Comorbidity in restless legs syndrome among a sample of Swedish adults

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.

Restless legs syndrome: Over 50 years of European contribution

Restless legs syndrome (RLS) is a sensorimotor neurological disorder characterised by an urge to move the limbs with a circadian pattern (occurring in the evening/at night), more prominent at rest, and relieved with movements. RLS is one of the most prevalent sleep disorders, occurring in 5%-10% of the European population. Thomas Willis first described RLS clinical cases already in the 17th century, and Karl-Axel Ekbom described the disease as a modern clinical entity in the 20th century. Despite variable severity, RLS can markedly affect sleep (partly through the presence of periodic leg movements) and quality of life, with a relevant socio-economic impact. Thus, its recognition and treatment are essential. However, screening methods present limitations and should be improved. Moreover, available RLS treatment options albeit providing sustained relief to many patients are limited in number. Additionally, the development of augmentation with dopamine agonists represents a major treatment problem. A better understanding of RLS pathomechanisms can bring to light novel treatment possibilities. With emerging new avenues of research in pharmacology, imaging, genetics, and animal models of RLS, this is an interesting and constantly growing field of research. This review will update the reader on the current state of RLS clinical practice and research, with a special focus on the contribution of European researchers.

Restless Leg Syndrome in Hemodialysis Patients: A Narrative Review

BACKGROUND

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

REVIEW SUMMARY

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

CONCLUSION

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

Prevalence of pica and rumination behaviours in adults and associations with eating disorder and general psychopathology: findings form a population-based study

AIMS

Pica and rumination disorder are known as feeding disorder diagnoses in childhood, but little is known about their occurrence in adulthood. This study aimed to assess prevalence rates of one-time and recurrent pica and rumination behaviours (PB and RB) in adults, including sociodemographic subgroups, and to examine associations with other eating disorder and general psychopathology.

METHODS

The representative population sample (N = 2403) completed measures on PB and RB, symptoms of avoidant/restrictive food intake disorder (ARFID), body image and symptoms of depression and anxiety.

RESULTS

Any PB and RB were reported in 5.33 and 5.49%, respectively, while recurrent PB or RB occurred in 1.08 and 0.71%, respectively. Co-occurrence was high, with 35.29% of recurrent PB in RB, and 23.08% vice versa. Prevalence rates of recurrent PB or RB did not differ by gender, weight status, educational or migration history from those without recurrent behaviours. Adults with v. without recurrent PB and RB showed more symptoms of ARFID, general eating disorders depression and anxiety, and behavioural symptoms of eating disorders (with the exception of compensatory behaviours in recurrent PB), and less positive body image. However, there were no differences regarding age and body mass index.

CONCLUSIONS

Our findings highlight the clinical significance of PB and RB in adults regarding both prevalence and associations with other psychopathological symptoms. In particular, associations with body image need to be investigated further, as in contrast to other eating disorders, body image disturbance is not yet represented in the diagnostic criteria for pica and rumination disorder. In sum, the findings highlight the need for clinical attention for these disorders and related behaviours in adults.

Prevalence of restless legs syndrome in people with diabetes mellitus: A pooling analysis of observational studies

BACKGROUND

Diabetes mellitus (DM) is associated with different clinical complications. The aim of this study was to explore the prevalence of RLS in people with diabetes mellitus and compare the risk of restless leg syndrome (RLS) between diabetic and non-diabetic population.

METHODS

We searched for studies of RLS prevalence in DM through PubMed, Embase, and Web of Science. Two authors independently completed the literature screening, data extraction, and bias risk assessment of eligible studies. All observational studies that assessed the prevalence or risk of RLS in DM were included, where the diagnosis of RLS was based on the International Restless Legs Syndrome Study Group (IRLSSG). Percentages, odds ratio (OR) with 95% confidence intervals (CI) were used to assess pooled estimates of RLS prevalence and risk based on random-effects models. Newcastle-Ottawa-scale (NOS) or a modified NOS were used to evaluate the quality of studies.

FINDINGS

A total of 42 studies, including 835,986 participants, met the eligibility criteria for the meta-analysis. Among them, 30 studies were included in meta-analysis to analyze the prevalence of RLS. A second meta-analysis was conducted using 31 studies to determine RLS risk between diabetes and non-diabetes. The results indicate that between 25% (95% confidence interval 21%-29%) of people with diabetes showed signs of RLS, and people with diabetes had an increased risk of developing RLS compare to people without diabetes (OR 1.98, 95%CI 1.66- 2.34, p < 0.001). However, the available evidence was limited due to potential risk of bias and variability between studies (I² >75%), all of observational design.

INTERPRETATION

Our study suggests that the prevalence and risk of RLS might be higher in DM patients than in non-diabetes population. However, given limitations in the analysis and study design, the findings need to be corroborated in future studies.

FUNDING

This work was supported by the Basic Conditions Platform Construction Project of Sichuan Science and Technology Department (2019JDPT0015), and the "1・3・5 project for disciplines of excellence, West China Hospital, Sichuan University" (ZYJC18003).

Restless legs syndrome

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

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.

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.

'Is RLS a harbinger and consequence of MS?: Striking results of the 'RELOMS-T' study'

BACKGROUND

Although studies report a high prevalence rate of restless legs syndrome (RLS) among patients with multiple sclerosis (PwMS) ranging from 13.3 to 65.1%, little is known about the causes of this relationship.

METHODS

To ascertain the prevalence, features and impact of RLS among PwMS a nation-wide, multicenter, prospective and a cross-sectional survey, designed to reflect all of the PwMS throughout Turkey, was conducted in 13 centers. Exploring the relationship of the two conditions could possibly contribute to the understanding of the causes of the high and wide-ranging prevalence rates and the pathophysiology of both diseases.

