Validation of the self-completed Cambridge-Hopkins questionnaire (CH-RLSq) for ascertainment of restless legs syndrome (RLS) in a population survey

A randomized double-blind pilot study to evaluate the efficacy, safety, and tolerability of intravenous iron versus oral iron for the treatment of restless legs syndrome in patients with iron deficiency anemia

Restless legs syndrome (RLS) is a neurological disorder that can have a profound effect on sleep and quality of life. Idiopathic RLS is associated with brain iron insufficiency despite normal peripheral iron stores. There is, however, a five- to six-fold increase in prevalence of RLS in patients with iron deficiency anemia (IDA). Several open-label trials have demonstrated symptomatic improvement in RLS following treatment of IDA using oral or intravenous iron supplementation. To date, there have been no randomized double-blind controlled trials of intravenous iron compared with oral iron for the treatment of RLS patients with IDA. In the current study, oral ferrous sulfate and ferumoxytol were compared for efficacy and speed of response for treatment of RLS occurring in patients with IDA. The planned recruitment for this study was 70 patients with RLS and IDA, to be randomly assigned 1:1 to oral or intravenous iron, using double-blind, double-dummy procedures. At Week 6, the primary outcomes of Clinical Global Impression-Improvement score and change from baseline in the International Restless Legs Syndrome Study Group rating scale score were assessed. Due to challenges, performing the clinical trial during the COVID-19 pandemic, final-week data were found missing for 30 patients. As a result, in order to maintain the prespecified statistical analysis, an additional 30 patients were recruited. Both IV and oral iron were associated with a marked improvement in RLS symptoms, with no statistically significant difference between treatment groups. No serious adverse events were observed in either treatment group.

Compromised Dynamic Cerebral Autoregulation in Patients with Restless Legs Syndrome

Background

Restless legs syndrome (RLS) is a prevalent sensorimotor nervous system disorder in patients accompanied with insomnia, blood pressure fluctuation, and sympathetic dysfunction. These symptoms may disrupt cerebral hemodynamics. Dynamic cerebral autoregulation (dCA) describes the temporary response of cerebrovascular system to abrupt fluctuations in blood pressure, which keep cerebral blood flow stable and serve as a marker of cerebrovascular system ability.

Objective

This research aimed to assess dCA in RLS patients.

Methods

In this study, RLS patients were recruited and subsequently classified into four groups (mild, moderate, severe, and very severe) based on the International RLS Rating Scale (IRLS). Healthy controls matched for age and sex were enrolled. All participants were evaluated dCA by assessing phase difference (PD). A portion of patients with RLS was reassessed for dCA after one month of medication therapy (pramipexole [0.125 mg/day] and gabapentin [300 mg/day]).

Results

There were altogether 120 patients with RLS and 30 controls completed the polysomnography and dCA assessment. PD was lower in the moderate, severe, and very severe RLS groups than that in the controls and mild RLS groups. Periodic limb movement index (PLMI), arousal index, and IRLS all showed a linear correlation with PD in RLS patients. Additionally, PD increased in RLS patients after therapy.

Conclusion

The dCA was compromised in moderate, severe, and very severe RLS patients and was negatively correlated with the IRLS, arousal index, and PLMI. After 1 month of therapy, dCA improved in RLS patients.

Brain Iron Dysregulation in Iron Deficiency Anemia-Related Restless Leg Syndrome Revealed by Neuron-Derived Extracellular Vesicles: A Case-Control Study

Brain iron deficiency (ID) and, to a degree, systemic ID have been implicated in restless leg syndrome (RLS) pathogenesis. Previously, we found increased ferritin in neuron-derived extracellular vesicles (NDEVs) in RLS, suggesting a mechanism for depleting intracellular iron by secreting ferritin-loaded NDEVs. In this study, we hypothesized that increased NDEV ferritin occurs even in RLS accompanied by systemic ID and that neuronal intracellular iron depletion in RLS also manifests as NDEV abnormalities in other iron regulatory proteins, specifically, decreased transferrin receptor (TfR) and increased ferroportin. To address these hypotheses, we studied 71 women with ID anemia, 36 with RLS, and 35 without RLS. Subjects with RLS again showed higher NDEV ferritin and also decreased TfR, suggesting diminished neuronal capacity for iron uptake. Findings inform a more complete understanding of the pathogenic role of neuronal iron homeostasis and dissociate it from peripheral ID. ANN NEUROL 2024.

Stakeholder involvement in the optimization of a patient-centered exercise intervention for people with restless legs syndrome

STUDY OBJECTIVES

Previous research supports exercise as a behavioral approach to manage symptoms of restless legs syndrome (RLS); however, completion rates in exercise studies are low. This study obtained key stakeholder feedback from people with RLS to modify and optimize a 12-week, evidence-based exercise program for RLS.

METHODS

Participants with RLS (n = 513) completed a nationwide survey to provide feedback on the necessity, interest, feasibility, and efficacy of the program as well as perceived barriers and proposed modifications to improve the exercise program.

RESULTS

Most respondents (67%) expressed the need for an exercise program designed specifically for people with RLS and 64% were interested in the program. Only 6% of participants thought the program would not be well tolerated and 6% responded that it would likely exacerbate symptoms. However, only 58% said they would be likely to participate in the program if it was available to them locally. Key barriers to participation were (1) accessibility, (2) personal factors, (3) trustworthiness, and (4) fear of injury, illness, or symptom exacerbations. Respondents highlighted modification considerations for the individualization of exercise features, adaptations for specific impairments/personal factors, inclusion of flexibility and balance exercises, and flexibility for more home-based activities.

CONCLUSIONS

Interest in the program was driven by the desire to reduce medications and improve overall quality of life. Appropriately educated and trained exercise providers knowledgeable about RLS are integral to buy-in from stakeholders. This study provides an imperative step in clinical research that can increase the success of subsequent implementation efforts and may accelerate the adoption of exercise programs into practice.

CITATION

Cederberg KLJ, Sikes EM, Mignot E. Stakeholder involvement in the optimization of a patient-centered exercise intervention for people with restless legs syndrome. J Clin Sleep Med. 2024;20(4):535-543.

Restless legs syndrome, periodic limb movements of sleep, and subclinical cardiovascular disease

Restless legs syndrome (RLS) and periodic limb movements of sleep (PLMS) have been variably implicated in risk for cardiovascular disease (CVD), but there is lack of consensus on these relationships. We sought to assess subclinical CVD measures and RLS/PLMS in a large cohort to further evaluate these associations. The Emory Center for Health Discovery and Well Being cohort is composed of employed adults, with subclinical CVD measures including endothelial function (flow-mediated vasodilation), microvascular function (reactive hyperemia index, RHI), arterial stiffness (pulse wave velocity and augmentation index), and carotid intima-media thickness (cIMT). Participants were grouped based on presence (N = 50) or absence (N = 376) of RLS and subclinical CVD measures compared between groups. A subset of participants (n = 40) underwent ambulatory monitoring for PLMS and obstructive sleep apnea. PLMS association with subclinical CVD measures was assessed. RLS status was significantly associated with flow-mediated dilation in univariate analyses but not after controlling for potential confounders; RLS was not associated with other subclinical CVD measures. PLMS were significantly correlated with the RHI, augmentation index, and cIMT in univariate analyses; only the association between PLMS and cIMT remained significant (p = 0.04) after controlling for RLS status, age, apnea-hypopnea index, hyperlipidemia, and hypertension. The observed association between higher PLMS and greater cIMT suggests that PLMS may be a marker of subclinical CVD. Further work is needed to determine the relationship between PLMS and CVD risk.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41105-023-00497-7.

The Melanocortin and Endorphin Neuropeptides in Patients with Restless Legs Syndrome

OBJECTIVE

Based upon similarities between the urge to move and sensory discomfort of restless legs syndrome (RLS) and properties of melanocortin hormones, including their incitement of movement and hyperalgesia, we assessed plasma and cerebrospinal fluid (CSF) α-melanocyte-stimulating hormone (α-MSH) and β-endorphin in RLS patients and controls.

METHODS

Forty-two untreated moderate-to-severe RLS patients and 44 matched controls underwent venipuncture at 19:00, 20:30, and 22:00; 37 RLS and 36 controls had lumbar puncture at 21:30. CSF and plasma were analyzed for pro-opiomelanocortin (POMC), adrenocorticotropin hormone (ACTH), α-MSH, β-MSH, and β-endorphin by immunoassay. RLS severity was assessed by International RLS Study Group Severity Scale.

