levels relate to sleep physiology and anti-TNF- α therapy may improve sleep patterns. Most of the patients with this disorder can distinguish their RLS sensations from their arthritic symptoms. RLS is a common comorbidity seen with RA, and prompt recognition and treatment can improve patient quality of life.

Vascular risk factors, cardiovascular disease, and restless legs syndrome in women

BACKGROUND

Previous studies evaluating the association of cardiovascular disease and vascular risk factors with restless legs syndrome showed inconsistent results, especially for the potential relation between various vascular risk factors and restless legs syndrome. We therefore aimed to analyze the relationships between vascular risk factors, prevalent cardiovascular disease, and restless legs syndrome.

METHODS

This is a cross-sectional study of 30,262 female health professionals participating in the Women's Health Study (WHS). Restless legs syndrome was defined according to diagnostic criteria of the International Restless Legs Study Group. Information on vascular risk factors (diabetes, hypertension, hypercholesterolemia, body mass index [BMI], alcohol, smoking, exercise, and family history of myocardial infarction) was self-reported. Cardiovascular disease events (coronary revascularization, myocardial infarction, and stroke) were confirmed by medical record review. Prevalent major cardiovascular disease was defined as nonfatal stroke or nonfatal myocardial infarction. Logistic regression models were used to evaluate the association between vascular risk factors, prevalent cardiovascular disease, and restless legs syndrome.

RESULTS

Of the 30,262 participants (mean age: 63.6 years), 3624 (12.0%) reported restless legs syndrome. In multivariable-adjusted models, BMI (odds ratio [OR] for BMI ≥35 kg/m(2), 1.35; 95% confidence interval [CI], 1.17-1.56), diabetes (OR, 1.19; 95% CI, 1.04-1.35), hypercholesterolemia (OR, 1.17; 95% CI, 1.09-1.26), smoking status (OR for ≥15 cigarettes/day, 1.41; 95% CI, 1.19-1.66), and exercise (OR for exercise ≥4 times/week, 0.84; 95% CI, 0.74-0.95) were associated with restless legs syndrome prevalence. We found no association between prevalent cardiovascular disease (major cardiovascular disease, myocardial infarction, and stroke) and restless legs syndrome prevalence. Women who underwent coronary revascularization had a multivariable-adjusted OR of 1.39 (1.10-1.77) for restless legs syndrome.

CONCLUSIONS

In this large cohort of female health professionals, various vascular risk factors are associated with the prevalence of restless legs syndrome. We could not confirm the results of previous reports indicating an association between prevalent cardiovascular disease and restless legs syndrome.