Vitamin D and Restless Legs Syndrome: A Review of Current Literature

Rethinking pediatric "Periodic Limb Movement Disorder" (PLMD): A clinical review of pediatric PLMD and consensus criteria for an updated pediatric diagnostic category "Sleep Leg Movement Disorder of Childhood"

Pediatric Periodic Limb Movement Disorder (PLMD) is a sleep-related movement disorder characterized by repetitive limb movements, primarily in the legs, which disrupt sleep and potentially cause daytime functional impairments. This article reviews the clinical features, diagnostic challenges, and treatment approaches for pediatric PLMD, while emphasizing the importance of distinguishing it from simple periodic limb movements (PLMS). Although PLMD is associated with various conditions such as iron deficiency, attention-deficit/hyperactivity disorder (ADHD), and neurodevelopmental disorders, the exact prevalence and underlying mechanisms remain unclear. Diagnosis requires polysomnography, and adherence to standardized criteria, complicates the process. Treatment primarily involves iron supplementation, with behavioral interventions and off-label pharmacological options considered in more severe cases. Due to recent appreciation of non-periodic movements in many cases, this review proposes the introduction of a new diagnostic category, Sleep Leg Movement Disorder of Childhood (SLMDC), which would encompass a broader spectrum of pediatric limb movement disorders. This new category aims to improve clinical care by allowing for more tailored interventions and better communication between healthcare providers and families. SLMDC would facilitate long-term follow-up and offer a framework for understanding the continuum of these disorders from childhood to adulthood. The paper concludes by advocating for the retention of PLMD as a subset of SLMDC, emphasizing the need for updated diagnostic criteria and treatment strategies that reflect the unique characteristics of pediatric patients.

Role of vitamins in the pathogenesis and treatment of restless leg syndrome: A systematic review and meta-analysis

We performed a meta-analysis to assess the role of vitamins in the possible pathogenesis and treatment of RLS (Restless Leg Syndrome). A systematic search of the PubMed, Cochrane, Embase, and Web of Science databases was conducted. Fifty-nine studies on the relationship between vitamins and RLS were included, as well as four randomized controlled trials (RCTs) on vitamin treatment of RLS. Compared with non-RLS patients, serum vitamin D levels were significantly lower both in primary (P =  0.009) and secondary (P =  0.003) RLS patients, and appeared to be positively correlated with disease severity. Serum folate levels were lower in pregnant RLS patients than in pregnant non-RLS patients (P =  0.007), but this phenomenon was not seen in non-pregnant RLS patients (P =  0.65). Vitamin B12 (P =  0.59) and B1 (P =  0.362) deficiencies were not found in RLS patients. Oral vitamin B6 significantly improved primary RLS (P < 0.0001), while vitamin D did not (P =  0.05). Oral vitamin C (P < 0.00001), E (P < 0.0001), and vitamin C +  E (P < 0.00001) all significantly improved hemodialysis-associated RLS with equal efficacy. Vitamin C is equivalent to 0.18 mg of pramipexole for the treatment of RLS (P =  0.81). In this meta-analysis, low vitamin D levels were found in patients with RLS, low folate levels were associated with RLS only in pregnant women, and vitamin C/E/B6 may improved symptoms in patients with RLS. These results suggest that vitamin deficiency or insufficiency may be related to the pathogenesis of RLS.

Prerequisites for self-care actions in individuals with restless legs syndrome-A deductive qualitative analysis based on the COM-B model

Restless Legs Syndrome (RLS) affects 3% of the world's population, causing tingling sensations primarily in the legs. Incorporating self-care activities could improve the management of RLS symptoms, yet knowledge about effective self-care actions is limited. This study employs the Capability, Opportunity, and Motivation-Behaviour (COM-B) model to explore self-care behaviours in individuals with RLS, as research in this area is sparse. Qualitative content analysis of interviews with 28 participants with RLS, 26 subcategories emerged, aligning with the COM-B model's components. The first part, Capability, highlighted the importance of being able to be in motion, while the second, Opportunity referred to situations where there was a lack of trust and guidance for self-care. The third part, Motivation, emphasised the importance of fixed routines of sleep, rest, and activity. These identified prerequisites can inform the development of screening instruments and patient-reported outcome measures to evaluate self-care needs and interventions for individuals with RLS.

Current and emerging pharmaceutical strategies for the treatment and management of restless legs syndrome

INTRODUCTION

Restless legs syndrome (RLS) is a sensory-motor sleep disorder that affects up to 13% of adults in the Western world and 2-4% of children. It impairs night sleep with an impact on daily performances and life quality. Thus, moderate-to-severe RLS requires pharmacological treatment.