RESULTS

RLS participants were 52.7 ± 12.0 years old, 61.9% were women, 21.4% had painful RLS, and RLS severity was 24.8 ± 9.0. Controls had similar age and sex. Plasma ACTH, α-MSH, and β-endorphin were similar between groups. Plasma POMC was significantly greater in RLS than controls (17.0 ± 11.5 vs 12.7 ± 6.1fmol/ml, p = 0.048). CSF ACTH was similar between groups. CSF β-MSH was significantly higher in painful than nonpainful RLS or controls (48.2 ± 24.8 vs 32.1 ± 14.8 vs 32.6 ± 15.2pg/ml, analysis of variance [ANOVA] p = 0.03). CSF α-MSH was higher in RLS than controls (34.2 ± 40.9 vs 20.3 ± 11.0pg/ml, p = 0.062). CSF β-EDP was lowest in painful RLS, intermediate in nonpainful RLS, and highest in controls (8.0 ± 3.4 vs 10.8 ± 3.1 vs 12.3 ± 5.0pg/ml, ANOVA p = 0.049). The ratio of the sum of CSF α- and β-MSH to CSF β-endorphin was highest, intermediate, and lowest in painful RLS, nonpainful RLS, and controls (p = 0.007).

INTERPRETATION

CSF β-MSH is increased and CSF β-endorphin decreased in RLS patients with painful symptoms. ANN NEUROL 2024;95:688-699.

Perceptions of exercise and restless legs syndrome: Results from a nationwide survey

Restless legs syndrome is a prevalent, sensorimotor sleep disorder temporarily relieved by movement, with evidence of symptomatic improvement with regular exercise. The present study describes perceptions of the effects of exercise on symptoms of restless legs syndrome. Participants (N = 528) completed a mixed-methods (i.e. numerical and narrative), nationwide survey including items assessing personal experiences with exercise and restless legs syndrome (both positive and negative), as well as restless legs syndrome diagnosis, restless legs syndrome severity, and demographic and clinical characteristics. Responses varied widely on specific experiences with exercise, but a higher percentage of participants indicated positive experiences with exercise than those who reported negative experiences (72%-40%, respectively) with exercise. Further, 54% of respondents reported that exercise only improves restless legs syndrome, while 24% reported exercise only worsens symptoms. Participants described that any abrupt change in exercise routine would almost always elicit restless legs syndrome symptoms (e.g. hiking for a long time, stopping an exercise routine), and that a consistent pattern of exercise improved restless legs syndrome symptoms with an overall beneficial effect on the frequency of symptomatic bouts. Participants further described time of day as impactful for their exercise experience, with > 50% indicating morning exercise improves symptoms and evening exercise worsens symptoms. Participants described several questions that they wanted answered regarding the evidence for exercise in restless legs syndrome and specific exercise prescription recommendations. The present study describes information crucial to the creation of stakeholder-informed health promotion programs for individuals with restless legs syndrome to optimize personalized treatment plans that could prevent and manage symptoms.

People with IBD evidence more microarousals during sleep architecture assessments

OBJECTIVE

Poor sleep is common in inflammatory bowel disease (IBD) and may be associated with overall worse disease outcomes. While the sleep/IBD literature is growing, the data are often self-reported. Further, much of the research using objective measures of sleep architecture, or the overall pattern of sleep depth, rely on single-night assessments, which can be of questionable validity.

DESIGN

Participants with IBD and healthy controls were recruited from Dartmouth-Hitchcock Medical Center as part of a two-phase clinical trial. Sleep architecture was assessed using three nights of in-home electroencephalographic monitoring and scored according to the American Academy of Sleep Medicine guidelines.

RESULTS

Our sample included 15 participants with IBD and 8 healthy controls. Participants with IBD were more psychiatrically complex, with more self-reported insomnia, anxiety and depression. Participants with IBD evidenced greater microarousals than healthy controls. In participants with IBD, microarousals were associated with lower insomnia and greater depression scores. Within IBD, participants with clinically significant insomnia evidenced trend towards lower sleep efficiency, while self-reported disease activity did not significantly impact findings.

CONCLUSIONS

The methodology of past research may have impacted findings, including the reliance on single-night assessments and limited generalisability. Future research that uses robust, multinight assessments of sleep architecture in large, diverse samples is clearly warranted, as is research exploring the impact of cognitive and behavioural factors on sleep architecture and arousal.

TRIAL REGISTRATION NUMBER

NCT04132024.

Prevalence of Current Restless Legs Syndrome Symptoms Among Patients Treated with Buprenorphine/Naloxone for Opioid Use Disorder

Objective

The purpose of this study was to determine the prevalence of Restless Legs Syndrome (RLS) in patients with Opioid Use Disorder (OUD) taking buprenorphine/naloxone maintenance therapy, and to assess symptom frequency, severity, and sleep disruption due to RLS.

Methods

Surveys inquired about demographic information, amount of time on maintenance treatment, previous drug use, current prescribed medications and alcohol use, and RLS symptoms. Participants were determined to have definite, probable, possible, or no RLS symptoms based on pre-established criteria from the Cambridge-Hopkins Questionnaire.

Results

The sample (n=129) was 33.3% female, 81.5% white, and the mean age was 40.6 years (SD=11.9). The median duration of buprenorphine/naloxone use was 3 years. 13.2% of participants had definite/probable RLS symptoms; these symptoms tended to be of moderate severity, occur at least 5-15 times a month, and disrupt sleep to a moderate degree. Of the 17 participants with definite/probable RLS symptoms, just four were taking a medication commonly used to alleviate RLS. An additional 7.0% had possible RLS symptoms.

Conclusion

Relatively high rates of current RLS symptoms were observed; the prevalence of clinically significant RLS was notably higher than that seen in the general population or in previously assessed clinical populations. RLS is common in those acutely withdrawing from opioids, and our data demonstrate that these symptoms are present in a sizable portion of patients on OUD maintenance therapy. Most patients with definite/probable current RLS symptoms did not report taking prescribed medications that have established efficacy for RLS.

Validation of an Arabic version of the Cambridge-Hopkins diagnostic questionnaire for restless legs syndrome

PURPOSE

To validate an Arabic version of the short form of the Cambridge-Hopkins diagnostic questionnaire for restless legs syndrome (CH-RLSq13).

METHODS

The Arabic version was created using a standard forward-backward translation method. A pre-final Arabic version was administered with the original English version to a group of bilingual subjects as a pretest. The inter-rater agreement between these two versions was measured. A finalized Arabic version was obtained. For the validation, the Arabic version of the CH-RLSq13 was administered to Lebanese subjects, above 18 years old, selected upon a clinical interview. The diagnosis provided by the Arabic version of the CH-RLSq13 was compared to the clinical diagnosis made by a neurologist at Hotel-Dieu de France hospital. Inter-rater agreement was assessed using Cohen's kappa coefficient. Sensitivity, specificity, and positive and negative predictive values of the translated questionnaire were calculated.

RESULTS

Inter-rater agreement, between the 2 versions, for the entire questionnaire, was excellent (κ = 0.950). All items showed a substantial level of agreement between the two versions. In the validation process, 91 participants were included (17 patients diagnosed with RLS and 74 control subjects). The mean age was 40 years, with female predominance. The final Arabic version of the CH-RLSq13 had a sensitivity of 71%, a specificity of 100%, and with negative and positive predictive values of 94% and 100% respectively.

CONCLUSION

The Arabic version of the CH-RLSq13 is a reliable tool for the screening and diagnosis of RLS in Lebanese and Arabic-speaking populations.

Modification and Validation of a Diagnostic Questionnaire for Restless Legs Syndrome: Modified-Restless Legs Syndrome Diagnostic Questionnaire (m-RLS-DQ)

Background

Diagnostic questionnaire that are available for restless legs syndrome does not include items related to RLS mimics and, hence, increases chances of false positive cases. This study aimed at modification and validation of RLS-diagnostic Questionnaire.

Methods

During modification, additional items were identified, developed, and subjected to evaluation by experts. Experts were requested to validate the content of each item. Based on their responses, content validity indices (average and universal agreement) were calculated. It was then translated to Hindi and validated in a clinical population that included patients with RLS, somatic symptoms disorder, anxiety, other RLS mimics, and osteoarthritis. In addition, a group of healthy controls was also included. Face, concurrent, and discriminant validities were calculated.

