Prevalence Of Restless Legs Syndrome Research Articles

The prevalence of restless legs syndrome in chronic obstructive pulmonary disease (COPD) patients

To investigate the prevalence of restless legs syndrome (RLS) in chronic obstructive pulmonary disease (COPD) patients. The symptoms and severity of RLS was evaluated by the International Restless Legs Syndrome Group Study (IRLSSG). Mann–Whitney U test, Chi-square test and Spearman correlation coefficient were used to analyze the data. Out of the 109 COPD patients, 18.3% were diagnosed with RLS. There is no statistically significant difference between RLS and non-RLS groups except the mean age (P value > 0.05). Restless legs syndrome is relatively common in patients with COPD.

Prevalence of restless leg syndrome in Mongolian adults: Mon-TimeLine study.

We conducted an epidemiologic study based on survey neuroscience screening for restless leg syndrome in the Mongolian to determine the prevalence of restless leg syndrome. We used baseline data from the Mon-TimeLine study, a multidisciplinary, prospective, population-based cohort study. The total number of participants (n = 1572) ranged from 18 to 65 years of age. We found the prevalence of restless leg syndrome to be 6.6% (n = 103), among which 4.1% (n = 16) were males and 7.3% (n = 87) were females. The peak prevalence age for both genders was 45-55, and we found a positive correlation with body mass index (P < 0.05). Most cases were mild (44.7%) or moderate (35.9%), but 18.4% and 1% of the cases were severe or very severe, respectively. The severe groups showed a positive association with chronic kidney disease, as well as with gastritis. In conclusion, the prevalence of restless leg syndrome in Mongolia approximates that in other countries.

Restless leg syndrome in adult patients with β-thalassemia major.

To investigate the quality of sleep and the presence of Restless Legs Syndrome (RLS) in the Turkish population with β-thalassemia major (TM). The second aim was to assess the risk factors of RLS in TM adults. The study sample comprised of 121 patients at least 18 years old with TM. The patients' socio-demographic information, body mass indexes (BMI), current medications, laboratory data were recorded. The patients were asked if they had a history of chronic kidney disease, diabetes mellitus (DM), and polyneuropathy. Restless legs syndrome was diagnosed according to the International Restless Legs Syndrome Study Group criteria. The sleep quality of the patients was assessed using the Pittsburgh Sleep Quality Index (PSQI) scale. The Epworth Sleepiness Scale (ESS) was used to assess excessive daytime sleepiness in the patients. The median age of the patients was 25 years (range 18-52). The mean BMI was 21.49±2.5 (R 14-26.5) for all patients. The prevalence of RLS was 5% in TM adult patients. The TM patients with RLS had no major complications of TM. The median PSQI global score of all patients was 3. Twenty-two (18.1%) patients had poor sleep quality. The reason for poor sleep quality was RLS symptoms in four patients (18%). There was no significant association between PSQI total score and blood parameters of the patients. Twelve (9.9%) patients had ESS scores greater than 10, which indicates excessive daytime sleepiness. The prevalence of RLS in TM patients was similar to that of the general Turkish adult population. These results indicate that RLS may occur in patients with TM, although they had a high level of serum ferritin.

Restless legs syndrome in Parkinson's disease: relationship with quality of life and medication.

We aimed to disclose the relationship between restless leg syndrome (RLS) and antiparkinsonian treatment, and its effect on quality of life (QoL) in patients with Parkinson's disease (PD). Previous studies documented the prevalence of RLS among patients with PD to be higher than in the general population, but conclusions regarding the aetiology and impact were contradictory. We examined 101 patients with idiopathic PD. All participants completed the five-dimension/five-level-EuroQoL questionnaire (EQ-5D-5L) and the International Restless-Legs-syndrome-study-group rating Scale (IRLS). The prevalence of RLS was 22.77 %. There were no statistically significant differences in levodopa or dopamine agonists (DA) doses between RLS-positive and negative participants. However, the use of levodopa as the last night-time medication was connected with a higher risk of RLS (OR=2.049, p=0.041). There was significantly lower prevalence of RLS in patients after surgical treatment for PD (p=0.024). Participants with RLS were at a greater risk for sleep disturbances (OR=3.866, p=0.023) and excessive daytime sleepiness (OR=7.202, p<0.001). Greater RLS symptoms were associated with worse QoL (higher IRLS score predicted higher EQ5D5L score, p=0.023). RLS is prevalent among PD patients and night-time dopaminergic over-excitation with levodopa plays an important role in its pathogenesis. Since the symptoms of RLS are associated with decreased QoL, early accurate diagnosis and appropriate adjustment of dopaminergic therapy can lead to immediate relief from RLS symptoms and to QoL improvement (Tab. 4, Fig. 1, Ref. 34).