RESULTS

Of the 1068 participants 173 (16,2%) found to have RLS [RLS(+)] and 895 (83,8%) did not [RLS(-)]. Among the RLS(+) 173, all but 8 patients (4,6%) were underdiagnosed in terms of RLS. More than half of the patients with RLS had 'severe' or 'very severe' RLS. The onset of RLS was before or synchronous with the onset of MS in about a half of our patients.

CONCLUSION

We conclude that RLS should be meticulously investigated in PwMS and MS can be a direct cause of RLS at least in part of PwMS. Our data about the timing of the onset of MS and RLS, along with the high prevalence of RLS in PwMS suggest that the pathologic changes in the initial phases of MS can possibly trigger RLS symptoms.

The prevalence of common sleep disorders in young adults: a descriptive population-based study

Sleep disorders in adults are associated with adverse health effects including reduced quality of life and increased mortality. However, there is little information on sleep disorders in young adults. A cross-sectional observational study was undertaken in 1,227 young adults participating in the Western Australian Pregnancy (Raine) Study (2012–2014) to describe the prevalence of common sleep disorders. In-laboratory polysomnography (PSG) and validated survey methods were used, including the Epworth Sleepiness Scale, Pittsburgh Sleep Symptom Questionnaire-Insomnia, and International Restless Legs Syndrome Study Group criteria. A total of 1,146 participants completed a core questionnaire, 1,051 completed a sleep-focused questionnaire and 935 had analyzable PSG data. Participants had a mean age of 22.2 years and female to male ratio of 1.1 to 1. The respective sleep disorder prevalences in females and males were: obstructive sleep apnea (OSA) (apnea-hypopnea index [AHI]: ≥5 events/hour) 14.9% (95% CI: 11.8–18.5) and 26.9% (95% CI: 22.9–31.2); chronic insomnia, 19.3% (95% CI: 16.7–23.9) and 10.6% (95% CI: 8.3–13.9); restless legs syndrome, 3.8% (95% CI: 2.4–5.6) and 1.9% (95% CI: 0.9–3.4); and abnormal periodic leg movements during sleep (&gt;5 movements/hour), 8.6% (95% CI: 6.3–11.5) and 9.6% (95% CI: 7.1–12.7). There were statistically significant differences in prevalence between sexes for OSA and insomnia, which persisted after adjustment for body mass index and education. In those with complete data on all sleep-related assessments (n = 836), at least one sleep disorder was present in 41.0% of females and 42.3% of males. Sleep disorders are very common in young adults. Health practitioners should be aware of these high prevalences, as early identification and treatment can improve quality of life and may reduce later morbidity and mortality.

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

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

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

Background

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

Methods

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

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

Discussion

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

Trial registration

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

Electronic supplementary material

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

Prevalence of restless legs symptoms according to depressive symptoms and depression type: a cross-sectional study

BACKGROUND

Restless legs syndrome is a sensorimotor disorder and it is associated with several other diseases especially mental illnesses.

AIMS

To analyze the relationship between the symptoms of restless legs syndrome and the severity of depressive symptoms and the prevalence of restless legs symptoms in depression subtypes.

METHODS

A cross-sectional study of primary care patients in the Central Finland Hospital District. The prevalence of restless legs symptoms was studied in 706 patients with increased depressive symptoms and 426 controls without a psychiatric diagnosis by using a structured questionnaire. The depressive symptoms were evaluated with the Beck Depression Inventory (BDI) and the psychiatric diagnosis was confirmed by means of a diagnostic interview (Mini-International Neuropsychiatric Interview). The subjects with increased depressive symptoms were divided into three groups (subjects with depressive symptoms without a depression diagnosis, melancholic depression and non-melancholic depression).

RESULTS

In the whole study population, the prevalence of restless legs symptoms increased with the severity of depressive symptoms. The prevalence of restless legs symptoms was highest in the melancholic and non-melancholic depressive patients (52 and 46%, respectively) and then in subjects with depressive symptoms without a depression diagnosis (43.4%), but the prevalence was also substantial (24.6%) in subjects without a psychiatric diagnosis.

CONCLUSIONS

Restless legs symptoms are very common in primary care among subjects with depression, regardless of the depression type. The prevalence of restless legs symptoms increased with increasing severity of depressive symptoms, regardless of the diagnosis. These findings should be considered in clinical evaluation and treatment of patients visiting their physician due to restless legs or depressive symptoms.

Repetitive Transcranial Magnetic Stimulation for the Treatment of Restless Legs Syndrome

Background:

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive technique used to alter cortex excitability that has been proposed as an efficient method for treating brain hyperexcitability or hypoexcitability disorders. The aim of this study was to investigate whether high-frequency rTMS could have any beneficial effects in restless legs syndrome (RLS).

Methods:

Fourteen patients with RLS were given high-frequency rTMS (15 Hz, 100% motor threshold) to the leg representation motor cortex area of the frontal lobe for 14 sessions over 18 days. Patients were diagnosed according to the international criteria proposed by the International Restless Legs Syndrome Study Group in 2003. The International RLS Rating Scale (IRLS-RS), Pittsburgh Sleep Quality Index (PSQI), Hamilton Anxiety Scale (HAMA) and Hamilton Depression Scale were used to evaluate the severity of RLS, sleep quality, anxiety and depression, respectively. The scale scores were evaluated at four-time points (baseline, end of the 14^th session, and at 1- and 2-month posttreatment). One-way analysis of variance was used to compare scale scores at different time points.

Results:

There was significant improvement in the IRLS-RS (from 23.86 ± 5.88 to 11.21 ± 7.23, P < 0.05), PSQI (from 15.00 ± 4.88 to 9.29 ± 3.91, P < 0.05), and HAMA (from 17.93 ± 7.11 to 10.36 ± 7.13, P < 0.05) scale scores at the end of 14^th session, with ongoing effects lasting for at least 2 months.

Conclusions:

High-frequency rTMS can markedly alleviate the motor system symptoms, sleep disturbances, and anxiety in RLS patients. These results suggest that rTMS might be an option for treating RLS.