Results

Among 209 subjects, nearly 40 subjects had clinical diagnosis of RLS, osteoarthritis, somatic-symptoms-disorder, and anxiety disorder, each. In addition, 16 patients had other RLS mimics (akathisia, varicose veins, BFS, leg-cramps, chronic insomnia) and 30 were healthy controls. After multiple revisions, content validity indices achieved a score of 1 for m-RLS-DQ. Sensitivity and specificity of m-RLS-DQ v. 1.4 for the diagnosis of RLS were 94.9% and 94.1%, respectively. For the diagnosis of RLS, PPV was 78.7%, and NPV was 98.7% with an accuracy of 94.3%. Less than one fourth of participants having chronic insomnia, somatic symptoms disorder, anxiety disorder, and knee osteoarthritis were found to be false positive on m-RLS-DQ; however, none of the healthy controls were found positive on m-RLS-DQ. Concurrent validity with clinical diagnosis of RLS was 0.83 (P < 0.001). Discriminant validity with somatic symptoms disorder was -0.14 (P = 0.03) and with osteoarthritis -0.24 (P < 0.001).

Conclusion

m-RLS-DQ is a valid instrument with acceptable psychometric properties, which can be used for the screening as well as diagnosis of RLS in clinical practice and research studies.

Emergence of restless legs syndrome during opioid discontinuation

STUDY OBJECTIVES

The development of restless legs syndrome (RLS) has been rarely reported during and following opioid withdrawal. We aimed to determine the presence and severity of RLS symptoms during and after supervised opioid tapering.

METHODS

Ninety-seven adults enrolled in the Mayo Clinic Pain Rehabilitation Center who underwent supervised prescription opioid tapering were prospectively recruited. RLS presence and severity was assessed with the Cambridge-Hopkins Questionnaire 13 and International Restless Legs Syndrome Study Group Rating Severity Scale at admission, midpoint, and dismissal from the program as well as 2 weeks, 4 weeks, and 3 months after completion. Frequency and severity of RLS symptoms were compared between admission and each time point.

RESULTS

Average age of the cohort was 52.6 ± 13.3 years with a morphine milligram equivalent dose for the cohort of 45.6 ± 48.3 mg. Frequency of RLS symptoms increased from 28% at admission to peak frequency of 41% at 2 weeks following discharge from the Mayo Pain Rehabilitation Clinic (P = .01), returning to near baseline frequency 3 months after opioid discontinuation. International Restless Legs Syndrome Study Group Rating Severity Scale increased from baseline and then remained relatively stable at each time point following admission. Thirty-five (36.1%) participants developed de novo symptoms of RLS during their opioid taper, with those being exposed to higher morphine milligram equivalent doses having higher risk of developing RLS.

CONCLUSIONS

Moderately severe symptoms of RLS, as assessed by survey, occur commonly in individuals undergoing opioid tapering, particularly if exposed to higher doses. In many cases, symptoms appear to be self-limited, although a minority develop persistent symptoms. Our results may have implications for successful opioid tapering, but future confirmatory studies with structured clinician interview are needed to establish that these symptoms truly represent restless legs syndrome given the potential for RLS-mimicking symptoms in individuals with chronic pain syndromes.

CITATION

McCarter SJ, Labott JR, Mazumder MK, et al. Emergence of restless legs syndrome during opioid discontinuation. J Clin Sleep Med. 2023;19(4):741-748.

Restless Legs Syndrome and Periodic Limb Movements of Sleep: From Neurophysiology to Clinical Practice

SUMMARY

This article summarizes restless legs syndrome (RLS), periodic limb movements of sleep, and periodic limb movement disorder. RLS is a common sleep disorder with a prevalence of 5% to 15% in the general population. RLS can present in childhood, and incidence increases with age. RLS can be idiopathic or secondary to iron deficiency, chronic renal failure, peripheral neuropathy, and medications such as antidepressants (with higher rates for mirtazapine and venlafaxine, while bupropion may reduce symptoms at least in the short term), dopamine antagonists (neuroleptic antipsychotic agents and antinausea medications), and possibly antihistamines. Management includes pharmacologic agents (dopaminergic agents, alpha-2 delta calcium channel ligands, opioids, benzodiazepines) and nonpharmacologic therapies (iron supplementation, behavioral management). Periodic limb movements of sleep are an electrophysiologic finding commonly accompanying RLS. On the other hand, most individuals with periodic limb movements of sleep do not have RLS. The clinical significance of the movements has been argued. Periodic limb movement disorder is a distinct sleep disorder that arises in individuals without RLS and is a diagnosis of exclusion.

Attention deficit hyperactivity disorder and restless leg syndrome across the lifespan: A systematic review and meta-analysis

This systematic review aims to assess the association between attention deficit hyperactivity disorder (ADHD) and restless legs syndrome (RLS) in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Databases were searched for original articles that reported prevalence data on ADHD and RLS until January 24th, 2023. Two independent reviewers evaluated the quality of the articles using the National Institutes of Health assessment tool. Among the 208 articles identified between 1996 and 2022, 29 were included. In large general population studies, 2.6-15.3% of participants met the RLS criteria, of which 3.2-17.4% presented with ADHD. In the ADHD group, RLS symptoms ranged from 11 to 42.9% in children and 20-33.0% in adults. This suggests a strong co-occurrence between RLS and ADHD. A common characteristic of these conditions is sleep fragmentation, as discussed in the reviewed papers. Although large-scale studies with comparable diagnostic criteria across the lifespan are required, our findings may advocate a possible common physiological pathway, including sleep fragmentation and dopaminergic system impairment.

Adverse childhood experiences and sleep links in a predominantly Black sample of overweight adults

Adverse childhood experiences (ACEs) have been associated with worse sleep, but existing literature is limited by use of predominantly White samples, lack of objective sleep measurement, and use of non-standardized questionnaires. We investigated associations between retrospectively reported ACEs and sleep in adulthood in a sample of 43 adults 20-53 years of age, free from chronic conditions, with a Body mass index (BMI) ≥ 25 (Mean age = 33.14 [SD = 10.05], 74% female, 54% Black). Sleep efficiency (SE), total sleep time (TST), wake after sleep onset (WASO), and sleep onset latency (SOL), were measured by actigraphy and daily diary. Global sleep quality and insomnia severity were measured by questionnaires. Sleepiness, fatigue, and sleep quality were also measured by daily diary. Adjusting for demographic characteristics and BMI, ACEs were significantly associated with poorer global sleep quality and diary measures of greater daytime sleepiness, fatigue, and poorer sleep quality. There were no significant associations between ACEs and SE, TST, WASO, or SOL measured by diary or actigraphy. Findings suggest that ACEs are associated with worse sleep perception and daytime functioning in adulthood. Larger prospective studies are needed to replicate these findings, examine racial/ethnic differences, and determine temporal associations between ACEs, sleep, and health (e.g., BMI).

Sleep state of the elderly population in Korea: Nationwide cross-sectional population-based study

Objective

Interest in sleep disorders among the elderly, especially those in Korea, has increased. We aimed to describe the overall sleep status of the elderly population in Korea using survey data and to determine the risk factors concerning different aspects of sleep status.

Methods

We conducted a cross-sectional survey on 271 respondents aged 65-86 years old. We performed multistage clustered random sampling according to the population and socioeconomic distribution of all Korean territories. The survey questionnaire was used to perform a structural assessment of sociodemographic characteristics; medical comorbidities; psychiatric comorbidities; and sleep status, including sleep duration, sleep quality, presence of insomnia, excessive daytime sleepiness, sleep apnea, and restless legs syndrome.

Results

Approximately 12.5, 22.%, and 51.3% of the elderly population had poor sleep quality, excessive daytime sleepiness, and insomnia, respectively. Hypertension, dyslipidemia, insomnia, anxiety, and depression predicted poor sleep quality. Female sex, insomnia, and sleep apnea predicted excessive daytime sleepiness. Poor sleep quality and depression predicted insomnia.

Conclusion

A substantial proportion of the elderly Korean population have sleep problems, including poor sleep quality, excessive daytime sleepiness, and insomnia. Sleep status is influenced by various factors, including age, sex, and metabolic and psychiatric comorbidities.

Determination of optimal 25-hydroxyvitamin D cutoff values for the evaluation of restless legs syndrome among pregnant women

STUDY OBJECTIVES

Vitamin D deficiency is associated with restless legs syndrome (RLS). However, a cutoff value for serum 25-hydroxyvitamin D (25[OH]D) level associated with RLS has yet to be clearly determined. We evaluated the association between 25(OH)D and RLS in pregnant women.

METHODS

Data from 203 pregnant women were evaluated using blood samples taken in the third trimester. Liquid chromatography-tandem mass spectrometry and ligand binding assays were used to measure 25(OH)D. RLS was diagnosed based on International Classification of Sleep Disorders, third edition, criteria. The cutoff value for serum 25(OH)D associated with RLS was explored using receiver operating characteristic (ROC) curve and classification and regression tree (CART) analyses.