Prevalence, severity and associated factors of restless leg syndrome in inflammatory bowel disease patients

Background:The association between restless leg syndrome (RLS) and inflammatory bowel disease (IBD) has often been an under-investigated and clinically misdiagnosed entity. An emphasis should be made on the severity and associated factors, as the prevalence of both entities is on the rise globally. In this study we aimed to investigate the prevalence, severity and associated risk factors of RLS in patients with IBD.Methods:A multi-center, prospective cross-sectional study was conducted with age and gender matched controls in the ratio of 1:3. Cases of IBD were confirmed according to European Crohns and Colitis Organization guidelines. The study recruited 377 cases and 1131 age and gender-matched controls. RLS severity and prevalence was determined using a validated International Restless Legs Syndrome Study Group questionnaire. The anthropometric and blood biochemical measurements were retrieved from the patient's medical records. Associated factors were analyzed by regression analysis.Results:The prevalence of RLS in patients with IBD and non-IBD control groups was 21.5% and 9.7%, respectively (P = 0.001). The severity index of RLS symptoms in all the three categories of mild, moderate and severe RLS was higher in the IBD group (P = 0.001). Obesity (BMI >30 Kg/m2) was more prevalent in patients with IBD with RLS than without RLS (21.9%: 10.3%, P = 0.009). Ages between 46 and 59 years (OR = 18.7 [2.6–29.4], P = 0.008), obesity (OR = 22 [2.6–29.4], P = 0.005), higher TSH levels (OR = 1.7 [1.0–3.0], P = 0.033), and lower hemoglobin levels (P = 0.028) showed a greater risk associated with RLS.Conclusion:Prevalence and severity of RLS was higher in patients with IBD. The risk factors for RLS in IBD include increasing age, obesity, higher TSH, and lower hemoglobin.

Restless legs syndrome - a study from general practice.

The prevalence of restless legs syndrome (RLS) among adults in the general population is around 5-10%. Few studies have been conducted on the prevalence among patients who consult their general practitioner. There are also few studies on associations between RLS and other common complaints such as irritable bowel syndrome (IBS), chronic fatigue (CF) and chronic muscle and back pain (CMBP). The study was conducted as a questionnaire survey at medical offices in Southern and Western Norway in the autumn of 2017and spring of 2018, when patients waiting to see their general practitioner (GP) were invited to participate. A total of 2634people took part (62.2% women, average age 49.6years). The response rate was 86.8%. Restless legs syndrome (RLS) was defined on the basis of international criteria. Associations between RLS and IBS, CF and CMBP were analysed by means of chi-squared tests and logistic regression. The proportion of patients with RLS was 14.3%. Of the patients with RLS, 44.8% reported that their symptoms were moderately to very distressing, and 85.8% that they did not use medication for it. The proportion of patients with RLS was significantly higher among patients with IBS (21.8% versus 13.6%, p = 0.009), CF (18.2% versus 13.1%, p = 0.003) and CMBP (23.2% versus 12.2%, p < 0.0005). GPs should be aware that many patients have RLS and that the condition is associated with other common complaints.

Dynamic Prevalence of Sleep Disorders Following Stroke or Transient Ischemic Attack: Systematic Review and Meta-Analysis.

