Oxidative stress and autonomic nervous system functions in restless legs syndrome

Efficacy and Safety of Acupuncture for Restless Legs Syndrome in Patients with End-Stage Renal Disease: A Randomized-Controlled Trial at Hospital-Based Hemodialysis Center

Background: Restless legs syndrome (RLS) is frequent in patients with hemodialysis (HD) and occurs predominantly in its most severe forms. The study was conducted to evaluate the efficacy and safety of acupuncture for RLS in patients with end-stage renal disease (ESRD) at hospital-based HD center. Methods: This single-blind, randomized controlled trial was performed on patients with HD and RLS who were randomly assigned to the experimental group and control group. Data were collected using the International Restless Legs Syndrome Rating Scale (IRLSRS), Insomnia Severity Index (ISI), and heart rate variability (HRV) records at baseline, after the therapeutic course (12 times/4 weeks), and 1-week follow-up. Result: A total of 47 patients were evaluated with IRLSRS score from 11 to 30 in this study. There were 41 patients enrolled in the study based on inclusion/exclusion criteria and allocated randomly into two groups. A total of 35 participants completed the trial, including 18 subjects in the experimental group and 17 subjects in the control group. The comparison of IRLSRS and ISI showed a significant reduction between two groups after acupuncture treatment (p = 0.002, p = 0.003). The ISI after 1-week follow-up also revealed significant decrease (p = 0.003). This HRV results showed that high frequency (HF%) increased significantly (p = 0.021) and low frequency (LF%) decreased significantly in the acupuncture group (p = 0.021). The generalized estimating equation showed that the IRLSRS improved by 2.902 points (p < 0.001) in the acupuncture group compared with the control group and by 1.340 points (p = 0.003) after 1-week follow-up. There were no adverse effects observed during HD in this study. Discussion: The authors conclude that acupuncture could effectively improve the symptoms of RLS significantly. The results from this study provide clinical evidence on the efficacy and safety of acupuncture to treat the patients with RLS at the HD center.

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.

Sleep disorders as both risk factors for, and a consequence of, stroke: A narrative review

BACKGROUND AND PURPOSE

Sleep disorders are increasingly implicated as risk factors for stroke, as well as a determinant of stroke outcome. They can also occur secondary to the stroke itself. In this review, we describe the variety of different sleep disorders associated with stroke and analyze their effect on stroke risk and outcome.

METHODS

A search term-based literature review ("sleep," "insomnia," "narcolepsy," "restless legs syndrome," "periodic limb movements during sleep," "excessive daytime sleepiness" AND "stroke" OR "cerebrovascular" in PubMed; "stroke" and "sleep" in ClinicalTrials.gov) was performed. English articles from 1990 to March 2023 were considered.

RESULTS

Increasing evidence suggests that sleep disorders are risk factors for stroke. In addition, sleep disturbance has been reported in half of all stroke sufferers; specifically, an increase is not only sleep-related breathing disorders but also periodic limb movements during sleep, narcolepsy, rapid eye movement (REM) sleep behavior disorder, insomnia, sleep duration, and circadian rhythm sleep-wake disorders. Poststroke sleep disturbance has been associated with worse outcome.

CONCLUSION

Sleep disorders are risk factors for stroke and associated with worse stroke outcome. They are also a common consequence of stroke. Recent guidelines suggest screening for sleep disorders after stroke. It is possible that treatment of sleep disorders could both reduce stroke risk and improve stroke outcome, although further data from clinical trials are required.

Coenzyme Q10 and Autoimmune Disorders: An Overview

Some 90 autoimmune disorders have been described in medical literature, affecting most of the tissues within the body. Autoimmune disorders may be difficult to treat, and there is a need to develop novel therapeutic strategies for these disorders. Autoimmune disorders are characterised by mitochondrial dysfunction, oxidative stress, and inflammation; there is therefore a rationale for a role for coenzyme Q10 in the management of these disorders, on the basis of its key role in normal mitochondrial function, as an antioxidant, and as an anti-inflammatory agent. In this article, we have therefore reviewed the potential role of CoQ10, in terms of both deficiency and/or supplementation, in a range of autoimmune disorders.