RESULTS

The results of liquid chromatography-tandem mass spectrometry (x) and ligand binding assays (y) for serum 25(OH)D in the RLS (n = 35, 17.2%) and non-RLS (n = 168) groups showed a relationship of y = -2.65 + 0.08x . The RLS group showed lower serum 25(OH)D and folate levels. ROC curve and CART analyses revealed cutoff values of 10-12.7 ng/mL and 6.6-7.2 ng/mL for 25(OH)D and folate, respectively. Of the 5 women with RLS symptoms persisting at a moderate-to-severe level after delivery, 4 had 25(OH)D levels < 10 ng/mL and all had folate levels < 6 ng/mL.

CONCLUSIONS

Vitamin D and folate deficiency were associated with RLS in pregnant women and may be associated with persistent moderate-to-severe postpartum RLS symptomatology; it is essential to examine associations with RLS while accounting for measurement methods and assay systems.

CITATION

Miyazaki A, Takahashi M, Shuo T, Eto H, Kondo H. Determination of optimal 25-hydroxyvitamin D cutoff values for the evaluation of restless legs syndrome among pregnant women. J Clin Sleep Med. 2023;19(1):73-83.

Does physical activity timing differentially correlate with symptoms of restless legs syndrome in adults with multiple sclerosis?

OBJECTIVE/BACKGROUND

The present study examined the associations among physical activity during different times of the day(i.e., morning, midday,evening) and days of the week(i.e., weekdays, weekend days) with restless legs syndrome(RLS) severity and sleep quality in adults with multiple sclerosis(MS).

PATIENTS/METHODS

Participants(N = 39) completed the International Restless Legs Syndrome Study Group Scale and the Pittsburgh Sleep Quality Index as measures of RLS severity and global sleep quality, respectively, and wore an ActiGraph GT3X + on the non-dominant hip for seven days for measuring physical activity(i.e., light physical activity[LPA], moderate-to-vigorous physical activity[MVPA], and steps).

RESULTS

There was a significant effect of time of day wherein participants had more midday activity compared with morning or evening for LPA, MVPA, and steps; there was no effect of day of the week. Spearman's rho correlations across the week indicated higher evening LPA, evening steps, and overall daily steps (ρ = -0.42,ρ = -0.51,ρ = -0.40,respectively) were associated with lower RLS severity. Similar associations were demonstrated for weekdays(ρ = -0.39,ρ = -0.50,ρ = -0.41,respectively) and weekend days(ρ = -0.44,ρ = -0.51,ρ = -0.39,respectively). Higher evening MVPA on weekend days(ρ = -0.42) was associated with lower RLS severity. Higher morning and overall daily LPA(ρ = 0.34,ρ = 0.33,respecitvely) were associated with worse sleep quality. Similar associations were demonstrated on weekdays(ρ = 0.33,ρ = 0.37,respectively) and more evening MVPA(ρ = 0.32) was associated with worse sleep quality. On weekend days, more morning MVPA(ρ = 0.42) was associated with worse sleep quality.

CONCLUSIONS

Our results suggest that undertaking physical activity, particularly LPA and steps, in evenings may be important for managing symptoms of RLS without worsening sleep quality.

Restless legs syndrome severity associated with reduced physical function in adults with multiple sclerosis

BACKGROUND

Restless legs syndrome (RLS) is a sleep disorder that occurs in approximately 26 % of adults with multiple sclerosis (MS) and may be associated with reduced physical function.

RESEARCH QUESTION

The present study examined the relationship between RLS symptomology (i.e., overall severity, frequency, and occurrence) and physical function outcomes in adults with MS who had RLS.

METHODS

Participants (N = 22) with MS who had RLS came into the laboratory for a single session wherein a rater performed a brief neurological examination for scoring the Expanded Disability Status Scale (EDSS) and completed a demographics questionnaire, the International Restless Legs Syndrome Study Group Scale (IRLS), and the Restless Legs Syndrome Scale-6 (RLS-6) followed by the Short Physical Performance Battery (SPPB) and the Six-minute Walk Test (6 MW).

RESULTS

Bivariate Spearman's rho correlation analyses indicated total IRLS had a strong, negative association with total distance traveled during the 6 MW (ρ = -0.50) and a moderate association with SPPB scores (ρ = -0.43), but not EDSS scores (ρ = 0.28). RLS severity during the day while active had strong, negative associations with total distance traveled during the 6 MW (ρ = -0.61) and SPPB scores (ρ = -0.52), but not EDSS scores (ρ = 0.13).

SIGNIFICANCE

We observed associations between worse overall RLS severity and RLS severity during the day while active with reduced performance during the 6 MW and lower SPPB scores. The management of RLS may offer an opportunity for mitigating reductions in physical function in adults with MS who have RLS.

Constructing prediction models for excessive daytime sleepiness by nomogram and machine learning: A large Chinese multicenter cohort study

Objective

Although risk factors for excessive daytime sleepiness (EDS) have been reported, there are still few cohort-based predictive models for EDS in Parkinson’s disease (PD). This 1-year longitudinal study aimed to develop a predictive model of EDS in patients with PD using a nomogram and machine learning (ML).

Materials and methods

A total of 995 patients with PD without EDS were included, and clinical data during the baseline period were recorded, which included basic information as well as motor and non-motor symptoms. One year later, the presence of EDS in this population was re-evaluated. First, the baseline characteristics of patients with PD with or without EDS were analyzed. Furthermore, a Cox proportional risk regression model and XGBoost ML were used to construct a prediction model of EDS in PD.

Results

At the 1-year follow-up, EDS occurred in 260 of 995 patients with PD (26.13%). Baseline features analysis showed that EDS correlated significantly with age, age of onset (AOO), hypertension, freezing of gait (FOG). In the Cox proportional risk regression model, we included high body mass index (BMI), late AOO, low motor score on the 39-item Parkinson’s Disease Questionnaire (PDQ-39), low orientation score on the Mini-Mental State Examination (MMSE), and absence of FOG. Kaplan–Meier survival curves showed that the survival prognosis of patients with PD in the high-risk group was significantly worse than that in the low-risk group. XGBoost demonstrated that BMI, AOO, PDQ-39 motor score, MMSE orientation score, and FOG contributed to the model to different degrees, in decreasing order of importance, and the overall accuracy of the model was 71.86% after testing.

Conclusion

In this study, we showed that risk factors for EDS in patients with PD include high BMI, late AOO, a low motor score of PDQ-39, low orientation score of MMSE, and lack of FOG, and their importance decreased in turn. Our model can predict EDS in PD with relative effectivity and accuracy.

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.

Poor Sleep in Inflammatory Bowel Disease Is Reflective of Distinct Sleep Disorders

BACKGROUND

Poor sleep is common in inflammatory bowel disease (IBD), predicting increased risk of flares, surgery, and/or hospitalization and reducing quality of life.

AIMS

To profile specific sleep disorder symptoms in IBD, informing intervention efforts.

METHODS

312 adults with Crohn's disease or ulcerative colitis were recruited from an academic medical center in New Hampshire, USA. Participants completed online surveys about sleep including well-validated measures of sleep quality, insomnia, restless leg syndrome, sleep apnea, and circadian rhythms. Participants also answered questions about IBD-related problems that could interfere with sleep.

RESULTS

69.4% of participants reported experiencing poor sleep and 50% reported clinically significant insomnia. Participants with active IBD symptoms were more likely to have poor sleep and insomnia. Of those with poor sleep, 67.8% met the clinical threshold for insomnia disorder and 31.3% met criteria for two or more sleep disorders. IBD-related sleep disruptions (e.g., nighttime awakenings due to bowel movements) were not significantly related to poor sleep quality, but significantly related to insomnia severity for participants with active Crohn's disease.

CONCLUSIONS

While poor sleep in IBD is reflective of a number of different sleep problems, it is most frequently related to insomnia. IBD symptom severity contributes to insomnia, but insomnia is also distinct from IBD-related sleep disruptions. Future research on the treatment of insomnia disorder in particular in individuals with IBD is warranted.

Demographic, clinical, and biochemical predictors of pica in high-intensity blood donors

BACKGROUND

Frequent blood donors who contribute multiple times annually are important for maintaining an adequate blood supply. However, repeated donations exacerbate iron deficiency, which can lead to pica, a condition characterised as repeated eating or chewing of a non-nutritious substance such as ice, clay and dirt. Understanding characteristics of frequent donors that are associated with increased risk for developing pica will help to identify them and prevent this adverse consequence of blood donation.

METHODS

Demographic, clinical, haematological, and biochemical factors associated with pica were investigated using univariable and multivariable logistic regression analysis in a cohort of 1693 high-intensity donors who gave nine or more units of whole blood in the preceding 2 years. Pica was classified by questionnaire responses as consuming at least 8 oz of ice daily and/or consumption of non-ice substances regardless of the amount and frequency.