AREAS COVERED

In the present review, which is based on PubMed searches with no time limits, the authors discuss the recommended pharmacotherapy for RLS in addition to other emerging treatment options. The authors provide coverage to the current recommendations for both adults and pediatric patients with RLS.

EXPERT OPINION

Current evidence suggests removing all causes of secondary RLS, including iron deficiency, chronic renal failure, drugs, and treating other sleep disorders that may worsen symptoms. Also, intermittent RLS should be addressed with behavioral measures and on-demand therapy. For chronic persistent RLS, α2δ calcium channel ligands are a first-line pharmacological approach, whereas dopamine agonists are associated with increased risk and should be spared. When RLS is refractory to first-line treatment, polytherapy, or opioid monotherapy should be considered. Nonetheless, some patients may not reach sustained symptom relief. Further research is needed to better understand the pathophysiology of RLS and to develop newer more effective drugs.

Effects of Dietary Supplementation in Patients with Restless Legs Syndrome: A Systematic Review

Restless legs syndrome (RLS) is a common neurological disorder. It disrupts sleep and well-being and is often associated with other conditions. This review examines the potential of dietary supplements to manage RLS symptoms and reduce reliance on medications. A total of 10 randomized clinical trials involving 482 participants were analyzed, focusing on the impact of various supplements on symptom severity, sleep quality, and daytime sleepiness. Findings suggest some supplements may have positive results. Magnesium oxide and vitamin B6 significantly improved sleep quality and RLS symptoms, with magnesium showing greater effectiveness. Vitamin D supplementation did not show significant benefits. Oral iron has promising results, indicating potential efficacy but issues related to compliance and absorption. Both vitamins C and E positively affect RLS symptoms, likely due to their antioxidant properties. Valerian improved RLS and sleep but did not show a statistically significant improvement. Despite these encouraging results, a high risk of bias was noted in half of the studies, emphasizing the need for more rigorous research. Overall, this review suggests that dietary supplements may be a promising approach to managing RLS. However, further investigation is required to confirm the efficacy and safety.

Gender medicine and sleep disorders: from basic science to clinical research

Several pivotal differences in sleep and sleep disorders are recognized between women and men. This is not only due to changes in hormonal balance during women's reproductive life, such as in pregnancy and menopause. Women are more likely to report insomnia and non-specific symptoms of apneas, such as fatigue or mood disturbance, compared to men. Thus, it is important for clinicians and researchers to take sex and gender differences into account when addressing sleep disorders in order to acknowledge the biology unique to women. We present a narrative review that delves into the primary sleep disorders, starting from basic science, to explore the impact of gender differences on sleep and the current status of research on women's sleep health.

Restless leg syndrome as a complication of primary hyperparathyroidism: insights from a retrospective study

INTRODUCTION

Restless leg syndrome (RLS) is an invalidating neurological disorder with a complex, largely unknown pathophysiology. While RLS is observed in Parkinson's disease and in renal failure, idiopathic cases are common. Limited reports associate RLS with parathyroid hormone (PTH). This study analyzes a cohort of patients with primary hyperparathyroidism (PHPT) and chronic post-surgical hypoparathyroidism (hypo PTH), to investigate RLS prevalence, and associated risk factors.

METHODS

Ninety-five patients (54 PHPT, 41 hypo PTH) were consecutively enrolled at the bone metabolism outpatient clinic. The revised IRLSSG diagnostic criteria were used to diagnose RLS, with assessments conducted through face-to-face interviews and neurological examination. When RLS was confirmed, the RLS severity scale was applied. Retrospective records included calcium-phosphate metabolism-related parameters, surgery details, renal lithiasis, fragility fractures, and densitometric features (T-score).

RESULTS

RLS was diagnosed in 22.2% PHPT patients, compared to 4.9% of patients with hypo PTH (p = 0.02). Of RLS diagnosed patients, 91.7% had a history of parathyroidectomy, compared to 47.6% of patients without RLS (p = 0.01). Most of the operated patients reported that surgery determined an improvement of symptoms; however, mean score severity of RLS at our evaluation was 15/40, defined as moderate. PTH and calcium levels were not statistically associated to the presence of RLS.

CONCLUSION

Our study suggests that PHPT may be one of the etiologies of RLS. Parathyroidectomy alleviates symptoms in the vast majority of the cases but does not remove them.