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

This review presents a detailed summary of the current literature regarding RLS and vitamin D deficiency. To our knowledge it is the first review of its kind. We review the prevalence of vitamin D deficiency in RLS as well as the evidence for the use of vitamin D supplementation in RLS management. We further examine the literature for proteomic and genetic evidence of a role for vitamin D in the pathogenesis of RLS. An alteration in vitamin D binding protein in RLS is one of the most consistent findings in the proteomic studies. Furthermore, we examine the interaction of vitamin D with calcium, phosphorus, and parathyroid hormone and the possible role of these connections in RLS. We also explore the possible nexus between RLS and vitamin D in renal disease, cardiovascular and cerebrovascular disease as well as inflammation. In addition, we review the potential interaction between vitamin D and RLS with iron, dopamine and other neurotransmitter systems including the endogenous opiate, serotoninergic, glutamatergic and adenosinergic systems. We also explore the role of vitamin D in RLS Augmentation (i.e., the paradoxical worsening of RLS symptoms when dopaminergic agents are used as a therapy for RLS). Although the literature is not entirely consistent in affirming vitamin D deficiency in RLS or the amelioration of RLS symptoms with vitamin D therapy, the collective studies overall indicate that vitamin D deficiency is common enough in RLS patients to suggest that RLS patients should have their vitamin D levels checked and any deficiency corrected as a standard of care. Highlights  Patients with Restless Legs Syndrome (RLS) may be deficient in vitamin D and therapy with vitamin D may ameliorate RLS. We present the first review dedicated solely to evaluating the relationship between RLS and vitamin D and present a case for the role of vitamin D in RLS pathogenesis.

Is Restless Legs Syndrome De Facto Thyroid Disease?

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

Effects of Exercise Training on the Autonomic Nervous System with a Focus on Anti-Inflammatory and Antioxidants Effects

Studies show that the autonomic nervous system (ANS) has an important impact on health in general. In response to environmental demands, homeostatic processes are often compromised, therefore determining an increase in the sympathetic nervous system (SNS)’s functions and a decrease in the parasympathetic nervous system (PNS)’s functions. In modern societies, chronic stress associated with an unhealthy lifestyle contributes to ANS dysfunction. In this review, we provide a brief introduction to the ANS network, its connections to the HPA axis and its stress responses and give an overview of the critical implications of ANS in health and disease—focused specifically on the immune system, cardiovascular, oxidative stress and metabolic dysregulation. The hypothalamic–pituitary–adrenal axis (HPA), the SNS and more recently the PNS have been identified as regulating the immune system. The HPA axis and PNS have anti-inflammatory effects and the SNS has been shown to have both pro- and anti-inflammatory effects. The positive impact of physical exercise (PE) is well known and has been studied by many researchers, but its negative impact has been less studied. Depending on the type, duration and individual characteristics of the person doing the exercise (age, gender, disease status, etc.), PE can be considered a physiological stressor. The negative impact of PE seems to be connected with the oxidative stress induced by effort.

Association of Oxidative Stress with Neurological Disorders

BACKGORUND

Oxidative stress is one of the main contributing factors involved in cerebral biochemical impairment. The higher susceptibility of the central nervous system to reactive oxygen species mediated damage could be attributed to several factors. For example, neurons use a greater quantity of oxygen, many parts of the brain have higher concentraton of iron, and neuronal mitochondria produce huge content of hydrogen peroxide. In addition, neuronal membranes have polyunsaturated fatty acids, which are predominantly vulnerable to oxidative stress (OS). OS is the imbalance between reactive oxygen species generation and cellular antioxidant potential. This may lead to various pathological conditions and diseases, especially neurodegenerative diseases such as, Parkinson's, Alzheimer's, and Huntington's diseases.

OBJECTIVES

In this study, we explored the involvement of OS in neurodegenerative diseases.

METHODS

We used different search terms like "oxidative stress and neurological disorders" "free radicals and neurodegenerative disorders" "oxidative stress, free radicals, and neurological disorders" and "association of oxidative stress with the name of disorders taken from the list of neurological disorders. We tried to summarize the source, biological effects, and physiologic functions of ROS.

RESULTS

Finally, it was noted that more than 190 neurological disorders are associated with oxidative stress.

CONCLUSION

More elaborated studies in the future will certainly help in understanding the exact mechanism involved in neurological diseases and provide insight into revelation of therapeutic targets.

Plasma thiol/disulphide homeostasis changes in patients with restless legs syndrome

OBJECTIVES

Restless legs syndrome (RLS) is a common neurological condition. Oxidative stress plays an important role in its pathogenesis. Thiol-disulphide homeostasis (TDH) is a new biomarker of oxidative stress. We studied plasma TDH to determine whether TDH could be used as a new biomarker for RLS and evaluated correlations between TDH and various disease severity rating scales.

METHODS

A total of 25 RLS patients and 25 healthy controls were included into the study. TDH status was determined using an automated spectrophotometric analysis method and correlations were analyzed between the TDH status and various disease rating scales in the RLS patients.

RESULTS

Plasma total (401±27 μmol/L) and native thiol (354±30 μmol/L) levels were significantly lower, but disulphide level (24±6 μmol/L) was significantly (<0.0001) higher in the RLS patients compared to the controls (455±36, 424±37, 15±5 μmol/L, respectively). The disulphide/native thiol and disulphide/total thiol ratios increased, in contrast, native thiol/total thiol ratio decreased significantly in the RLS patients compared to the healthy controls (<0.0001). The disulphide levels correlated positively with age and various rating scores of the RLS patients. International Restless Legs Syndrome Study Group (IRLSSG) rating score and age correlated negatively with the total and native thiol levels.