RESULTS

Pica was present in 1.5% of the high-intensity donors, and only occurred in those with ferritin <50 ng/ml. Of 16 candidate variables, only haematocrit (OR = 0.835, p = 0.020) was independently associated with pica. Although severe iron deficiency was more prevalent in high-intensity donors, pica behaviours were less prevalent than in less frequent donors (2.2%).

CONCLUSION

We have uncovered predictors of pica in high-intensity donors, which further emphasises the need to continue to implement iron replacement programs to reduce the prevalence of pica and maintain a robust pool of frequent donors.

Validation and Diagnostic Accuracy of Hindi Restless Legs Syndrome (RLS-H) Screening Tool

Background  Restless legs syndrome (RLS), a prevalent and treatable entity, has high impact on quality of life, requiring a better screening tool for its early detection. Thus, present study aimed to derive a Hindi RLS (RLS-H) screening tool for its use in Indian population.

Materials and Methods  RLS-H screening tool, derived by translating first four criteria of 2012 revised International Restless Legs Syndrome Study Group (IRLSSG) diagnostic criteria in Hindi and was validated in 50 RLS and 50 non-RLS patients. This validated RLS-H tool was used to screen 1,066 patients attending neurology clinic for assessing its diagnostic accuracy. Internal consistency, discriminatory validity, and various diagnostic yields were calculated. IRLSSG was used as gold standard for final diagnosis of RLS.

Results  RLS-H screening tool had an internal consistency of 0.910. No correlation was found between RLS-H screening tool and Epworth sleepiness scale, Pittsburgh sleep quality index, or International Restless Legs Syndrome Study Group rating scale indicating satisfactory discriminant validity. Prevalence of RLS was 13.6%. The question (Q)1 had highest sensitivity (97.9%) and Q4 had highest specificity (92.66%). Thus, its combinations (Q1 + Q4) along with addition of Q2 or Q3 were compared for best combination of diagnostic accuracy. A minimum cutoff value of RLS-H screening tool was 2.5 for considering patients requiring detailed RLS evaluation.

Conclusion  RLS-H screening tool can be used as a screening tool for early detection of RLS among susceptible patients. Patients answering “yes” to more than two questions (cutoff = 2.5) or “yes” to Q1 and Q4 should be interviewed and assessed for RLS.

Ferritin-guided iron supplementation in whole blood donors: optimal dosage, donor response, return and efficacy (FORTE)-a randomised controlled trial protocol

BACKGROUND

Frequent whole blood donors have an increased risk of developing iron deficiency. Iron deficiency can have detrimental health effects when left untreated. Donation intervals are commonly too short to replenish iron stores and extending these reduces donor availability. Oral iron supplementation is known to shorten iron store recovery time but may also induce gastrointestinal complaints. We aim to optimise the effectiveness of iron supplements while minimising the risks of side effects. Therefore, we will evaluate the impact of different iron supplementation protocols in terms of dosage and frequency on ferritin and haemoglobin levels, gastrointestinal side effects, iron deficiency-related symptoms and donor return compared with placebo supplementation.

METHODS

Twelve hundred whole blood donors with ferritin levels ≤30 µg/L are included into a double-blind, randomised controlled trial. Participants are randomly allocated to one of six arms, administering capsules containing 0 mg, 30 mg or 60 mg of iron, either on alternate days or daily for 56 days. At baseline and 56, 122 and 182 days of follow-up, ferritin and haemoglobin levels are measured, and compliance, donor return, dietary iron intake, gastrointestinal, iron deficiency-related symptoms and general health are assessed by questionnaire.

ETHICS AND DISSEMINATION

This study will provide a comprehensive overview of the effects of different frequencies and dosages of administration of iron supplements on iron status and health effects, thereby considering individual differences in treatment adherence and lifestyle. The outcome will provide scientific evidence to guide the debate if and how oral iron supplements may support the recovery of whole blood donors with low ferritin levels.

TRIAL REGISTRATION NUMBER

NL8590; The Dutch trial registry.

Discrepancies between self-reported and device-measured sleep parameters in adults with multiple sclerosis

STUDY OBJECTIVES

Sleep problems are a common consequence of multiple sclerosis; however, there is limited evidence regarding the agreement between device-measured and self-reported sleep parameters in adults with multiple sclerosis. The present study examined the agreement between self-reported and device-measured parameters of sleep quality in a sample of adults with multiple sclerosis.

METHODS

Participants (n = 49) completed a 7-day sleep diary and wore a wrist-worn ActiGraph GT3×+ (ActiGraph Corp., Pensecola, FL) for seven consecutive nights to quantify self-reported and device-measured sleep parameters, respectively.

RESULTS

There was a significant discrepancy between self-reported and device-measured parameters of total time in bed (mean difference = 19.8 [51.3] min), sleep onset latency (mean difference = 22.2 [19.5] min), and frequency of awakenings during the night (mean difference = 12.8 [6.8]). Intraclass correlation estimates indicated poor agreement between methods on most parameters, except for total time in bed (intraclass correlation = 0.80). Bland-Altman plots suggested that total time in bed and total sleep time had acceptable levels of agreement and linear regression analyses indicated that sleep onset latency (F = 113.91, B = -1.34, P < .001), number of awakenings (F = 543.34, B = 1.85, P < .001), and sleep efficiency (F = 18.39, B = -0.77, P < .001) had significant proportional bias.

CONCLUSIONS

Our results draw attention to the discrepancies between sleep parameter measurements and highlight the importance of including both self-report and device-measured outcomes for a complete and accurate representation of sleep in adults with multiple sclerosis.

CITATION

Cederberg KLJ, Mathison BG, Schuetz ML, Motl RW. Discrepancies between self-reported and device-measured sleep parameters in adults with multiple sclerosis. J Clin Sleep Med. 2022;18(2):415-421.

Restless legs syndrome is associated with long-COVID in women

STUDY OBJECTIVES

Sleep disturbance is common in long-COVID (LC). Restless legs syndrome (RLS) is characterized by sleep disturbance and has been reported after viral infections. Therefore, we evaluated RLS symptoms cross-sectionally in individuals with LC at both current and pre-coronavirus disease 2019 (pre-COVID-19) time points.

METHODS

Adults on LC-focused Facebook pages were recruited for an online assessment of symptoms before COVID-19 infection and during their present LC state in a cross-sectional manner. The LC group documented baseline symptoms retrospectively. Questions were included about the presence/severity of RLS symptoms and assessments of fatigue, quality of life, and sleep apnea. A control group was recruited and included individuals ≥ 18 years of age who never had overt symptoms of COVID-19. Pregnancy was an exclusion criterion for both groups.

RESULTS

There were 136 participants with LC (89.7% females, age 46.9 ± 12.9 years) and 136 controls (65.4% females, age 49.2 ± 15.5). RLS prevalence in females with LC was 5.7% pre-COVID-19 and 14.8% post-COVID-19 (P < .01) vs 6.7% in control females. Severity of RLS was moderate in both groups. Logistic regression predicting post-COVID-19 RLS among females with LC failed to find significant effects of hospitalization, sleep apnea, neuropathic pain severity, or use of antihistamines and antidepressants.

CONCLUSIONS

The baseline prevalence of RLS in females with LC was similar to the general population group as well as to patients in epidemiological studies. The prevalence significantly increased in the LC state. Postinfectious immunological mechanisms may be at play in the production for RLS symptoms.

CITATION

Weinstock LB, Brook JB, Walters AS, Goris A, Afrin LB, Molderings GJ. Restless legs syndrome is associated with long-COVID in women. J Clin Sleep Med. 2022;18(5):1413-1418.

Restless Legs Symptoms and Periodic Leg Movements in Sleep Among Patients with Parkinson's Disease

BACKGROUND

The association between restless legs syndrome (RLS) and Parkinson's disease (PD) remains controversial, with epidemiologic and descriptive evidence suggesting some potential overlap while mechanistic/genetic studies suggesting relative independence of the conditions.

OBJECTIVE

To examine a known, objectively measured endophenotype for RLS, periodic leg movements (PLMS) in sleep, in patients with PD and relate that objective finding to restless legs symptoms.

METHODS

We performed polysomnography for one (n = 8) or two (n = 67) consecutive nights in 75 PD patients and examined the association of PLMS with restless legs symptoms.

RESULTS

We found no association between restless legs symptoms and PLMS in PD. Prevalence of both was similar to data reported previously in other PD samples.

CONCLUSION

We interpret these results as suggesting that restless legs symptoms in PD patients may represent a different phenomenon and pathophysiology than RLS in the non-PD population.