Defining the phenotype of restless legs syndrome/Willis-Ekbom disease (RLS/WED): a clinical and polysomnographic study

Clinical features variability between familial and sporadic restless legs syndrome/Willis-Ekbom disease (RLS/WED) has been previously reported. With this retrospective cohort study, we aimed to determine the clinical and polysomnographic characteristics of 400 RLS/WED patients. Patients with familial RLS/WED were significantly younger than sporadic RLS/WED, while clinical and polysomnographic characteristics were similar in both groups. No difference was found for the age-at-onset between idiopathic and secondary RLS/WED. Periodic limb movements (PLM) index and REM sleep time were higher in idiopathic RLS/WED. Time of onset of symptoms was in the evening or at bedtime in 28.04 and 37.80% of patients, respectively, while in 21.34% of patients onset was more than 1 h after sleep onset. Impulse control and compulsive behaviours (ICBs) were found in 13.29% patients on dopamine agonist therapy. Our analyses support the hypothesis that patients with a familial history of RLS/WED may have a genetic component. Nevertheless, the dichotomy between early and late onset disease seems to be less sharp than previously reported. A large proportion of RLS/WED patients can have atypical features, therefore making the diagnosis challenging. Some cases can be missed even when the patient refers to a sleep specialist, as revealed by the partial absence of daytime symptoms, the high comorbidity with insomnia and other sleep complaints and the high percentage of symptoms beginning after sleep onset. This draws attention on the importance of a careful evaluation of the patient, to recognize potentially treatable secondary forms of RLS/WED.

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.

Augmentation of restless leg syndrome (Willis-Ekbom disease) during long-term dopaminergic treatment

Restless legs syndrome (RLS), also known as Willis-Ekbom disease (WED), is a common sensorimotor disorder that can generally be effectively managed in the primary care clinic. However, some treatment complications may arise. According to the recommendations of the International Restless Legs Syndrome Study Group, non-ergot dopamine-receptor agonists have over the past years been one of the first-line treatments for patients with RLS/WED requiring pharmacological therapy. Augmentation is the main complication of long-term dopaminergic treatment of RLS/WED and is defined as an overall worsening of symptoms beyond pretreatment levels in patients who experienced an initial positive therapeutic response. Once identified on the basis of its characteristic clinical features, augmentation requires careful management. In order to provide clinicians with a comprehensive understanding of this common treatment complication, this review discusses the clinical features of augmentation, and its differentiation from morning rebound, symptom fluctuations and natural disease progression. Reported incidences of augmentation in clinical trials of dopaminergic RLS/WED therapies are summarized. Finally, the hypothetical pathophysiology of augmentation and the current recommendations for management of patients with augmented RLS/WED symptoms are discussed.

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.

Sleep disorders in chronic obstructive pulmonary disease: etiology, impact, and management

ABSTRACT

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality and may frequently be complicated by sleep disorders. Insomnia and obstructive sleep apnea are commonly encountered in patients with COPD. Nocturnal hypoxemia is also prevalent in COPD may occur despite adequate awake oxygenation and can be especially severe in rapid eye movement sleep. Additionally, several factors--some of them unique to COPD--can contribute to sleep-related hypoventilation. Recognition of hypoventilation can be vital as supplemental oxygen therapy itself can acutely worsen hypoventilation and lead to disastrous consequences. Finally, accruing data establish an association between restless leg syndrome and COPD--an association that may be driven by hypoxemia and/or hypercapnia. Comorbid sleep disorders portend worse sleep quality, diminished quality of life, and multifarious other adverse consequences. The awareness and knowledge regarding sleep comorbidities in COPD has continued to evolve over past many years. There are still several lacunae, however, in our understanding of the etiologies, impact, and therapies of sleep disorders, specifically in patients with COPD. This review summarizes the latest concepts in prevalence, pathogenesis, diagnosis, and management of diverse sleep disorders in COPD.

Patients suffering from restless legs syndrome have low internal locus of control and poor psychological functioning compared to healthy controls

BACKGROUND

Restless legs syndrome (RLS) is a disturbing sensorimotor disorder negatively influencing both sleep and psychological functioning. The aim of the present study was to assess RLS patients with respect to locus of control, sleep-related personality traits, quality of life, and sleep as compared to healthy controls.

METHOD

Thirty-eight patients (18 females and 20 males; mean age: 56.06 years) diagnosed with RLS and an age- and gender-matched control group (n = 42) were recruited. Participants completed a series of questionnaires related to locus of control, personality traits, quality of life, and sleep.

RESULTS

Compared to healthy controls, RLS patients had a lower internal locus of control, unfavourable sleep-related personality traits such as low self-confidence and higher mental arousal, poorer quality of life, and more depressive symptoms. Sleep was also affected. Multiple regression analyses showed that a low internal and a high external locus of control were predicted by RLS.

CONCLUSIONS

The pattern of results suggests that RLS is associated with a low locus of control, negative personality traits, and poor quality of life as compared to healthy controls.

Excessive daytime sleepiness in type 2 diabetes

OBJECTIVE

To examine excessive daytime sleepiness (EDS) in type 2 diabetes.

SUBJECTS AND METHODS

Patients (N = 110) were evaluated regarding Epworth Sleepiness Scale (EDS), sleep quality (Pittsburgh Sleep Quality Index), depressive symptoms (Beck Depression Inventory), Restless Legs Syndrome (RLS), risk of obstructive sleep apnea (OSA) (Berlin questionnaire), and comorbidity severity (Charlson Comorbidity Index). Patients were compared with individuals with arterial hypertension and without diabetes.