CONCLUSIONS

Our findings indicate increased oxidative stress in the RLS patients reflected by decreased native and total thiol, and increased disulphide levels and positive correlations between the disulphide levels and various rating scores. We suggest dynamic TDH status to be used as a novel biomarker for the diagnosis and follow-up of the RLS patients.

Effect of electroacupuncture on restless legs syndrome (RLS) in hemodialysis patients: A protocol for systematic review and meta-analysis

BACKGROUND

Restless legs syndrome (RLS) is frequent in dialysis patients and occurs predominantly in its most severe forms. The aim of the present study was to evaluate the effects of electroacupuncture (EA) in hemodialysis patients with RLS by heart rate variability (HRV) monitor.

METHODS

One hundred twelve subjects who were hemodialysis patients with RLS will be divided into 2 groups: experimental and control. Each subject will receive the treatment relevant to their group 2 times a week for 4 weeks. After 4 weeks of treatment the subject will enter a 2-week washout period, after which the subjects will switch groups. Measurements will include HRV recordings, International Restless Legs Syndrome Rating Scale (IRLSRS) and Insomnia Severity Index (ISI).

RESULT

The results of this study will systematically evaluate the effectiveness and safety of electoracupuncture intervention for hemodialysis patients with RLS.

DISCUSSION

This study is the first investigation to analyze the relationship between EA and the change of HRV by an objective monitor. If the findings of the current trial are positive, this study will also help support an effective, safe and cheap approach to clinical treatment of this challenging disorder, help foster improved understanding the relationship between autonomic nervous system and RLS, and ultimately contribute to elucidate the mechanisms of EA.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04356794; registration date: April 22, 2020.

Restless legs syndrome is associated with mast cell activation syndrome

STUDY OBJECTIVES

Mast cell activation syndrome (MCAS) is an inflammatory and allergic disorder. We determined the prevalence of restless legs syndrome (RLS) in MCAS because each common syndrome may be inflammatory in nature and associated with dysautonomia.

METHODS

Individuals with MCAS were evaluated for RLS by two standard questionnaires. Prevalence comparisons included spouse control patients and two prevalence publications. MCAS diagnosis required mast cell (MC) symptoms in ≥ 2 organs plus ≥ 1 elevated MC mediators, improvement with MC therapy, and/or increased intestinal MC density. Clinical variables were studied.

RESULTS

There were 174 patients with MCAS (146 female, 28 male, mean age 44.8 years) and 85 spouse control patients (12 female, 73 male, mean age 50.9 years). Patients with MCAS as a whole had a higher prevalence of RLS (40.8%) than spouse control (12.9%) (P < .0001) Male patients with MCAS had a higher prevalence of RLS (32.1%) than male controls (12.3%, odds ratio [OR] 3.4, confidence interval [CI] 1.2-9.7, P = .025), American men (8.4%, OR 5.2, CI 2.2-12.0, P < .001), and French men (5.8%, OR 7.7, CI 3.4-17.1, P < .001). Female patients with MCAS also had a higher prevalence of RLS (42.5%) than female controls (16.7%) but this did not reach statistical significance perhaps because of the sample size of the female controls. However, female patients with MCAS had a statistically higher prevalence of RLS than American women (10.0%, OR 6.7, CI 4.5-9.7, P < .0001) and French women (10.8%, OR 6.1, CI 4.4-8.6, P < .0001).

CONCLUSIONS

RLS appears to be associated with MCAS. Effects of mast cell mediators, inflammation, immune mechanisms, dysautonomia, or hypoxia may theoretically activate RLS in MCAS.

Restless legs syndrome, periodic limb movements during sleep and cardiovascular risk

Multiple mechanisms may modulate an association between restless legs syndrome/Willis-Ekbom disease (RLS/WED) and cardiovascular disease (CVD), including chronic sleep deprivation, intermittent, periodic limb movements in sleep (PLMS)-related autonomic fluctuations and possible autonomic dysfunction intrinsically associated with RLS per se. The purpose of this paper is to review the existing RLS/WED literature focusing on the pathophysiologic evidence for possible associations between RLS/WED and PLMS with CVD and events (CVE). Specific intrinsic dysautonomic aspects of the disease, which may contribute to generating CVD, are separately discussed. The association between RLS/WED and both CV risk factors and CVD still remains elusive. Although several shared pathophysiological causes could explain these possible relationships, the emerging body of literature focusing on these disorders remains controversial. Not only longitudinal population-based studies and meta-analyses, but also more animal models and therapeutic interventions are needed in order to build a sufficiently robust body of evidence on this topic.