Associations Between Self-Reported Sleep Disturbances and Cognitive Impairment: A Population-Based Cross-Sectional Study

OBJECTIVE

Cognitive impairment is a rapidly growing global public health problem in China and worldwide. In the recent decades, emerging studies have explored the associations between sleep disturbances and cognitive impairment. However, the variety of the results imply us that further studies should be conducted for the associations.

METHODS

This is a cross-sectional study conducted between August and October 2018 in five cities in Hebei province, China. Subjects were 21,376 community residents. Cognitive impairment was screened by the Chinese version of the Mini-Mental State Examination (MMSE). Scales of Athens Insomnia Scale (AIS), Berlin Questionnaire (BQ), REM (rapid eye movement) Sleep Behavior Disorder Questionnaire (RBDQ-HK), Ullanlinna Narcolepsy Scale (CUNS), and Cambridge-Hopkins Restless Legs Syndrome Questionnaire (CH-RLSq) were used to access insomnia, sleep apnea, REM sleep behavior disorder, narcolepsy, and restless leg syndrome.

RESULTS

The mean ± SD (standard error) of MMSE, AIS, RBDQ-HK, and CUNS were 27.95 ± 4.79, 2.16 ± 3.39, 5.55 ± 7.75, and 3.76 ± 2.31, respectively. Among the participants, 10.6% and 1.5% of the participants were identified as having a high risk of sleep apnea and restless leg syndrome, respectively. The results of multiple linear regression showed that cognitive impairment was associated with insomnia (β = -0.037, p < 0.001) and narcolepsy (β = -0.023, p < 0.001). The association between sleep apnea (β = -0.002, p > 0.05), REM sleep behavior disorder (β = 0.006, p > 0.05), restless leg syndrome (β = -0.007, p > 0.05), and cognitive impairment were not supported. Other factors associated with cognitive impairment were gender, age, education level, married status, and region.

CONCLUSION

This study provides some epidemiological evidence for the association between sleep disturbances and cognitive impairment among community residents in central China. In this study, the associations between insomnia, narcolepsy, and cognitive impairment were identified, but the associations between sleep apnea, REM sleep behavior disorder, narcolepsy, restless leg syndrome, and cognitive impairment were not supported among community residents.

Characteristics of Autonomic Dysfunction in Parkinson's Disease: A Large Chinese Multicenter Cohort Study

Autonomic dysfunction (AutD) is one of the non-motor symptoms (NMSs) in Parkinson's disease (PD). To investigate the prevalence and clinical features of AutD in Chinese patients with PD, a large multicenter cohort of 2,556 individuals with PD were consecutively involved in the Parkinson's Disease and Movement Disorders Multicenter Database and Collaborative Network in China (PD-MDCNC) between January 1, 2017, and December 31, 2019. The assessment of AutD was performed using the Scale for Outcomes in Parkinson's Disease for Autonomic Symptoms (SCOPA-AUT). The evaluation of motor symptoms and other NMSs were performed using well-established scales recommended by the Movement Disorder Society. We found that out of 2,556 patients with PD, 2,333 patients with PD (91.28%) had AutD. Compared with the group of patients with PD without AutD, the group of patients with PD with AutD had older age, older age of onset, longer disease duration, more severe motor symptoms, motor complications, and more frequent NMSs. As for partial correlation analysis, the total SCOPA-AUT score was significantly and positively associated with motor severity scales [Unified Parkinson's Disease Rating Scale (UPDRS) total score] and some of the NMSs [Rapid Eye Movement Sleep Behavior Disorder Questionnaire (RBD), Epworth Sleepiness Scale, Hamilton Depression Scale], Fatigue Severity Scale, and Parkinson's disease questionnaire. PD Sleep Scale was significantly and negatively correlated with AutD. With logistic regression analysis for potentially related factors, age, UPDRS total score, RBD, hyposmia, depression, and fatigue may be associated with PD with AutD. In conclusion, our multicenter cohort study reported the high prevalence of AutD in Chinese PD and revealed the associated factors of PD with AutD.

Restless Legs Syndrome Severity and Cognitive Function in Adults with Multiple Sclerosis: An Exploratory Pilot Study

Background:

Restless legs syndrome (RLS) is a sleep disorder present in as many as 26% of persons with multiple sclerosis (MS) and can be associated with cognitive function. The present study examined the relationships between RLS symptoms (severity, frequency, occurrence) and cognitive function in adults with MS who have RLS.

Methods:

Twenty-two participants attended one laboratory session and completed the International Restless Legs Syndrome Study Group Rating Scale (IRLS), the Restless Legs Syndrome-6 Scale (RLS-6), and then the Brief International Cognitive Assessment for Multiple Sclerosis battery consisting of the Symbol Digit Modalities Test; California Verbal Learning Test, Second Edition; and Brief Visuospatial Memory Test–Revised.

Results:

Nonparametric bivariate correlations indicated that worse IRLS total severity was associated with slower processing speed (ρ = −0.42), worse verbal memory (ρ = −0.63), and worse visual memory (ρ = −0.61); worse RLS severity at falling asleep was associated with worse verbal memory (ρ = −0.45) and worse visual memory (ρ = −0.55); and worse RLS severity during the day while active was associated with slower processing speed (ρ = −0.58), worse verbal memory (ρ = −0.52), and worse visual memory (ρ = −0.60).

Conclusions:

These results suggest that those with more severe RLS, including worse symptoms at falling asleep and during the day while active, might experience worse cognitive function, particularly processing speed and memory. Future research should evaluate whether treatment of RLS symptoms can offer new opportunities for managing cognitive dysfunction in adults with MS.

No association between plasma hepcidin levels and restless legs syndrome - results from the Danish Blood Donor Study

BACKGROUND

Restless Legs Syndrome (RLS) is a neurological sensorimotor disorder that occurs in the evening and night, thereby often impacting quality of sleep in sufferers. The aetiology of RLS is not completely understood although iron dysregulation has been suggested as a likely pathway. The relationship between RLS and the iron regulatory protein hepcidin has not been studied in large cohorts. We aimed to assess whether an association between plasma hepcidin variation and RLS exists in a large cohort of healthy individuals.

METHODS

Plasma hepcidin levels were measured in 9708 Danish blood donors from the Danish Blood Donor Study all of whom correctly completed the validated Cambridge-Hopkins RLS-questionnaire for RLS assessment.

RESULTS

A total of 466 blood donors were determined as current RLS cases in the sample (4.8%). RLS cases had a significantly higher proportion of females (56.7% vs 46.7%; P < 0.001) and were older (median age [IQR] 40.6 years vs 38.0 years; P = 0.010) than controls. RLS cases were also more frequent smokers (P = 0.004). No significant differences were found in body mass index (BMI), alcohol consumption, time of donation and donation history between cases and controls. No difference in plasma hepcidin levels was observed between RLS cases and controls (median concentration [IQR]: 10.5 ng/ml [6.3-16.4] in RLS cases vs 10.5 ng/ml [6.0-16.5] in controls). Using a logistic regression model, we found that hepcidin levels were not associated with RLS after adjusting for age, sex, alcohol consumption, smoking status, donation time and donation history (OR = 1.00 [0.99-1.02] per 1 ng/ml increase of hepcidin; P = 0.429).

CONCLUSION

Our study in Danish blood donors did not find an association between RLS and plasma hepcidin levels. Our findings suggest that plasma hepcidin's role as a potential diagnostic biomarker of RLS is inadequate.

Prevalence and correlates of restless legs syndrome in men living with HIV

Background

Data on the prevalence and correlates of restless legs syndrome (RLS) in people with HIV are limited. This study sought to determine the prevalence of RLS, associated clinical correlates, and characterize sleep-related differences in men with and without HIV.

Methods

Sleep-related data were collected in men who have sex with men participating in the Multicenter AIDS Cohort Study (MACS). Demographic, health behaviors, HIV status, comorbidities, and serological data were obtained from the MACS visit coinciding with sleep assessments. Participants completed questionnaires, home polysomnography, and wrist actigraphy. RLS status was determined with the Cambridge-Hopkins RLS questionnaire. RLS prevalence was compared in men with and without HIV. Multinomial logistic regression was used to examine correlates of RLS among all participants and men with HIV alone. Sleep-related differences were examined in men with and without HIV by RLS status.

Results

The sample consisted of 942 men (56% HIV+; mean age 57 years; 69% white). The prevalence of definite RLS was comparable in men with and without HIV (9.1% vs 8.7%). In multinomial regression, HIV status was not associated with RLS prevalence. However, white race, anemia, depression, and antidepressant use were each independently associated with RLS. HIV disease duration was also associated with RLS. Men with HIV and RLS reported poorer sleep quality, greater sleepiness, and had worse objective sleep efficiency/fragmentation than men without HIV/RLS.