RESULTS

Diabetic patients had more EDS, depressive symptoms, and higher comorbidity severity than hypertensive patients (p < 0.005). In diabetic patients, poor quality sleep (53.3%), and high risk of OSA (40.9%) and RLS (14.5%) were found; EDS (55.5%) was associated with depressive symptoms present in 44.5% individuals (OR = 1.08; 95% CI: 1.01-1.15), and remained so after data were controlled for age, gender, body mass index, and glycated hemoglobin (OR = 2.27; 95% CI 1.03-5.03).

CONCLUSIONS

Sleep abnormalities are frequent. EDS affects most of the patients and is independently associated with depressive symptoms. Adequate antidepressant therapy should be tested for the effects on EDS.

Diagnosis, comorbidities, and management of restless legs syndrome

OBJECTIVE

This narrative review describes the differential diagnosis of restless legs syndrome, and provides an overview of the evidence for the associations between RLS and potential comorbidities. Secondary causes of RLS and the characteristics of pediatric RLS are also discussed. Finally, management strategies for RLS are summarized.

METHODS

The review began with a comprehensive PubMed search for 'restless legs syndrome/Willis-Ekbom disease' in combination with the following: anxiety, arthritis, attention-deficit hyperactivity disorder, cardiac, cardiovascular disease, comorbidities, depression, end-stage renal disease, erectile dysfunction, fibromyalgia, insomnia, kidney disease, liver disease, migraine, mood disorder, multiple sclerosis, narcolepsy, neuropathy, obesity, pain, Parkinson's disease, polyneuropathy, pregnancy, psychiatric disorder, sleep disorder, somatoform pain disorder, and uremia. Additional papers were identified by reviewing the reference lists of retrieved publications.

RESULTS AND CONCLUSIONS

Although clinical diagnosis of RLS can be straightforward, diagnostic challenges may arise when patients present with comorbid conditions. Comorbidities of RLS include insomnia, depressive and anxiety disorders, and pain disorders. Differential diagnosis is particularly important, as some of the medications used to treat insomnia and depression may exacerbate RLS symptoms. Appropriate diagnosis and management of RLS symptoms may benefit patient well-being and, in some cases, may lessen comorbid disease burden. Therefore, it is important that physicians are aware of the presence of RLS when treating patients with conditions that commonly co-occur with the disorder.

Restless legs syndrome/Willis-Ekbom disease diagnostic criteria: updated International Restless Legs Syndrome Study Group (IRLSSG) consensus criteria--history, rationale, description, and significance

BACKGROUND

In 2003, following a workshop at the National Institutes of Health, the International Restless Legs Syndrome Study Group (IRLSSG) developed updated diagnostic criteria for restless legs syndrome/Willis-Ekbom disease (RLS/WED). These criteria were integral to major advances in research, notably in epidemiology, biology, and treatment of RLS/WED. However, extensive review of accumulating literature based on the 2003 NIH/IRLSSG criteria led to efforts to improve the diagnostic criteria further.

METHODS

The clinical standards workshop, sponsored by the WED Foundation and IRLSSG in 2008, started a four-year process for updating the diagnostic criteria. That process included a rigorous review of research advances and input from clinical experts across multiple disciplines. After broad consensus was attained, the criteria were formally approved by the IRLSSG executive committee and membership.

RESULTS

Major changes are: (i) addition of a fifth essential criterion, differential diagnosis, to improve specificity by requiring that RLS/WED symptoms not be confused with similar symptoms from other conditions; (ii) addition of a specifier to delineate clinically significant RLS/WED; (iii) addition of course specifiers to classify RLS/WED as chronic-persistent or intermittent; and (iv) merging of the pediatric with the adult diagnostic criteria. Also discussed are supportive features and clinical aspects that are important in the diagnostic evaluation.

CONCLUSIONS

The IRLSSG consensus criteria for RLS/WED represent an international, interdisciplinary, and collaborative effort intended to improve clinical practice and promote further research.

Pre-pregnancy restless legs syndrome (Willis-Ekbom Disease) is associated with perinatal depression

OBJECTIVES

Both restless legs syndrome ([RLS], also known as Willis-Ekbom Disease [WED]) and depression are common during pregnancy. However, no prior studies have assessed if pregnant women with RLS have an elevated risk of depression during and/or after pregnancy.

METHODS

1,428 women who were pregnant in gestational week 16-17 were asked to participate in a longitudinal survey. They were followed by web-based questionnaires in gestational week 17 and 32, and 6 weeks after delivery. Data were also retrieved from prenatal and birth records. Two different sets of criteria were used to examine the prevalence of RLS in the cohort (International Restless Legs Syndrome Society Group standard criteria and the later developed CH-RLSQ11 questionnaire). The latter questionnaire attempts to exclude those with common "mimics" of RLS.

RESULTS

Adjusted odds ratio for depression in gestational week 17, 32, and postpartum week 6 in relation to pre-pregnancy RLS onset and moderate to severe symptom severity were 4.74 (2.30 - 9.76), 3.67 (1.85 - 7.28), and 2.58 (1.28 - 5.21), respectively. No significant associations were seen in pregnant women with de novo RLS during pregnancy. When using the standard diagnostic RLS criteria and frequency of symptoms more than 2-3 days per week, the prevalence of RLS was 12.3%. With the CH-RLSQ11 questionnaire and the same threshold for frequency of symptoms the prevalence was 6.5%.

CONCLUSION

Women with RLS onset before pregnancy with moderate or severe symptoms had an increased risk of both antenatal and postnatal depression. The self-reported prevalence of RLS during pregnancy is lower when a questionnaire dealing with "mimics" is used.

Restless legs syndrome in an appalachian primary care population: prevalence, demographic and lifestyle correlates, and burden

BACKGROUND

Restless legs syndrome (RLS) is a common and distressing sensorimotor disorder of unknown etiology. While the epidemiology of RLS has been examined in several North American and European studies, research on RLS and RLS burden in poor, rural populations, including those residing in Appalachia, remains sparse. In this study, we investigated RLS prevalence in an Appalachian primary care population and examined the association of RLS to demographic factors, lifestyle characteristics, sleep quality, and mood disorders.