Lower cardiovagal tone and baroreflex sensitivity associated with hepatic insulin resistance and promote cardiovascular disorders in Tibetan minipigs induced by a high fat and high cholesterol diet

AIMS

A long-term high-fat/cholesterol (HFC) diet leads to hepatic insulin resistance (IR), which is associated with autonomic dysfunction and cardiovascular diseases risk increasing. However, whether this occurs in Tibetan minipigs remains unknown. We tested that a long-term HFC diet caused hepatic IR and promote cardiovascular disorders in Tibetan minipigs, and are associated with the reduction of cardiovagal tone and baroreflex sensitivity (BRS).

METHODS

Male Tibetan minipigs were fed either a standard diet or a HFC diet, and were euthanized at 12 weeks. Thereafter, the minipigs were tested for biochemical blood indices, glucose tolerance, blood pressure, heart rate variability (HRV), BRS, and insulin receptor substrate (IRS)-associated gene and protein expression levels, as well as cardiac function.

RESULTS

HFC-fed minipigs developed IR by increasing body weight, total cholesterol, fasting blood glucose and insulin levels, and nonesterified fatty acid (NEFA) and high sensitive C-reactive protein (hs-CRP) levels, glucose intolerance. Increased adipose cell size, hepatic fat deposition, malondialdehyde (MDA) content and NEFA level, down-regulation of IRS1, IRS2, PI3K, Akt, p-Akt, Glut2 and PGC1ɑ expression concomitant with up-regulation of mTOR, GSK3β, TNF-ɑ, FOXO1, p-mTOR and p-p70S6K expression in the liver tissue, as well as hypertension and left ventricular diastolic dysfunction were observed in HFC-fed minipigs. HRV parameters and BRS values were further significantly reduced. Furthermore, multiple linear regression analysis showed that the development of hepatic IR toward cardiovascular disease was associated with low HFnu, RMSSD, BRS and LV -dp/dtmax, high NEFA, high hepatic TG content.

CONCLUSION

These data suggest that HFC-fed Tibetan minipigs develop hepatic IR and promote cardiovascular disorders, and are associated with lower cardiovagal tone and BRS.

Physiological and pathological covariates of persistent concussion-related fatigue: results from two regression methodologies

BACKGROUND

Fatigue severity in persons with mild traumatic brain injury (mTBI) has received little research attention, despite its typically positively skewed nature. Investigation of covariates across a range of fatigue severity may provide insight into important contributors.

OBJECTIVE

To assess the relative significance of a priori-hypothesized covariates of physiological and pathological (mental and physical) fatigue in persons with mTBI/concussion, applying ordinary least squares (OLS) and quantile regression (QR) approaches.

METHODS

We conducted a cross-sectional investigation in 80 participants with mTBI/concussion (mean age 45.4 ± 10.1 years, 59% male). The fatigue severity scale (FSS) was used as an outcome measure. Predictors of this outcome, grouped into physiological and pathological models of fatigue were assessed using OLS and QR.

RESULTS

The mean total FSS score was 46.13 ± 14.59, and the median was 49 (interquartile range 37-57), demonstrating positive skewness. Fatigue severity was associated with variables within the mental, psychological and psychiatric domains at different levels of the fatigue score distribution.

CONCLUSION

Results highlighted that some covariates had a significant impact on the FSS total score at non-central parts of its distribution, while others exhibited significant impact across the entire distribution. Addressing covariates of fatigue across the severity continuum can enhance research and clinical management.

Restless legs syndrome in Parkinson's disease and increased cardiovascular risk

ABSTRACT Restless legs syndrome (RLS) is a disorder commonly found in patients with Parkinson's disease, with descriptions for both conditions impairing dopaminergic transmission in central nervous system. Previous studies in varied populations indicate an association between the presence of RLS and increased cardiovascular risk and, so far, there are no consistent studies of this association in Parkinson's disease. Objective: To analyze the influence of RLS on cardiovascular risk in patients with Parkinson's disease. Methods: We reviewed the medical records of 202 patients diagnosed with Parkinson's disease and verified the presence of RLS, cardiovascular comorbidities, blood pressure measurements, lipid profiles and Framingham Risk Scores. Results: Statistically significant higher values of total cholesterol were found for the RLS group (mean 216.6 mg/dL), as well as for LDL cholesterol (mean 145 mg/dL). No statistical difference was found among the other factors. Conclusion: Patients with Parkinson's disease and RLS have a higher prevalence of dyslipidemia than patients without RLS, suggesting a correlation between restless legs and hyperlipidemia. It is questioned whether the dopaminergic substrate is the main factor in the genesis of the syndrome, as even with the use of dopaminergic agonists by both groups, it was possible to observe differences between groups. The hypothesis of the real interference of the syndrome treatment as a protective factor for cardiovascular risk was generated.