The exact prevalence of sleep disorders following stroke or transient ischemic attack (TIA) remains unclear. We aimed to determine the prevalence of sleep-disordered breathing, insomnia, periodic leg movement during sleep, and restless leg syndrome following stroke or TIA in acute, subacute, and chronic phases and examine the moderating effects of patient characteristics (eg, age) and methodological features (eg, study quality) on the prevalence. We performed a systematic review and meta-analysis. Embase and PubMed were searched from inception to December 18, 2019. We included 64 047 adults in 169 studies (prospective, retrospective, case-control, and cross-sectional study designs) reporting the prevalence of sleep disorders following stroke or TIA. In the acute phase, the overall prevalence of mild, moderate, and severe sleep-disordered breathing was 66.8%, 50.3%, and 31.6% (95% CIs, 63.8-69.7, 41.9-58.7, and 24.9-39.1). In the subacute phase, the prevalence of mild, moderate, and severe sleep-disordered breathing was 65.5%, 44.3%, and 36.1% (95% CIs, 58.9-71.5, 36.1-52.8, and 22.2-52.8). In the chronic phase, the summary prevalence of mild, moderate, and severe sleep-disordered breathing was 66.2%, 33.1%, and 25.1% (95% CIs, 58.6-73.1, 24.8-42.6, and 10.9-47.6). The prevalence rates of insomnia in the acute, subacute, and chronic phases were 40.7%, 42.6%, and 35.9% (95% CIs, 31.8-50.3, 31.7-54.1, and 28.6-44.0). The pooled prevalence of periodic leg movement during sleep in the acute, subacute, and chronic phases was 32.0%, 27.3%, and 48.2% (95% CIs, 7.4-73.5, 11.6-51.7, and 33.1-63.5). The summary prevalence of restless leg syndrome in the acute and chronic phases was 10.4% and 13.7% (95 CIs, 6.4-16.4 and 2.3-51.8). Age, sex, comorbidities, smoking history, and study region had significant moderating effects on the prevalence of sleep disorders. Sleep disorders following stroke or TIA are highly prevalent over time. Our findings indicate the importance of early screening and treating sleep disorders following stroke or TIA.

Restless Leg Syndrome and Sleep Disorders in Patients with Rheumatoid Arthritis and Its Relation with Anemia Parameters.

We aimed to investigate the prevalence of restless legs syndrome (RLS) and sleep disorders in patients with rheumatoid arthritis (RA), and the association of iron deficiency with them. The study included 72 patients with RA (59 females, 13 males), and 50 healthy control subjects (57 females, 15 males). Assessments were made using the International RLS Rating Scale, Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale, Fatigue Severity Scale (FSS), Beck anxiety and depression index and the SF-36 quality of life scores. We found that the frequency of RLS in RA patients was 29.1% and 13.8% in healthy control (p = 0.021). RA patients had 44.4% iron deficiency and 5.5% anemia of chronic disease. We found that 52.3% of patients with iron deficiency had RLS. There was an independent relationship between present of RLS and FSS (Beta [β] = 0.317, p = 0.005) and total iron binding capacity (TIBC) (β = 0.244, p = 0.031). There was an independent relationship between RLS severity score and PSQI (β = 0.264, p = 0.025) and social functionality (β = 0.302, p = 0.009). The prevalence of iron deficiency is high in RA in the developing countries. Analysis obtained in patients with RA is suggestive of an association between iron deficiency and increased frequency of RLS. The presence of RLS in patients with RA negatively affects sleep quality, psychiatric status, and quality of life of patients with RA. TIBC value may be a predictive marker for early detection of RLS in patients with RA.

Socioeconomic impact of restless legs syndrome and inadequate restless legs syndrome management across European settings.

Restless legs syndrome (RLS) is one of the most common neurological disorders. It describes an irresistible urge to move the legs, mostly manifested in the evening and at night, which can lead to severe sleep disturbance. As part of the European Brain Council (EBC)-led Value-of-Treatment project, this study aimed at capturing the socioeconomic impact of RLS related to the inadequate diagnosis and treatment across different European healthcare settings. The economic burden of RLS was estimated using the published EBC framework of analysis in three separate European Union healthcare systems (France, Germany, and Italy). The RLS care pathway was mapped to identify the unmet needs of patients. Based on specific patient stories, the economic impact of correctly diagnosing RLS and changing between inadequate and target treatment was calculated using appropriate scenario analysis. RLS proved to be a significant personal and social burden, when epidemiological data, high prevalence of RLS, and its need for treatment are combined. By looking at the savings emerging from the provision of optimal care management (timely and correct diagnosis, evidence-based therapy, avoidance of therapy-related complications such as augmentation), the authors foresee substantial economic savings with the achievement of adequate diagnosis and treatment of RLS. Education about RLS is urgently needed for all subspecialties involved in RLS patient care as well as the general public. Equally important, the search for new causal treatment strategies should be intensified to reduce suffering and substantial societal cost.

Restless legs syndrome is increased in postural orthostatic tachycardia syndrome.