METHODS

Participants of this anonymous survey study were community-dwelling adults aged ≥ 18 years visiting one of 4 West Virginia primary care clinics. Data gathered included detailed information on sleep patterns, demographic characteristics, lifestyle factors, and health/medical history; the survey also included questions specific to RLS diagnosis and severity. Response rates were excellent, with 68% of eligible adults contacted returning completed surveys (N = 1,424/2,087). Pregnant women (N = 65) and those with missing data on key variables (N = 142) were excluded from the analyses.

RESULTS

Of the 1,217 participants included in the final analytic sample, 19.6% (18.2% with symptoms at least once/month) met the 4 IRLSSG diagnostic criteria in the absence of positional discomfort or leg cramps; 14.5% reported RLS symptoms at least once/week and 10.1% indicated symptoms ≥ 3×/week. Excluding respondents with diabetes, kidney disease, or anemia reduced these rates only slightly. Those with RLS were more likely to be older, female, lower income, unemployed, disabled, non-Hispanic white, and less likely to be college educated than those without RLS. Mood and sleep impairment were significantly elevated in those with RLS; after adjustment for demographic and lifestyle characteristics, health history, and other factors, those with RLS remained significantly more likely to indicate a history of depression (adjusted odds ratio [OR] = 1.9; 95% confidence interval [CI] = 1.4, 2.6) and anxiety (OR = 1.6, CI 1.1, 2.2), to report sleep impairment both 4 (OR = 2.4, CI 1.6, 3.7) and 7 days/week (OR = 1.8, CI 1.3, 2.4), and a mean sleep duration < 5 h/night (OR = 1.7, CI 1.2, 2.3). These associations increased in both strength and magnitude with increasing symptom frequency (p's for trend ≤ 0.01).

CONCLUSIONS

Findings of this preliminary anonymous survey study suggest that RLS prevalence is high in this Appalachian primary care population and that RLS is associated with significant burden in terms of both mood and sleep impairment.

Reliability, validity, and responsiveness of the Japanese version of International Restless Legs Syndrome Study Group rating scale for restless legs syndrome in a clinical trial setting

AIM

This study was conducted to verify the reliability, validity, and responsiveness of the Japanese version of the International Restless Legs Syndrome Study Group Rating Scale for restless legs syndrome (J-IRLS) as a sub-study of a clinical trial of pramipexole against restless legs syndrome.

METHODS

After evaluating the test-retest reliability, concurrent validity and construct validity were analyzed. The responsiveness of J-IRLS was confirmed by evaluating the correlations between the changes in J-IRLS total score after treatment, Clinical Global Impression Improvement Scale (CGI-I), and Patient Global Impression.

RESULTS

Test-retest reliability of J-IRLS was good (intra-class correlation coefficient, 0.877; 95% confidence interval, 0.802-0.925). The correlation coefficient of J-IRLS total score and CGI-S score for the first and second visit was 0.804 and 0.796, respectively (both P < 0.0001). Factor analysis of J-IRLS itemsalone identified a two-factor structure. Exploratory analysis on 10 items of J-IRLS together with the Japanese version of the Pittsburgh Sleep Quality Index revealed that several items on the Japanese version of the Pittsburgh Sleep Quality Index appeared as the third factor. The correlations of CGI-I and Patient Global Impression with change in J-IRLS total score after treatment were highly significant.

CONCLUSIONS

Reliability, validity, and responsiveness of J-IRLS were considered adequate. The scale is highly applicable both for evaluating the severity of restless legs syndrome and for assessing drug efficacy.

A study examining depression in restless legs syndrome

BACKGROUND

Distress is known to occur in RLS subjects consequent to symptoms. However, studies regarding prevalence of depression in RLS are scarce. This study was conducted to find out prevalence of depression in RLS patients and to explore possible underlying factors.

METHOD

112 consecutive RLS subjects presenting to sleep-clinic were included in this study. History regarding RLS, depression and sleep-disturbances was sought. Depression and insomnia were diagnosed using DSM-IV-TR criteria. Subjects were specifically asked whether they had depressive episodes in past one year. Severity of RLS and insomnia was measured using Hindi versions of IRLS and ISI, respectively. Family history of depression and RLS was also asked.

RESULTS

One year prevalence of depression was 41.8%. MDD was reported by 33% and dysthymia by 8.8%. Both the groups were comparable with respects to demographic and clinical features, viz., age, gender, duration, severity and family history of RLS. Duration, number of episodes and severity of insomnia were comparable between groups, so was the family history of depression. In 37.8% of the subjects with MDD, depressive symptoms preceded RLS while in 51.4% of them, they followed onset of RLS. Total duration of RLS symptoms did not correlate with total duration of depression (r(2)=0.07; P=0.64).

CONCLUSION

Clinical depression is seen in more than a third of RLS patients. Depression is not affected by clinical picture of RLS and it is not consequent to sleep disturbance. Perhaps, it is a co-morbid condition.

Prospective study of restless legs syndrome and risk of depression in women

Most research on the association between restless legs syndrome (RLS) and depression has involved cross-sectional data. The objective of the present study was to evaluate this issue prospectively among Nurses' Health Study participants. A total of 56,399 women (mean age = 68 years) who were free of depression symptoms at baseline (2002) were followed until 2008. Physician-diagnosed RLS was self-reported. During 300,155 person-years of follow-up, the authors identified 1,268 incident cases of clinical depression (regular use of antidepressant medication and physician-diagnosed depression). Women with RLS at baseline were more likely to develop clinical depression (multivariate-adjusted relative risk (RR) = 1.5, 95% confidence interval (CI): 1.1, 2.1; P = 0.02) than those without RLS. The presence of RLS at baseline was also associated with higher scores on the 10-item Center for Epidemiologic Studies Depression Scale (CESD-10) and the 15-item Geriatric Depression Scale (GDS-15) thereafter. Multivariable-adjusted mean differences were 1.00 (standard error, 0.12) for CESD-10 score and 0.47 (standard error, 0.07) for GDS-15 score between women with RLS and those without RLS (P < 0.0001). In conclusion, women with physician-diagnosed RLS had an increased risk of developing clinical depression and clinically relevant depression symptoms. Further prospective studies using refined approaches to ascertainment of RLS and depression are warranted.