Heart rate variability in restless legs syndrome and periodic limb movements of Sleep

INTRODUCTION

The relationship between the autonomic nervous system and restless legs syndrome (RLS) and periodic limb movements of sleep (PLMS) consists of varied and somewhat conflicting reports. In order to further elucidate these complexities, a retrospective analysis of polysomnography (PSG) records and clinical data was performed.

METHODS

Records from 233 adult subjects were randomly selected and organized into one of four groups ("non-RLS/PLMS" [n=61], "RLS" [n=60], "PLMS" [n=58], and "RLS/PLMS" [n=54]). Heart rate variability (HRV) analysis was based on 5-minute samples of 2-lead electrocardiogram data isolated from PSG recordings during wakefulness and NREM sleep, and included mean RR interval (labeled "NN") and standard deviation of the RR intervals (labeled "SDNN"), and HRV power, very low frequency (VLF), low frequency (LF), and high frequency (HF) spectral bands.

RESULTS

A significant reduction in the VLF band in the PLMS group as compared to the non-RLS/PLMS group (542±674 vs. 969±1025 ms², p=0.038) was found in wakefulness. Statistically significant differences were seen in the PLMS group as compared to the non-RLS/PLMS group with a reduction in SDNN (p=0.001) and the HF (p=0.001) band, and an increase in HRV power (p=0.001), and the VLF (p=0.005) and LF (p=0.001) bands in NREM sleep.

CONCLUSIONS

The PLMS group exhibited reduced basal sympathetic activity in wakefulness, but basal sympathetic predominance during NREM sleep, distinguishing this group from the RLS and RLS/PLMS groups.

Nocturnal periodic limb movements decrease antioxidant capacity in post-stroke women

OBJECTIVES

Considerable evidence suggests that periodic limb movements during sleep (PLMS) are associated with cardiovascular risk and poor stroke outcome. However, the pathogenesis for this association in stroke patients remains largely unknown.

MATERIALS AND METHODS

This cross-sectional study enrolled 112 consecutive patients who were admitted to rehabilitation ward due to ischemic stroke. Polysomnography and laboratory tests for oxidative stress and inflammatory biomarkers including C-reactive protein, interleukin 6, total antioxidant capacity (TAC), and urinary 8-hydroxy-2-deoxyguanosine were conducted.

RESULTS

Patients were stratified into three categories according to their PLMS index. Patients in the PLMS index ≥15 group were significantly older (P = 0.011), presented a significantly higher National Institute of Health Stroke Scale at stroke onset (P = 0.032), and lower Barthel index (P = 0.035) than patients in the PLMS index <5 group. The level of TAC differed significantly (P = 0.018) among the three groups. Multivariate linear regression analyses show that the PLMS index was negatively and independently correlated with TAC (P = 0.024) in women. Besides, multivariate logistic regression analyses also reveal that patients with a PLMS index ≥15 compared with the referent PLMS index <5 had a 7.58-fold increased relative hazard for stroke recurrence (odds ratio 7.58, [1.31-43.88], P = 0.024).

CONCLUSIONS

This study suggests that PLMS was independently associated with decreased antioxidant capacity in women with ischemic stroke.

Impact of Restless Legs Syndrome on Cardiovascular Autonomic Control

STUDY OBJECTIVES

To examine whether patients with restless legs syndrome demonstrate specific alterations in cardiovascular autonomic control.

METHODS

Patients with moderate-severe restless legs syndrome (n = 20, 80% female) and controls (n = 20) matched for age, sex, body mass index, and free of hypertension and cardiovascular disease were enrolled. We assessed cardiovagal baroreflex gain via the modified Oxford technique, sympathetically mediated vascular responses to isometric exercise to fatigue, bradycardiac response to Valsalva maneuver, and respiratory sinus arrhythmia during paced breathing. Standard electrocardiography, beat-by-beat arterial pressure, respiration, and popliteal blood flow velocity were recorded continuously.

RESULTS

Resting blood pressure and heart rate were similar between groups. However, baroreflex gain averaged 14.3 ± 1.4 msec/mm Hg in restless legs syndrome and was lower than in controls (22.6 ± 3.5 msec/mm Hg, P = 0.04). Hemodynamic responses to isometric exercise were similar between groups, though participants with restless legs syndrome had lower leg blood flow (P < 0.001), with greater leg vascular resistance (P < 0.0001), before and during isometric exercise. Respiratory sinus arrhythmia and Valsalva ratios were similar between groups. Neither baroreflex gain nor vascular resistance was correlated with sleep duration, sleep quality, or symptom duration.