Conclusions

The prevalence of RLS in men with and without HIV was similar. Screening for RLS may be considered among people with HIV with insomnia and with long-standing disease.

Demographic, clinical, and biochemical predictors of pica in a large cohort of blood donors

BACKGROUND

Pica is characterized as repeatedly eating or chewing a non-nutritious substance including, but not limited to ice, clay and dirt, starch, raw pasta, chalk, coal, paint, or paper. Pica symptoms can be intense and addiction-like and disrupt quality of life. It is strongly linked to iron deficiency. Since substantial iron loss occurs during blood donation, blood donors may be susceptible to development of pica behaviors.

METHODS

We investigated demographic, clinical, hematological, and biochemical factors associated with pica using univariable and multivariable logistic regression analysis in a cohort of 11,418 racially diverse blood donors. Pica was defined by questionnaire responses as consuming at least 8 oz of ice daily and/or consumption of non-ice substances regardless of the amount and frequency.

RESULTS

Pica was present in 2.2% of the donors. The sensitivity and specificity of pica in iron-deficient donors were 36% and 82%, respectively. Lower ferritin (p = .001), non-Asian race (p < .001), higher red cell distribution width (p < .001), younger age, and restless legs syndrome (p = .008) were independently associated with pica. Female sex is associated with iron deficiency but was not an independent predictor of pica suggesting that iron deficient males and females were equally susceptible to the development of pica behaviors. Donors with normal ferritin levels also reported pica, reinforcing the role of non-iron related factors in its presentation.

CONCLUSIONS

We have identified demographic, clinical, and biochemical predictors of pica that help identify those most at risk for developing pica behaviors, and thereby assist in its clinical diagnosis and treatment.

Management of Restless Legs Syndrome in Pregnancy and Lactation

Restless legs syndrome (RLS) affects about 20% of all pregnant women. RLS symptoms are usually moderate to severe in intensity during pregnancy and can result in insomnia, depression, and other adverse outcomes. Although iron deficiency has been implicated as a potential etiological factor, other mechanisms can also play a role. Nonpharmacologic methods are the primary recommended form of treatment for RLS in pregnancy and lactation. Iron supplementation may be considered when the serum ferritin is low; however, several patients are unable to tolerate iron or have severe symptoms despite oral iron replacement. Here, we describe a case of severe RLS in pregnancy and illustrate the dilemmas in diagnosis and management. We review the literature on the prevalence, diagnosis, course, possible underlying pathophysiologic mechanisms and complications of RLS in pregnancy. We describe current best evidence on the efficacy, and safety of nonpharmacologic therapies, oral and intravenous iron supplementation, as well as other medication treatments for RLS in pregnancy and lactation. We highlight gaps in the literature and provide a practical guide for the clinical management of RLS in pregnancy and during breastfeeding.

Validity and reliability of the suggested immobilization test for measurement of restless legs syndrome severity in adults with multiple sclerosis

OBJECTIVE/BACKGROUND

Adults with multiple sclerosis (MS) often present with conditions that mimic restless legs syndrome (RLS), thereby adding complexity into the assessment of RLS severity. The current gold-standard measures of RLS severity rely on a fixed seven-day time frame, which limits the ability of these measures for studying acute changes in RLS severity. The present study examined if subjective and objective scores from the suggested immobilization test (SIT) provide a valid and reliable acute measure of RLS severity in persons with MS.

PATIENTS/METHODS

Participants with MS and RLS (n = 20) and MS without RLS (n = 20) were matched by age, gender, and disability. All participants completed validated questionnaires for RLS severity followed by the SIT, conducted at 18:00 (±15 min) on the same day of the week for two consecutive weeks. Participants wore accelerometer devices for seven nights to capture periodic limb movements (PLMs) during the night.

RESULTS

Self-reported RLS severity during the SIT had excellent construct validity and convergent validity, but moderate test-retest reliability. Device-measured PLMs, while not themselves a direct measure of RLS severity, were significantly associated with PLMs during the night and had excellent test-retest reliability during the SIT in adults with MS.

CONCLUSIONS

Our results suggest that the SIT represents a valid acute measure for capturing self-reported sensory aspects of RLS severity and should be considered in future research and clinical practice as a standardized acute measure of subjective RLS severity in adults with MS who present with RLS.

Restless legs syndrome and perceived olfactory and taste dysfunction: A community-based study

BACKGROUND AND PURPOSE

Restless legs syndrome (RLS) has been suggested as a prodromal symptom of Parkinson disease (PD). Olfactory or taste dysfunction can also occur preceding PD diagnosis. However, whether RLS is associated with chemosensory dysfunction remains unknown. We thus aim to investigate the association between RLS and perceived olfactory and taste dysfunction.

METHODS

We performed a cross-sectional analysis including 90,337 Chinese adults free of neurodegenerative diseases in the Kailuan study in 2016. Presence of RLS was defined using revised RLS diagnostic criteria or the Cambridge-Hopkins questionnaire for RLS. Perceived olfactory and taste dysfunction was collected via a questionnaire. The association between RLS and perceived olfactory and taste dysfunction was assessed using logistic regression model, adjusting for potential cofounders such as age, sex, and medical history.

RESULTS

RLS was associated with high odds of having perceived olfactory and/or taste dysfunction (adjusted odds ratio = 5.92, 95% confidence interval = 3.11-11.3). The significant association persisted when using the Cambridge-Hopkins questionnaire (adjusted odds ratio = 5.55, 95% confidence interval = 2.37-13.0) or when excluding participants with major chronic diseases.

CONCLUSIONS

RLS was associated with increased odds of perceived olfactory and taste dysfunction.

Association of proton pump inhibitor and histamine H2-receptor antagonists with restless legs syndrome

Restless legs syndrome (RLS) is a common sensorimotor disorder, which can disrupt sleep and is thought to be caused in part by low cellular iron stores. Proton pump inhibitors (PPI) and histamine H₂-receptor antagonists (H₂A) are among the most commonly used drugs worldwide and show evidence of causing iron deficiency. We conducted a case/non-case observational study of blood donors in the United States (N = 13,403; REDS-III) and Denmark (N = 50,323; Danish Blood Donor Study, DBDS), both of which had complete blood count measures and a completed RLS assessment via the Cambridge–Hopkins RLS questionnaire. After adjusting for age, sex, race, BMI, blood donation frequency, smoking, hormone use, and iron supplement use, PPI/H₂A use was associated with RLS (odds ratio [OR] = 1.41; 95% confidence interval [CI], 1.13–1.76; p = 0.002) in REDS-III for both PPI (OR = 1.43; CI, 1.03–1.95; p = 0.03) and H₂A (OR = 1.56; CI, 1.10–2.16; p = 0.01). DBDS exhibited a similar association with PPIs/H₂As (OR = 1.29; CI, 1.20–1.40; p < 0.001), and for PPIs alone (OR = 1.27; CI, 1.17–1.38; p < 0.001), but not H₂As alone (OR = 1.18; CI, 0.92–1.53; p = 0.2). We found no evidence of blood iron stores mediating this association. The association of PPI, and possibly H₂A, consumption with RLS independent of blood iron status and other factors which contribute to RLS risk suggest the need to re-evaluate use of PPI/H₂A in populations at particular risk for RLS.

Effect of continuous positive airway pressure treatment of obstructive sleep apnea-hypopnea in multiple sclerosis: A randomized, double-blind, placebo-controlled trial (SAMS-PAP study)

OBJECTIVE

The aim of this study was to evaluate the effect of continuous positive airway pressure (CPAP) treatment on the Fatigue Severity Scale (FSS, preplanned primary outcome), another fatigue measure, sleep quality, somnolence, pain, disability, and quality of life in multiple sclerosis (MS) patients with obstructive sleep apnea-hypopnea (OSAH).

METHODS

In a randomized, double-blind trial (NCT01746342), MS patients with fatigue, poor subjective sleep quality, and OSAH (apnea-hypopnea index of ⩾ 15 events per hour/sleep), but without severe OSAH (apnea-hypopnea index > 30, and 4% oxygen desaturation index > 15 events/hour or severe somnolence), were randomized to fixed CPAP or sham CPAP for 6 months. Outcome assessments were performed at 3 and 6 months.

RESULTS

Of 49 randomized patients, 34 completed the protocol. Among completers, FSS did not improve with CPAP compared to sham at 6 months. FSS tended to improve (p = 0.09), and sleepiness (Epworth Sleepiness Scale) improved significantly (p = 0.03) at 3 months with CPAP compared to sham, but there were no other improvements with CPAP at either study evaluation.