Determining the level of sleepiness in the American population and its correlates

OBJECTIVE

To assess the prevalence, to determine the risk factors and to evaluate the impacts of excessive sleepiness in the general population.

METHOD

It is a cross-sectional telephone study using a representative sample consisting of 8937 non-institutionalized individuals aged 18 or over living in Texas, New York and California. They represented a total of 62.8 million inhabitants. The participation rate was 85.6% in California, 81.3% in New York and 83.2% in Texas. Interviews were managed by the Sleep-EVAL expert system. The questionnaire included questions on sleeping habits, life habits, health, DSM-IV mental disorders, DSM-IV and ICSD sleep disorders.

RESULTS

As many as 19.5% of the sample reported having moderate excessive sleepiness and 11.0% reported severe excessive sleepiness. Moderate excessive sleepiness was comparable between men and women but severe excessive sleepiness was higher in women (8.6% vs. 13.0%). Factors associated with moderate excessive sleepiness were sleeping 6 h or less per main sleep episode (OR:2.0); OSAS (OR:2.0); insomnia disorder (OR:2.4); Restless Legs Syndrome (OR: 1.8) major depressive disorder (OR: 1.7); anxiety disorder (OR:1.5) and use of tricyclic antidepressant (OR: 2.1) presence of heart disease (OR: 1.5), cancer (1.8) and chronic pain (1.3). Factors associated with severe excessive sleepiness were similar with the addition of being a woman (OR:1.5), alcohol dependence (OR: 1.4), bipolar disorder (OR: 2.1), use of over-the-counter sleeping pills (OR: 2.5), narcotic analgesics (OR: 3.4), Antidepressants (other than SSRI or tricyclic) and presence of gastro-esophageal reflux disease (OR:1.6). Sleepy individuals were twice as likely than non-sleepy participants to have had accidents while they were at the wheel of a vehicle during the previous year.

CONCLUSIONS

Excessive sleepiness is highly prevalent in the American population. It was strongly associated with insufficient sleep and various sleep disorders as well as mental and organic diseases.

Restless legs syndrome: a comprehensive overview on its epidemiology, risk factors, and treatment

PURPOSES

Restless legs syndrome (RLS) is underdiagnosed and poorly understood by clinicians and the general public alike; accordingly, a broad literature review with information most relevant to general practice is needed to help dispel misconceptions and improve level of care.

METHODS

Specifically, this review comprehensively provides an epidemiological analysis of RLS and examines the risk factors and treatment options for RLS by compiling the findings of past RLS studies. These RLS studies were identified through a retrospective PubMed search. The epidemiological analysis was conducted by calculating a weighted mean average of all the relevant general population RLS prevalence studies, separated into geographical/racial categories.

RESULTS

A comprehensive analysis of RLS epidemiological studies finds the prevalence rate of RLS to be 5-15% in the general population with 2.5% of adults having symptoms severe enough to require medical intervention. Some of the risk factors for RLS include female gender, pregnancy, low iron levels, lower socioeconomic status, poor health, elderly age, comorbidity with Parkinson's disease, positive family history of RLS, and comorbidity with psychiatric disorders. A wide array of treatment options exist for RLS including pharmacological and nonpharmacologic interventions.

CONCLUSIONS

Clinicians' understanding of RLS enigma has recently improved due to the increased intensity of RLS research over the past decade. This review summarizes the current findings in the RLS field as well as providing guidelines for future RLS-related research.

Epidemiology of restless legs syndrome: a synthesis of the literature

Restless legs syndrome (RLS) has gained considerable attention in the recent years: nearly 50 community-based studies have been published in the last decade around the world. The development of strict diagnostic criteria in 1995 and their revision in 2003 helped to stimulate research interest on this syndrome. In community-based surveys, RLS has been studied as: 1) a symptom only, 2) a set of symptoms meeting minimal diagnostic criteria of the international restless legs syndrome study group (IRLSSG), 3) meeting minimal criteria accompanied with a specific frequency and/or severity, and 4) a differential diagnosis. In the first case, prevalence estimates in the general adult population ranged from 9.4% to 15%. In the second case, prevalence ranged from 3.9% to 14.3%. When frequency/severity is added, prevalence ranged from 2.2% to 7.9% and when differential diagnosis is applied prevalence estimates are between 1.9% and 4.6%. In all instances, RLS prevalence is higher in women than in men. It also increases with age in European and North American countries but not in Asian countries. Symptoms of anxiety and depression have been consistently associated with RLS. Overall, individuals with RLS have a poorer health than non-RLS but evidence for specific disease associations is mixed. Future epidemiological studies should focus on systematically adding frequency and severity in the definition of the syndrome in order to minimize the inclusion of cases mimicking RLS.

Prevalence of restless legs syndrome in North American and Western European populations: a systematic review

BACKGROUND

Restless legs syndrome (RLS) is a potentially debilitating sleep disorder that affects a significant percentage of North American and European adults. Although standardized RLS diagnostic criteria are now established and widely accepted, reported prevalence estimates have varied widely. In this paper, we review the literature regarding RLS prevalence in North American and Western European adult populations, examine potential sources of variation, briefly discuss the impact of RLS, and offer recommendations for future research.

METHODS

To identify qualifying studies, we searched 6 scientific databases and scanned bibliographies of relevant review papers and all identified articles. Studies including fewer than 300 participants, that did not use any of the 4 standard diagnostic criteria, were published prior to 1995 or targeted clinical populations were excluded.