Postural orthostatic tachycardia syndrome (POTS) and restless legs syndrome (RLS) are both characterized by sleep disturbance along with autoimmune/inflammatory features and autonomic dysfunction. However, to our knowledge, there has been no direct study looking at the prevalence of RLS in patients with POTS patients compared with healthy participants (controls). Ninety-six physician-diagnosed patients with POTS (89 female and 7 male) and 130 controls (99 female and 31 male) were administered the Cambridge Hopkins questionnaire. Participants who were diagnosed with probable or definite RLS on the Cambridge Hopkins questionnaire were then contacted to determine the severity of RLS with the International Restless Legs Scale. More patients with POTS (15 of 96; 15.6%) than controls (6 of 130; 4.6%) were diagnosed with probable or definite RLS on the Cambridge Hopkins questionnaire (P = .0048). A sensitivity analysis with only female respondents yielded similar results. RLS severity was in the moderate range (12.23 ± 9.22). There is a higher prevalence of RLS in patients with POTS patients compared with controls. This association may have to do with shared increased inflammatory/autoimmune load and autonomic dysfunction.

Impact of Medium Cut-Off Dialyzers on Patient-Reported Outcomes: COREXH Registry

Introduction: A new generation of hemodialysis (HD) membranes called medium cut-off (MCO) membranes possesses enhanced capacities for middle molecule clearance, which have been associated with adverse outcomes in this population. These improvements could potentially positively impact patient-reported outcomes (PROs). Objective: The objective of this study was to evaluate the impact of MCO membranes on PROs in a cohort of HD patients in Colombia. Methods: This was a prospective, multicenter, observational cohort study of 992 patients from 12 renal clinics in Colombia who were switched from high-flux HD to MCO therapy and observed for 12 months. Changes in Kidney Disease Quality of Life 36-Item Short Form Survey (KDQoL-SF36) domains, Dialysis Symptom Index (DSI), and restless legs syndrome (RLS) 12 months after switching to MCO membranes were compared with time on high-flux membranes. Repeated measures of ANOVA were used to evaluate changes in KDQoL-SF36 scores; severity scoring was used to assess DSI changes over time; Cochran’s Q test was used to evaluate changes in frequency of diagnostic criteria of RLS. Results: During 12 months of follow-up, 3 of 5 KDQoL-SF36 domains improved compared with baseline: symptoms (p < 0.0001), effects of kidney disease (p < 0.0001), and burden of kidney disease (p < 0.001). The proportion of patients diagnosed with RLS significantly decreased from 22.1% at baseline to 10% at 12 months (p < 0.0001). No significant differences in the number of symptoms (DSI, p = 0.1) were observed, although their severity decreased (p = 0.009). Conclusions: In conventional HD patients, the expanded clearance of large middle molecules with MCO-HD membranes was associated with higher health-related quality of life scores and a decrease in the prevalence of RLS.

Restless legs syndrome/Willis-Ekbom disease in multiple sclerosis: a contributing factor for anxiety, disability, sleep disorder, and quality of life.

Restless legs syndrome (RLS) is one of the most common and burdensome sleep disorders in the course of multiple sclerosis (MS). To evaluate common MS-related symptoms and consequences between groups with and without RLS and further assess the association of quality of life determinants with RLS symptom severity. According to their RLS status, 46 relapsing-remitting MS patients were divided into MS-RLS+ (n=19) and MS-RLS- groups (n=27). Specific questionnaires were administered to assess the patients' health-related quality of life (HRQoL), fatigue levels, sleep quality, daily sleepiness, anxiety, and depression symptoms. Functional capacity was examined using the Expanded Disability Status Scale (EDSS). The prevalence of RLS was 41.3%. Compared to the MS-RLS- group, those with RLS had higher EDSS scores, more cranial and spinal lesions, longer disease duration, and were older. In the MS-RLS+ group, symptom severity scores were positively correlated with higher anxiety and poorer sleep quality. The symptom severity score was negatively correlated with mental HRQoL and pain scores. In conclusion, the findings of the current study indicate the negative impact of RLS on functional capacity, anxiety, sleep quality, and mental HRQoL of MS patients. Further studies using more accurate diagnostic strategies for identifying RLS and other sleep disorders are necessary to clarify the association of MS with RLS and explore relevant clinical implications.

Prevalence of restless leg syndrome (RLS) in Parkinson's disease and its correlation with serum and CSF iron and ferritin levels

Background: Restless leg syndrome is common in PD and may correlate better with levels of iron and ferritin in CSF than in serum.