CONCLUSION

Patients with restless legs syndrome demonstrate compromised cardiovagal control, specific to the arterial baroreflex, with greater peripheral vascular resistance, potentially due to heightened sympathetic outflow. These autonomic alterations may directly relate to the higher prevalence of cardiovascular disease in restless legs syndrome.

Reduced bone resorption and increased bone mineral density in women with restless legs syndrome

OBJECTIVE

To investigate bone resorption and formation markers as well as bone mineral density in women with restless legs syndrome (RLS).

METHODS

This was a prospective cross-sectional case-control study involving drug-naive women with RLS and age- and body mass index (BMI)-matched female controls. Routine blood analyses, markers of bone formation, procollagen 1 n-terminal peptide, bone resorption, c-telopeptide of type 1 collagen (CTX), sclerostin, and bone mineral density (BMD) were compared between the 2 groups. Pregnant or breastfeeding women and individuals with comorbidities other than iron deficiency, type 2 diabetes mellitus, or hypertension were excluded.

RESULTS

A significant increase in lumbar BMD was found among 78 women with RLS as compared to 78 age- and BMI-matched controls (p = 0.001). The proportion of patients with osteopenia as defined by a lumbar T score was significantly lower among patients with RLS (p = 0.040). CTX and sclerostin were significantly lower in patients with RLS (p = 0.006 and p = 0.011, respectively), as were the levels of 25-hydroxy vitamin D3, calcemia, and free T3 (p = 0.017, p = 0.017, and p = 0.002, respectively).

CONCLUSIONS

Despite lower 25-hydroxy vitamin D3, patients with RLS had lower bone resorption markers, higher lumbar BMD, and lower frequency of lumbar osteopenia. As patients with RLS make movements night and day to decrease the severity of their symptoms, they unconsciously perform exercise, which may potentially explain the better bone profile among patients with RLS than in controls.

The Relationship of Restless Legs Syndrome to History of Pregnancy-Induced Hypertension

BACKGROUND

Restless legs syndrome (RLS), a burdensome sleep disorder, has been associated with cardiovascular disease (CVD), hypertension, diabetes, and related disorders. However, the relationship of RLS to history of pregnancy-induced hypertension (PIH), a predictor of subsequent CVD, diabetes, and associated conditions, remains little explored. In this study, we investigated the relationship of RLS to history of PIH in a sample of primary care patients.

METHODS

Participants were women aged ≥40 years drawn from an anonymous survey study of West Virginia primary care patients. Data collected included detailed information on demographics, lifestyle factors, sleep patterns, and reproductive/medical history; the survey also included an RLS diagnostic questionnaire. Women who were pregnant or unsure about their pregnancy status were excluded from the analyses.

RESULTS

Of the 498 participants in the final analytic sample, 24.5% met diagnostic criteria for RLS (17.9% with symptoms ≥once/week, 11.9% with symptoms ≥3 times/week); 73 (16.5% of parous women) reported a history of PIH, defined as physician-diagnosed preeclampsia or gestational hypertension. After adjustment for demographics, lifestyle characteristics, obesity, reproductive history, health conditions, and other factors, those reporting a history of PIH were approximately twice as likely to meet criteria for RLS (odds ratio [OR] = 1.9; 95% confidence interval [CI] = 1.1, 3.6). These associations increased in magnitude with increasing symptom frequency (adjusted OR for RLS with symptoms ≥3 times/week = 3.8; CI 1.9, 7.6; p for trend = 0.003).

CONCLUSIONS

History of PIH was strongly and positively related to current RLS in this study of primary care patients; these findings further support a possible role for metabolic dysregulation in RLS etiology.

Decreased baroreflex sensitivity is linked to sympathovagal imbalance, body fat mass and altered cardiometabolic profile in pre-obesity and obesity

OBJECTIVE

Though decreased baroreflex sensitivity (BRS), the predictor of cardiac morbidities and mortality has been reported in obesity, the mechanisms and metabolic biomarkers influencing BRS have not been studied. We aimed to assess the difference in cardiovascular (CV) risk profile in pre-obesity and obesity, and the contribution of body composition and cardiometabolic factors to CV risks in these two conditions.

METHODS

Obesity indices, body composition, blood pressure variability and autonomic function test parameters were recorded in 223 subjects divided into controls (n=72), pre-obese (n=77) and obese (n=74) groups. Insulin resistance (HOMA-IR), atherogenic index (AI), leptin, adiponectin, inflammatory and oxidative stress parameters were measured. Association and independent contribution of altered cardiometabolic parameters with BRS were performed by Pearson's correlation and multiple regression analysis, respectively.