CONCLUSION

In non-severe OSAH patients, CPAP did not significantly improve the primary outcome of FSS change at 6 months. In secondary analyses, we found a trend to improved FSS, and a significant reduction in somnolence with CPAP at 3 months.

Association between restless legs syndrome and peripheral neuropathy: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

The coexistence of peripheral neuropathy (PN) and restless legs syndrome (RLS) or Willis-Ekbom disease is relatively frequent, but its prevalence has shown a high variability across studies. In addition, several reports have shown data suggesting the presence of PN in patients with idiopathic RLS.

METHODS

A search was undertaken using the PubMed, Embase and Web of Science Databases, from 1966 to 6 December 2020, crossing the search term 'restless legs syndrome' with 'neuropathy', 'polyneuropathy' (PNP) and 'peripheral neuropathy', and the references of interest for this topic were identified; a meta-analysis was performed, according to PRISMA guidelines, and a calculation of pooled prevalences, where appropriate, was made using standard methods.

RESULTS

Restless legs syndrome has been reported in 5.2%-53.7% of patients with PN (average 21.5%; 95% confidence interval 18.6%-24.5%), and PN has been reported in 0%-87.5% of patients with RLS (average 41.8%; 95% confidence interval 39.9%-43.6%), both being significantly more frequent than in controls. The heterogeneity across studies could be due to differences in the diagnostic criteria used for both RLS and PN. RLS is a frequent clinical complaint in patients with PN of different aetiologies, mainly diabetic PN, uraemic PNP, familial amyloid PNP, Charcot-Marie-Tooth disease and chronic dysimmune inflammatory PNP. Recent neurophysiological findings suggest the presence of small sensory fibre loss in patients diagnosed with idiopathic RLS, but it remains to be determined whether RLS associated with small sensory fibre loss and idiopathic RLS are different clinical entities.

CONCLUSIONS

Future studies including clinical and neurophysiological assessment and skin biopsy involving a large series of patients with PN and RLS are needed for a better understanding of the association between these two entities.

Restless legs syndrome is increased in postural orthostatic tachycardia syndrome

STUDY OBJECTIVES

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).

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

We need to do better: A systematic review and meta-analysis of diagnostic test accuracy of restless legs syndrome screening instruments

This systematic review and meta-analysis evaluated the diagnostic accuracy of screening instruments for restless legs syndrome (RLS) and reports sensitivity, specificity, positive (PPV) and negative predictive values (NPV). Searches for primary studies were conducted in electronic databases. Of the 1541 citations identified, 52 were included in the meta-analysis. The methodological quality of each study was evaluated using QUADAS-2. Only 14 studies assessed the reference standard in all participants or in all screen-positives and a selection of screen-negatives. Bivariate meta-analysis of these 14 studies estimated median sensitivity to be 0.88 (0.72-0.96) and specificity 0.90 (0.84-0.93); based on a population prevalence of 5%, the calculated PPV was 0.31 (0.27-0.34). For all 52 studies, with either full or partial verification of RLS status, we constructed best-case scenario sensitivities and specificities at pre-defined levels of prevalence: across all samples, when prevalence is 5%, the median best-case scenario PPV is 0.48 with significant between-study heterogeneity. No RLS screening instruments can currently be recommended for use without an expert clinical interview in epidemiological studies. For conditions with statistically low prevalence such as RLS, the specificity, not the sensitivity, of a screening instrument determines true prevalence. Therefore, future instruments should maximize specificity. We provide guidelines on RLS ascertainment in epidemiological studies that requires a two-step process with clinical interview following a screening test, and given the poor reporting quality of many RLS epidemiological studies, we include an RLS reporting checklist.

Feasibility and efficacy of a physical activity intervention for managing restless legs syndrome in multiple sclerosis: Results of a pilot randomized controlled trial

BACKGROUND

This pilot randomized controlled trial examined the feasibility and efficacy of a physical activity behavior change intervention for improving restless legs syndrome (RLS) severity and secondary sleep outcomes among a sample of adults with multiple sclerosis (MS).

METHODS

Participants with MS(N=15) were randomly assigned into intervention(n=8) or waitlist control(n=7) conditions. The physical activity intervention was delivered over a 16-week period and outcomes were assessed at baseline and immediately following the 16-week period in both conditions.

RESULTS

There was a significant, positive effect of the intervention on overall RLS severity (p=.01;η_ρ²=.43), severity during the night(p=.03,η_ρ²=.35), severity during the day while resting(p=.01,η_ρ²=.44), and severity during the day while active(p<.01,η_ρ²=.61), and non-significant improvements in RLS severity while falling asleep (p=.33,η_ρ²=.09). There were significant positive effects on sleep satisfaction(p<.01,η_ρ²=.49) and non-significant improvements in self-reported global sleep quality(p=.35,η_ρ²=.08). There was a significant intervention effect on self-reported time in bed(p=.03,η_ρ²=.37) and total sleep time(p=.03,η_ρ²=.36), and non-significant improvements in self-reported sleep latency (p=.08,η_ρ²=.25), sleep efficiency(p=.27,η_ρ²=.11), and daytime sleepiness (p=.52,η_ρ²=.04;p=.35,η_ρ²=.08;p=.51,η_ρ²=.04). There was no significant effect of the intervention on device-measured sleep quality.

CONCLUSIONS

We provide preliminary evidence for the feasibility and efficacy of a physical activity intervention for reducing RLS severity and potentially improving self-reported sleep outcomes in adults with MS. CLINICALTRIALS.

GOV IDENTIFICATION NUMBER

NCT04061681.

Differential associations of age and Alzheimer's disease with sleep and rest-activity rhythms across the adult lifespan

This study aimed to identify differences between physiological age-related and Alzheimer's disease (AD)-related alterations in sleep and rest-activity rhythm. All participants (n = 280; 20-90 years) underwent clinical assessments, [¹¹C] Pittsburgh compound B-positron emission tomography, and actigraphic monitoring. In cognitively normal adults without cerebral amyloid-β, older age was associated with earlier timing of circadian phase and robust rest-activity rhythm, but sleep quantity and quality were mostly unaffected by age. While preclinical AD was associated with earlier circadian timing, clinical AD exhibited later timing of daily rhythm and increased sleep duration. In conclusion, our findings suggest that older age itself leads to a more regular daily activity rhythm, but does not affect sleep duration. While preclinical AD made the effects of age-related phase advance more prominent, clinical AD was related to later circadian timing and increased sleep duration.

Effects of menopause on sleep quality and sleep disorders: Canadian Longitudinal Study on Aging

OBJECTIVES

Sleep complaints are common during the menopause transition. However, it is difficult to disentangle changes in sleep related to aging from those directly due to menopause. We compared sleep disorders in 45 to 60-year-old women in a large population-based study, according to menopausal status.

METHODS

Women aged between 45 and 60 years who self-reported menopausal status were selected from the Canadian Longitudinal Study of Aging, excluding those with prior hysterectomy. Participants completed assessments for overall sleep satisfaction, hours of daily sleep, sleep-onset insomnia, sleep-maintenance insomnia, daytime somnolence, rapid eye movement sleep behavior disorder (RBD), restless leg syndrome (RLS), and obstructive sleep apnea (OSA). Each sleep variable was compared between postmenopausal and pre/perimenopausal women using multivariate regression, adjusting for potential confounders.

RESULTS

Among 6,179 women included, 3,713 (60.1%; age 55.7 ± 3.3 years) were postmenopausal and 2,466 (39.9%) were pre/perimenopausal (age 49.80 ± 3.1 years). Compared with pre/perimenopausal women, postmenopausal women were more often reported requiring ≥30 minutes to fall asleep (20.4% vs 15.5%; adjusted odds ratio [AOR] 1.24, 95% confidence interval [CI] 1.00-1.53) and were more likely to meet criteria for possible sleep-onset insomnia disorder (10.8% vs 7.3%; AOR 1.51, 95% CI 1.07-2.12). Postmenopausal women were also more likely to screen positive for OSA (14.6% vs 10.4%; AOR 1.48, 95% CI 1.14-1.92). The two groups did not differ on sleep dissatisfaction (32.4% vs 29%), daytime somnolence disorder (1.6% vs 1.3%), sleep-maintenance insomnia disorder (17% vs 14.5%), RLS (23.5% vs 20.9%), or RBD (3.9% vs 4.0%).

CONCLUSIONS

Menopause is associated with increased sleep-onset insomnia. Postmenopausal women also are more likely to screen positive for OSA. However, menopausal status is not associated with sleep maintenance, somnolence, or RLS, and RBD. : Video Summary:http://links.lww.com/MENO/A501.