Prevalence of Restless Legs Syndrome in Iran: A Systematic Review and Meta-Analysis

Introduction: In recent years, different values of the general prevalence of restless legs syndrome (RLS) have been reported in various studies and its related factors in Iranian society are not known. The aim of this study was to evaluate the prevalence and factors associated with RLS in Iran by meta-analysis. Methods: This study was performed based on the PRISMA checklist. There was a time limit from July 1, 2014, to November 11, 2019, for documents obtained from English and Persian databases such as MagIran, SID, MedLib, IranMedex, IranDoc, Civilica, Islamic Science Citation (ISC), Web of Science, Science Direct, Pubmed, Scopus, Springer, and Google Scholar. Comprehensive Meta-analysis (CMA-2) software was used to analyze the data by meta-analysis random- effects model. Results: The prevalence of RLS was estimated to be 32.9% (95% CI: 22.9- 44.7) in 24 studies with 26474 Iranian subjects that 65.9% of whom were women. The prevalence of this disorder was 47.6% in Iranian women (95% CI: 28.7-67.2) and 36.7% in Iranian men (95% CI: 21.4-55.3). The most and the least prevalence of RLS based on the geographical region were respectively in the east (44.3%) and north of the country (15.5%) and this difference was significant based on meta-regression (p &lt;0.05). The prevalence of this syndrome was 50% in hemodialysis patients, 35% in other diseases, 25.7% in pregnant women, 20.2% in elderly and 13.8% in adults. Conclusion: The prevalence of RLS in Iran is higher than in other parts of the world based on different studies. Therefore, early detection, prevention and treatment of this disorder in adults are essential.

Restless Legs Syndrome During Pregnancy and 12 Weeks Postpartum and its Links to Cardiovascular Diseases, Stressful Life Events, and Psychiatric History.

Restless legs syndrome (RLS) is highly prevalent among pregnant women. In the present study, a neurological–obstetrical sample of 561 postpartum women was retrospectively screened for RLS symptoms during pregnancy and in the first 12 weeks postpartum. The first screening took place within 1 to 6 days of delivery (T0) and the second 12 weeks after childbirth (T1). The pregnancy-related RLS prevalence rate was found to be 21% (n = 119), with the women suffering from RLS being more often affected by psychiatric history and having been more exposed to stressful life events. They were also found to have experienced baby blues more frequently shortly after childbirth. However, RLS in pregnancy did not appear to have any effect on the development of postpartum depression. Additionally, a positive trend was observed toward an association between pregnancy-related RLS and gestational diabetes and hypertension. Of the 119 women, 23 (19.3%) remained affected by RLS 12 weeks postpartum. Body mass index (BMI), weight gain, parity, childbearing history, or chronic stress exposure in pregnancy as measured by hair cortisol were not found to be linked to RLS. In summary, a comprehensive understanding of the interaction of clinical, environmental, and anamnestic factors can help shed valuable light on this pregnancy-related condition.

Which Factors in Spinocerebellar Ataxia Type 3 Patients Are Associated with Restless Legs Syndrome/Willis-Ekbom Disease?

There is evidence of a higher prevalence of restless legs syndrome/Willis-Ekbom disease (RLS/WED) in individuals with spinocerebellar ataxia type 3 (SCA3), although the factors underlying this association remain unknown. The present study aimed to determine the prevalence of RLS/WED in SCA3 patients and to investigate which factors of SCA3 patients are associated with presence of RLS/WED. From February to August of 2006, we carried out clinical interviews in 40 controls and 40 SCA3 patients, diagnosed and followed up at Faculty of Medicine of Ribeirão Preto, University of São Paulo. Twenty-seven SCA3 patients were submitted to a detailed clinical protocol, electroneuromyography, blood work up, polysomnography (PSG), suggested immobilization test (SIT), and magnetic resonance image (MRI). RLS/WED was found in 27.5% of SCA3 patients and 2.5% of normal controls (p = 0.003). The factors related to RLS/WED in SCA3 patients were female gender, age at start of the symptoms of ataxia after 30years, presence of peripheral neuropathy, and documented iron deficiency. Among SCA3 patients, those with RLS showed higher values of maximal discomfort level and discomfort level sum compared to non-RLS individuals on SIT. There is a relation between RLS/WED and SCA3, which seems to be resultant of different factors whose identification could improve the quality of assistance to those patients as well as to promote a better comprehension of the pathophysiology of both RLS/WED and SCA3.

Prevalence of restless legs syndrome and quality of sleep in type 2 diabetics.