Current updates in Restless Legs Syndrome: A pragmatic review

Restless legs syndrome (RLS), also called Willis–Ekbom disease (WED), affects approximately 3% of the global population, with higher incidence in Caucasians and women. This review explores the latest advancements in the diagnosis, pathophysiology, and management of RLS, and it highlights the recent changes in diagnostic criteria that improve specificity. The diagnostic spectrum now includes atypical presentations involving the upper limbs and other body parts. The new diagnostic specifiers categorize RLS more effectively into chronic-persistent or intermittent types, and a clinical significance specifier has been introduced to better address the disorder’s effects on daily life. RLS management has shifted toward a balanced approach with non-pharmacological strategies and lifestyle changes, supported by updated pharmacological treatment protocols including iron therapy designed to mitigate risks such as augmentation. Notably, gabapentinoids have emerged as a superior treatment option over dopamine agonists owing to their lower risk of augmentation and superior safety profile. Innovative treatments, such as the FDA-approved tonic motor activation device and new pharmacological agents, serve as alternatives for treating medication-refractory RLS, thereby expanding the therapeutic landscape. Additionally, this review addresses the specific considerations for managing RLS in special groups, including pregnant women, individuals with chronic kidney disease, and patients with comorbid conditions such as Parkinson’s disease and multiple sclerosis. We emphasizes the dynamic nature of RLS research and highlight the critical need for ongoing studies to further elucidate the complex mechanisms underlying RLS, as well as to refine the treatment modalities to enhance patient outcomes.

Unveiling the pathophysiology of restless legs syndrome through transcriptome analysis

The aim of this study was to analyze signaling pathways associated with differentially expressed messenger RNAs in people with restless legs syndrome (RLS). Seventeen RLS patients and 18 controls were enrolled. Coding RNA expression profiling of 12,857 gene transcripts by next-generation sequencing was performed. Enrichment analysis by pathfindR tool was carried-out, with p-adjusted ≤0.001 and fold-change ≥2.5. Nine main different network groups were significantly dysregulated in RLS: infections, inflammation, immunology, neurodegeneration, cancer, neurotransmission and biological, blood and metabolic mechanisms. Genetic predisposition plays a key role in RLS and evidence indicates its inflammatory nature; the high involvement of mainly neurotropic viruses and the TORCH complex might trigger inflammatory/immune reactions in genetically predisposed subjects and activate a series of biological pathways-especially IL-17, receptor potential channels, nuclear factor kappa-light-chain-enhancer of activated B cells, NOD-like receptor, mitogen-activated protein kinase, p53, mitophagy, and ferroptosis-involved in neurotransmitter mechanisms, synaptic plasticity, axon guidance, neurodegeneration, carcinogenesis, and metabolism.

Risk factors affecting the sleep quality of patients on dialysis: A single-center cross-sectional study

Sleep quality is among the common complication in patients on dialysis and serious affect their health and quality of life; however, other associated risk factors are unclear. This study aimed to investigate the risk factors affecting sleep quality in patients on dialysis. Data were collected from 260 patients who met the inclusion criteria at out hospital from May 2023 to October 2023. Questionnaires were completed by patients, and biochemical indicators were obtained from past medical records. Univariate and multifactor analyses were used to find factors influencing sleep quality in patients on dialysis. Simple linear regression results showed that female, type of kidney primary disease, high systolic blood pressure (SBP), pruritus, pruritus frequency, restless legs syndrome (RLS), anxiety, and depression were associated with poor sleep quality. Blood biochemical parameters showed that low sodium and calcium levels and high ferritin levels were associated with poor sleep quality. Multiple linear regression statistics showed that female, pruritus, RLS, high SBP, depression, and high ferritin levels were associated with poor sleep quality. This study showed that female, chronic nephritis syndrome, high SBP, pruritus, RLS, low mood. and high ferritin levels were associated with poor sleep quality. Future development of individual nursing and targeted therapies is key to improving sleep quality in patients on dialysis.