RESULTS

Thirty-four papers detailing results of large, population-based studies in 16 North American and Western European countries met our inclusion criteria, including 5 multi-country studies (N=69,992 participants) and 29 single country studies (N=163,188 participants); all but one were cross-sectional. Reported general prevalence rates ranged from 4% to 29% of adults, averaging 14.5±8.0% across studies. Reported prevalence averaged higher in primary care populations than in populations derived from random sampling or geographically defined cohorts (19.5±7.9% vs. 12.3±7.2%). Diagnostic and severity criteria differed considerably among studies, as did inclusion criteria, with corresponding variation in prevalence estimates. Prevalence averaged higher in women and older adults; more limited data suggest race/ethnicity, parity, health status, and other factors may also contribute to the observed variation in prevalence. RLS has profound, negative effects on health, well-being, and quality of life, yet detection rates remain low.

CONCLUSIONS

Collectively, these studies indicate that RLS is a common disorder of major clinical and public health significance in the Western industrialized world, affecting between 4% and 29% of adults. The wide variation in reported prevalence likely reflects differences in demographic factors, health status, and other population characteristics; study population source and sampling frame; and inconsistencies in RLS diagnostic criteria and procedures. Prospective studies and corresponding incidence data on RLS are lacking, hindering the evaluation of both causal factors and sequelae.

Restless legs syndrome and conditions associated with metabolic dysregulation, sympathoadrenal dysfunction, and cardiovascular disease risk: a systematic review

Restless legs syndrome (RLS) is a distressing sleep and sensorimotor disorder that affects a large percentage of adults in the western industrialized world and is associated with profound reductions in quality of life. However, the etiology of RLS remains incompletely understood. Enhanced understanding regarding both the antecedents and sequelae of RLS could shed new light on the pathogenesis of RLS. Evidence from an emerging body of literature suggests associations between RLS and diabetes, hypertension, obesity, and related conditions linked to sympathetic activation and metabolic dysregulation, raising the possibility that these factors may likewise play a significant role in the development and progression of RLS, and could help explain the recently documented associations between RLS and subsequent cardiovascular disease. However, the relation between RLS and these chronic conditions has received relatively little attention to date, although potential implications for the pathogenesis and treatment of RLS could be considerable. In this paper, we systematically review the recently published literature regarding the association of RLS to cardiovascular disease and related risk factors characterized by sympathoadrenal and metabolic dysregulation, discuss potential underlying mechanisms, and outline some possible directions for future research.

Medical comorbidity of sleep disorders

PURPOSE OF REVIEW

Recently published literature indicates that sleep disorders present with medical comorbidities quite frequently. The coexistence of a sleep disorder with a medical disorder has a substantial impact for both the patient and the health system.

RECENT FINDINGS

Insomnia and hypersomnia are highly comorbid with medical conditions, such as chronic pain and diabetes, as well as with various cardiovascular, respiratory, gastrointestinal, urinary and neurological disorders. Restless legs syndrome and periodic leg movement syndrome have been associated with iron deficiency, kidney disease, diabetes, and neurological, autoimmune, cardiovascular and respiratory disorders. Rapid eye movement behaviour disorder has been described as an early manifestation of serious central nervous system diseases; thus, close neurological monitoring of patients referring with this complaint is indicated.

SUMMARY

Identification and management of any sleep disorder in medical patients is important for optimizing the course and prognosis. Of equal importance is the search for undetected medical disorder in patients presenting with sleep disorders.

High incidence of iron depletion and restless leg syndrome (RLS) in regular blood donors: intravenous iron sucrose substitution more effective than oral iron

BACKGROUND AND OBJECTIVES

Iron depletion is common in regular blood donors. The objective of the study was to investigate the frequency and severity of iron depletion in regular blood donors and whether IV iron is more effective than oral to avoid iron depletion and symptoms thereof, especially restless legs syndrome (RLS).

METHOD

One hundred and twenty blood donors with at least five previous whole blood donations were randomized to receive either IV iron sucrose (Venofer(®), RenaPharma/Vifor, Uppsala, Sweden), 200 mg, or to 20×100 mg of oral iron sulphate (Duroferon(®), GlaxoSmithKline, Stockholm, Sweden), after each blood donation during 1 year. Iron status and RLS incidence and severity were investigated.

RESULTS

Iron status was generally poor among regular blood donors, especially in women, with a high incidence of iron depletion (>20%) and RLS (18%). The IV iron group increased storage iron to a greater extent than the oral iron group after 12 months (P=0·0043). Female donors were more responsive to IV iron sucrose compared to oral iron sulphate, particularly female donors below 50 years of age. RLS severity scores were significantly lower in the IV iron group. The two treatments were safe.

CONCLUSION

Iron status is poor in regular blood donors, restless legs syndrome is common, and the routine iron supplementation is insufficient. IV iron sucrose substitutes iron loss in blood donors more efficiently compared with oral iron sulphate, especially in women. Iron substitution to blood donors should be individualized and based on P-ferritin monitoring.

Restless legs syndrome

Restless legs syndrome (RLS) is characterized by a compelling, often insatiable, need to move the legs, accompanied by unpleasant sensations located mainly in the ankles and calves. Because symptoms are brought on by inactivity, distress intrudes upon everyday, sedentary activities such as plane travel, car rides, and attending school, meetings, or the theatre. Symptoms show a diurnal preference for the evening and night, so disruption of sleep onset or maintenance is particularly common. RLS is associated with both lower ratings of quality of life and higher rates of cardiovascular disease. Four common genetic loci associating to RLS have recently been identified, but the molecular pathways by which they increase risk for RLS have yet to be determined. Both sensory (RLS) and motor (periodic limb movements of sleep) symptoms are responsive to dopaminergic medications, yet clear delineation of dopaminergic pathology has not emerged. Brain iron is reduced in many, but not all, patients with RLS. First-line treatment for RLS includes agents acting at D(2) and D(3) dopamine receptors.