RESULTS

BRS was significantly decreased in pre-obese and obese group compared to controls. Sympathovagal imbalance (SVI) in the form of increased sympathetic and decreased parasympathetic cardiac drives was observed in pre-obesity and obesity. There was significant difference in general markers of obesity (body mass index, and waist-to-hip ratio), between pre-obese and obese group, however no such difference was observed in body composition and cardiometabolic parameters between the two groups. AI, high sensitive C-reactive protein (hs-CRP) and ratio of basal metabolism to body fat (BM/BF) in pre-obese group, and AI, HOMA-IR, leptin, adiponectin, ratio of basal metabolism to body weight (BM/BW), BM/BF, inflammatory and oxidative stress markers in obese group had independent contribution to BRS. Among these metabolic biomarkers, BRS had maximum association with leptin (β=0.532, p=0.000) in the obese group and hs-CRP (β=0.445, p=0.022) in the pre-obese group.

CONCLUSIONS

The present study demonstrates decreased BRS, an important marker of increased CV risk in pre-obesity and obesity. The intensity of cardiometabolic derangements and CV risk was comparable between pre-obese and obese subjects. BM/BF ratio appears to be a better marker of metabolic activity in pre-obesity and obesity. SVI and increased basal metabolism appear to be the physiological link between metabolic derangements and CV risks in both pre-obesity and obesity.

Serum endocan levels in women with restless legs syndrome

BACKGROUND

Endocan is a recently introduced marker of endothelial dysfunction. The objective of this study was to compare serum endocan levels in patients with restless legs syndrome (RLS) and control subjects in order to elucidate whether RLS is associated with endothelial dysfunction.

METHODS

A total of 31 drug naïve female patients with RLS and 31 age- and BMI-matched women were included in the study. Patients with pathological or physiological conditions or with a history of medication use that could potentially influence endothelial functions were excluded, as well as those with alcohol or drug abuse history. The two groups were compared with routine blood tests and serum endocan levels.

RESULTS

Patients with RLS had lower serum endocan levels than the controls (P=0.037). There was a negative bivariate correlation between RLS severity score and serum endocan levels (r=-0.406, P=0.023). While white blood cell count was significantly higher in RLS group, 25-hydroxy vitamin D3, vitamin B12, transferrin saturation rate, and HDL-cholesterol were significantly lower. Creatininemia and diastolic blood pressure were also marginally insignificantly lower in RLS group. Due to the presence of differences between two groups in these variables, a linear regression analysis was performed that showed a positive association between endocan and creatininemia (β=0.310, P=0.022), and a negative association between endocan and RLS (β=-0.502, P<0.001).

CONCLUSION

The results of this study seem to suggest that patients with RLS may have better endothelial functions when compared with the general population and that these patients may be better protected against atherosclerosis.

Protective effects of ethyl pyruvate in cisplatin-induced nephrotoxicity

This study was performed to investigate the effect of ethyl pyruvate on changes in renal functions and oxidative stress related renal injury caused by cisplatin (cis-dichlorodiammine platinum-II; CDDP). Male Wistar albino rats were divided into four groups (n = 8): (1) control group (1 ml Ringer's lactate solution i.p.); (2) ethyl pyruvate (EP) group (50 mg/kg Ringer's EP solution (REPS) i.p.); (3) cisplatin group (a single dose of cisplatin (5 mg/kg, i.p.); and (4) cisplatin + EP group (a single dose of cisplatin (5 mg/kg, i.p.) + REPS 50 mg/kg/day, i.p.) for five days. At the sixth day, kidneys of rats were mounted to a Langendorff apparatus. Renal perfusion pressures were recorded. Blood samples were taken for serum urea, creatinine, total oxidant status (TOS), total antioxidant status (TAS) and oxidative stres index (OSI) evaluations. Kidney tissues were obtained for malondialdehyde (MDA) analyses and histopathological examination. Perfusion pressures, serum urea, creatinine, TOS, OSI and tissue MDA levels were found significantly higher, whereas TAS was notably lower in cisplatin group. Histopathological examination showed apparent renal paranchymal injury in cisplatin group. In cisplatin + REPS group, perfusion pressures, serum urea, creatinine and tissue MDA levels were decreased. Moreover, EP co-administration provided less inflammatory cell infiltration, tubular dilatation, whereas TOS, TAS and OSI improved significantly versus cisplatin group. These findings show that EP has protective effects against cisplatin nephrotoxicity.