Correlates of Restless Legs Syndrome in Older People

Background: We examined the association between restless legs syndrome (RLS) and comprehensive geriatric assessment (CGA) data in two older European populations. The second goal was to evaluate correlates of their quality of life (QoL). Methods: Diagnostic criteria of the International RLS Study Group (IRLSSG) and elements of CGA were used in this study. Results: Among the examined 246 participants, 77 (31.3%) suffered from RLS, more often in the UK (39.4%) than in Poland (25.4%) (p = 0.019). In the multivariate logistic regression model, female sex [OR (CI) = 3.29 (1.51-7.21); p = 0.0014], the number of medications per day [OR (CI) = 1.11 (1.02-1.20); p = 0.011] and alcohol consumption [OR (CI) = 5.41 (2.67-10.95); p < 0.001] increased the probability of RLS. Residing in Poland [OR (CI) = 3.06 (1.36-6.88); p = 0.005], the presence of RLS [OR (CI) = 2.90 (1.36-6.17); p = 0.004], chronic heart failure, [OR (CI) = 3.60 (1.75-7.41); p < 0.001], osteoarthritis [OR (CI) = 2.85 (1.47-5.49); p = 0.0016], and urinary incontinence [OR (CI) = 4.74 (1.87-11.9); p < 0.001] were associated with a higher probability of mobility dimension problems in the QoL. Higher physical activity was related to a lower probability of mobility problems [OR (CI) = 0.85 (0.78-0.92); p < 0.001]. Conclusions: female sex, the number of medications and alcohol consumption are independent correlates of RLS in older adults. RLS together with several chronic medical conditions and a low physical activity level were independent correlates of the mobility dimension of the QoL.

Vitamin D Status Modestly Regulates NOD-Like Receptor Family with a Pyrin Domain 3 Inflammasome and Interleukin Profiles among Arab Adults

Vitamin D (VD) deficiency has been associated with inflammation and dysregulation of the immune system. The NLRP3 inflammasome, a critical immune response component, plays a pivotal role in developing inflammatory diseases. VD hinders NLRP3 inflammasome activation and thus exerts anti-inflammatory effects. This study aimed to analyze the effect of VD deficiency on circulating levels of NLRP3 inflammasomes (NLRP3 and caspase-1) and associated interleukins (IL-1α, IL-1β, IL-18, IL-33 and IL-37) in Saudi adults. Methods: A total of 338 Saudi adults (128 males and 210 females) (mean age = 41.2 ± 9.1 years and mean BMI 31.2 ± 6.5 kg/m2) were included. Overnight-fasting serum samples were collected. Participants were stratified according to their VD status. Serum levels of NLRP3 inflammasomes and interleukins of interest were assessed using commercially available immuno-assays. Individuals with VD deficiency had significantly lower mean 25(OH)D levels than those with a normal VD status (29.3 nmol/L vs. 74.2 nmol/L, p < 0.001). The NLRP3 levels were higher in the VD-deficient group than their VD-sufficient counterparts (0.18 vs. 0.16, p = 0.01). Significant inverse associations were observed between NLRP3 levels with age (r = -0.20, p = 0.003) and BMI (r = -0.17, p = 0.01). Stepwise regression analysis identified insulin (β = 0.38, p = 0.005) and NLRP3 (β = -1.33, p = 0.03) as significant predictors of VD status, explaining 18.3% of the variance. The findings suggest that the VD status modestly regulates NLRP3 inflammasome and interleukin activities. This may provide novel insights into the pathogenesis and management of inflammatory disorders.

Exploring the causes of augmentation in restless legs syndrome

Long-term drug treatment for Restless Legs Syndrome (RLS) patients can frequently result in augmentation, which is the deterioration of symptoms with an increased drug dose. The cause of augmentation, especially derived from dopamine therapy, remains elusive. Here, we review recent research and clinical progress on the possible mechanism underlying RLS augmentation. Dysfunction of the dopamine system highly possibly plays a role in the development of RLS augmentation, as dopamine agonists improve desensitization of dopamine receptors, disturb receptor interactions within or outside the dopamine receptor family, and interfere with the natural regulation of dopamine synthesis and release in the neural system. Iron deficiency is also indicated to contribute to RLS augmentation, as low iron levels can affect the function of the dopamine system. Furthermore, genetic risk factors, such as variations in the BTBD9 and MEIS1 genes, have been linked to an increased risk of RLS initiation and augmentation. Additionally, circadian rhythm, which controls the sleep-wake cycle, may also contribute to the worsening of RLS symptoms and the development of augmentation. Recently, Vitamin D deficiency has been suggested to be involved in RLS augmentation. Based on these findings, we propose that the progressive reduction of selective receptors, influenced by various pathological factors, reverses the overcompensation of the dopamine intensity promoted by short-term, low-dose dopaminergic therapy in the development of augmentation. More research is needed to uncover a deeper understanding of the mechanisms underlying the RLS symptom and to develop effective RLS augmentation treatments.