Restless legs syndrome (RLS) is characterized by an irresistible urge to move, with or without paraesthesia occurring or worsening at rest and relieved by activity. Only a few reports of prevalence of RLS with type 2 diabetes are available in India. To estimate the occurrence and risk factors of RLS among Indian patients with type 2 diabetes mellitus. This cross-sectional study was done in consecutive adult patients with type 2 diabetes. Demographic and comorbidity profile were collected. RLS diagnosis was made based on revised international RLS study group (IRLSSG) criteria. Two hundred and ten diabetic patients were interviewed. Mean age was 56 ± 13.5 years. Male-female ratio was 139: 71. Mean duration of diabetes was 8.3 years. Treatment received for diabetes included oral hypoglycaemic agents (153 patients) and insulin (85 patients). Forty-five patients had polyneuropathy, 18 had retinopathy and 22 had nephropathy. Majority (103) of subjects reported their bedtime as 9-10 pm. Average sleep duration was 8.4 h per night. RLS was diagnosed in 17 (8%) subjects. Mean sleep onset in subjects with RLS was 56 min versus 29 min in diabetics without RLS (p-0.01). The mean Pittsburgh Sleep Quality Index score was 5 in RLS and 3.3 in non-RLS patients (p-0.01). RLS resulted in poor sleep quality and affected overall quality of life in diabetics. As poor sleep is a known risk factor for uncontrolled diabetes, early identification and treatment of RLS would help improve glycaemic control and quality of life in these patients.

Prevalence of Restless Leg Syndrome among Pregnant Women in Lahore City

Restless Legs Syndrome (RLS) is a neurosensory issue that ordinarily starts at night and regularly keeps a man from nodding off. It has been related w i t h p r e s s i n s u f  c i e n c y p a l l o r a n d dopaminergic pathways. Its impact on rest and disposition state and investigate the part of folic acid and iron in the declaration of RLS, particularly amid the third trimester when the disorder is generally upsetting.

The Prevalence of Restless Legs Syndrome in Patients with Migraine: A Systematic Review and Meta-Analysis.

Background Migraine is a severe and debilitating neurologic disorder and is claimed to be the sixth disabling illness in the world. This study aimed to determine the overall prevalence of restless legs syndrome (RLS) in patients with migraine through a systematic review and meta-analysis. Methods To identify and select related studies, the Scopus, ScienceDirect, Embase, SID, IranDoc, Web of Science, Knowledge Network System Medline (PubMed), and Google Scholar databases were searched. All related cross-sectional studies, published in English or Persian language between January 2000 and December 2019 and using the keywords such as migraine, restless leg syndrome, sleep disorder, RLS, and migraine disorder, were collected. The heterogeneity of the studies was assessed using the I2 index, and the data analysis was performed using the Comprehensive Meta-Analysis software. Results Analysis was conducted on the reported results of the final 12 articles with the total sample size of 15196. The overall prevalence of RLS in patients with migraine was 16.3% (95% CI: 12.6–20.8%). The prevalence of RLS migraine patients decreased with increasing the sample size, and the prevalence of RLS migraine patients increased with increasing the research year, which was statistically significant (P < 0.05). Conclusion This study highlights that RLS is high in patients with migraine, and therefore, the clinicians should be aware of its incidence and take preventive measures.

Contrasting painless and painful phenotypes of pediatric restless legs syndrome: a twin family study

ObjectiveThis study was designed to investigate painless and painful subsets of pediatric restless legs syndrome (RLS) for genetic influence and for associations with iron deficiency and common pediatric pain disorders. MethodsIn a twin family study, twins (3–18 years) and their oldest siblings, mothers and fathers completed questionnaires, assessing lifetime prevalence of RLS using current criteria, as well as history of iron deficiency and pediatric pain disorders. Subsets were categorized as RLS-Painless or RLS-Painful. Within twin pair analyses were conducted to assess familial and potential genetic effects for the defined subsets. Penalized maximum likelihood logistic regression was used to test familial associations. Random-effects logistic regression modeling was used in the total pediatric sample to investigate univariate and multivariate associations with the subsets. ResultsData were available for 2033 twin individuals (1007 monozygous (MZ), 1026 dizygous (DZ); 51.7% female), 688 siblings, 1013 mothers and 921 fathers. Odds ratios, correlations and casewise concordance were significantly higher in MZ than in DZ twins only for RLS-Painful. RLS-Painless, though familial (co-twin and mother), was not genetically influenced, but was independently associated with female sex (OR 0.52, p = 0.003), iron deficiency (OR 4.20, p < 0.001) and with persistent pain disorders (OR 2.28, p = 0.02). RLS-Painful was familial and was probably genetically influenced; was independently associated with non-migraine headaches (OR 2.70, p = 0.02) and recurrent abdominal pain (OR 2.07, p = 0.04). ConclusionsPediatric RLS was heterogeneous and was categorized into contrasting painless and painful phenotypes. RLS-Painless was associated with iron deficiency while RLS-Painful accounted for the heritability of RLS.