Health-related quality of life and restless legs syndrome among women in Sweden

AIM

Restless legs syndrome (RLS) is a common neurological movement disorder with a female preponderance, an increasing prevalence with age and comorbidity. Previous studies on the relationship between health-related quality of life (HRQOL) and RLS are still sparse but knowledge is increasing. The aim of this study was to evaluate the unique impact of RLS on HRQOL in a population-based sample.

METHODS

A random sample of 5000 women aged 25-64 years was selected from the general Swedish population. The women were sent diagnostic questions on RLS together with the Short Form 12 (SF-12) questionnaire for assessment of physical and mental HRQOL. The unique burden of RLS on HRQOL was analyzed by excluding RLS-positive women from four self-reported diagnostic groups (diabetes, depression, heart problems, muscle and joint pain) and by excluding subjects with these diagnoses from the group of RLS-positive women.

RESULTS

Compared with mental SF-12 scores for the RLS-negative women in our population, mental HRQOL of the RLS sample in our study was lower in every age group but not significantly lower in the age group 35-44 years. Physical SF-12 scores for RLS-positive women were also below scores for RLS-negative women in every age group but significance was only found in women between 45 and 54 years. A unique burden of RLS on HRQOL remained after statistical adjustment for comorbidities.

CONCLUSION

RLS-positive women had an impaired mental HRQOL compared to RLS-negative women in the studied population. The physical aspects of HRQOL were less affected among RLS-positive women. The impaired well-being among women with RLS further strengthens the importance of identifying women with this condition and evaluating their need for medication or other actions in order to improve their quality of life.

Prevalence and associated factors of restless legs in a 57-year-old urban population in northern Finland

OBJECTIVE

We examined the prevalence and associated factors of restless legs syndrome (RLS) in a 57-year-old unselected urban population in northern Finland.

METHODS

A health survey was conducted in 2002 that targeted persons born in 1945 and residing in the city of Oulu on 31 December, 2001. Their history of RLS, coronary heart disease (CHD), daytime sleepiness, depressive symptoms and snoring was assessed by means of questionnaires.

RESULTS

Altogether 995 of 1332 eligible subjects (74%) participated (556 women, 439 men). The overall prevalence of RLS > or = 1 per week was 20% in women and 15% in men. In the fitted multiple logistic regression model, RLS was found to be associated with female gender (OR 1.64, 95% CI 0.98-2.72), CHD (OR 2.92, 95% CI 1.18-7.23), daytime sleepiness (OR 2.12, 95% CI 1.32-3.41), moderately elevated (31-45) or high (46-65) Zung sum scores (OR 1.95, 95% CI 1.09-3.48 and OR 3.67, 95% CI 1.71-7.90, respectively), antidepressant medication (OR 2.10, 95% CI 1.06-4.19) and arthropathy (OR 1.69, 95% CI 1.04-2.72). Insufficient evidence was found of an association between RLS and type 2 diabetes or impaired glucose regulation.

CONCLUSIONS

Restless legs syndrome is fairly common in subjects aged 57 years. A particularly strong positive association was observed between RLS and depressive symptoms and CHD.

Depressive disorders in restless legs syndrome: epidemiology, pathophysiology and management

Epidemiological studies report a 2- to 4-fold risk of a depressive disorder in patients with restless legs syndrome (RLS) compared with healthy controls. The high prevalence rates of depression in RLS indicate an association between the two disorders. Severe sleep disturbance due to the nightly occurrence of RLS symptoms is a common complaint of patients with moderate or severe RLS and may substantially contribute to the emergence of depressive symptoms. Difficulty in the diagnosis of a depressive disorder in patients with RLS may arise from the overlap of symptoms in the two disorders, as sleep-related complaints are frequent both in RLS and depression. The treatment of depression in RLS has some unique aspects, as several antidepressants have been reported to trigger or worsen RLS. To date, no studies have been published regarding the course of depression in untreated and treated patients with RLS. On the other hand, the presence of co-morbid depression can have a substantial impact on the global treatment outcome. In patients with co-morbid moderate/severe depression, antidepressant therapy in parallel with or shortly after commencing RLS treatment is usually necessary. Data from recent trials with dopamine receptor agonists indicate that mild to moderate depressive symptoms are often relieved with improvement of RLS symptoms.

Prevalence and clinical correlates of restless legs syndrome in an elderly French population: the synapse study

BACKGROUND

The occurrence of restless legs syndrome (RLS) in elderly individuals is well known but the incidence and the clinical correlates in these subjects are still unclear. The present study explores the prevalence of and assesses symptoms associated with RLS in an older French population.

METHODS

The study sample for this study comprised 318 subjects (219 women and 99 men), aged 68.6 +/- 0.8 years. All subjects underwent clinical assessment, nocturnal polygraphy, and cognitive and mood disorders evaluation. RLS was assessed with the standard validated criteria and severity was evaluated by the use of International Restless Legs Syndrome Study Group (IRLS) questionnaire.

RESULTS

RLS was present in 24.2% of the sample, prevalence being greater in women (29.7%) than in men (12.1%). The mean IRLS score was 16.6 +/- 4.8, 67% of cases having mild to moderate range. Participants with RLS reported greater hypnotic (p < .001) and antidepressant medication intake (p < .001) and had higher anxiety (p < .001) and depression (p < .001) scores. Participants with RLS had lower cognitive performances at Stroop and Verbal fluency tests than participants without RLS (p < .05 and p = .002, respectively). These associations remained significant after multivariate adjustment for medication, depression, and subjective sleep.

CONCLUSIONS

Presence of undiagnosed RLS is higher in healthy elderly participants without previously diagnosed sleep disorders, affecting women more often than men. The presence of RLS increased the risk of anxiety and mood disorders and predispose to preclinical cognitive decline independently of anxiety, mood disorders, duration and quality of sleep, and medication.