Current trends in the management of uremic restless legs syndrome: a systematic review on aspects related to quality of life, cardiovascular mortality and survival

Restless legs syndrome (RLS) affects almost one out of three end-stage renal disease patients. This review assesses the current treatment options for uremic RLS and the potential benefits of those treatments on quality of life parameters, cardiovascular mortality and survival. A systematic review was conducted searching PubMed and Scopus by using the Cochrane and PRISMA guidelines. Fourteen studies met the inclusion criteria in which the international RLS study group criteria were used as the primary diagnostic tool. Both pharmacological and non-pharmacological approaches were found to reduce the severity of uremic RLS symptoms. Only four studies reported changes on aspects related to quality of life while those changes were also associated with health benefits that resulted in reduced cardiovascular risk. The severity of uremic RLS symptoms can be ameliorated by using dopamine agonists and gabapentin, intravenous iron, exercise or supplementation with vitamins C and E, although some of those treatment benefits may be transient. There is a lack of strong evidence regarding the effects of the pharmacological approaches on quality of life and cardiovascular survival and mortality. In contrast exercise has been proven beneficial in both reducing the RLS symptoms' severity score and improving the quality of life.

Restless legs syndrome status as a predictor for lower physical function

OBJECTIVE

To examine the potential long-term impact of restless legs syndrome (RLS) and other common sleep complaints on subsequent physical function (PF), we conducted a longitudinal analysis of 12,556 men in the Health Professionals Follow-up Study.

METHODS

We used a set of questions recommended by the International RLS Study Group to assess RLS in 2002. We asked questions regarding other sleep complaints--insomnia, sleep fragmentation, and excessive daytime sleepiness--in 2004. We used the Physical Function (PF-10) survey of the Short Form-36 Health Survey to characterize PF in 1996 and 2008. We examined the 2008 PF-10 scores across categories of baseline RLS (2002), adjusted for age, 1996 PF-10 score, and other potential confounders.

RESULTS

The participants with RLS at baseline had significantly lower PF-10 score 6 years later than those without RLS (mean difference = -2.32, p = 0.01), after adjusting for potential confounders. The magnitude of difference in PF-10 score for RLS symptoms ≥ 15 times/month vs no RLS was more than that of a 5-year increase of age or moderate amount of smoking. Having daily daytime sleepiness and sleep duration ≥ 9 hours/day were associated with lower mean PF value than not having these symptoms (p < 0.05 for both).

CONCLUSIONS

RLS and other sleep complaints are associated with lower PF. Our findings need to be replicated by more longitudinal studies including women and populations of other social and cultural backgrounds. It is important to understand whether RLS is an independent risk factor or a marker for other unknown risk factors for disability.

A study examining depression in restless legs syndrome

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSION

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

Prospective study of restless legs syndrome and risk of erectile dysfunction

In our previous cross-sectional study, we found that restless legs syndrome (RLS) was associated with erectile dysfunction (ED). Thus, we conducted a prospective study to examine whether RLS was associated with a higher risk of developing ED based on 6 years of follow-up among 10,394 men (mean age = 63.4 years) in the Health Professionals Follow-up Study. RLS was assessed in 2002 using a set of standardized questions recommended by the International RLS Study Group. Erectile function was assessed by means of questionnaires in 2000, 2004, and 2008. We identified 1,633 incident ED cases. Men with RLS were more likely to develop ED (relative risk = 1.38, 95% confidence interval: 1.14, 1.68; P = 0.001) than were those without the syndrome, after adjustment for potential confounders, such as age, body mass index, smoking, physical activity, other sleep disorders, and snoring status. A higher frequency of RLS symptoms was also associated with an increased risk of ED (P(trend) = 0.001). In conclusion, men with RLS had a higher risk of ED, and the magnitude of the risk increased with a higher frequency of RLS symptoms. Combinations of other sleep disorders with RLS further increased the risk of ED.

Oxytocin ameliorates remote liver injury induced by renal ischemia-reperfusion in rats

Renal ischemia-reperfusion (IR) causes remote liver damage. Oxytocin has anti-inflammatory and antioxidant effects. The main purpose of this study was to evaluate the protective function of oxytocin (OT) in remote liver damage triggered by renal IR in rats. Twenty four rats were randomly divided into four different groups, each containing 8 rats. The groups were as follows: (1) Sham operated group; (2) Sham operated+OT group (3) Renal IR group; (4) Renal IR+OT group. OT (500µg/kg) was administered subcutaneously 12 and 24 hours before and immediately after ischemia. At the end of experimental procedure, the rats were sacrificed, and liver specimens were taken for histological assessment or determination of malondialdehyde (MDA), total oxidant status (TOS), total antioxidant status (TAS), paraoxonase (PON-1) activity and nitric oxide (NO). The results showed that renal IR injury constituted a notable elevation in MDA, TOS, Oxidative stress index (OSI) and significantly decreased TAS, PON-1 actvity and NO in liver tissue (p<0.05). Additionally renal IR provoked significant augmentation in hepatic microscopic damage scores. However, alterations in these biochemical and histopathological indices due to IR injury were attenuated by OT treatment (p<0.05). These findings show that OT ameliorates remote liver damage triggered by renal ischemia-reperfusion and this preservation involves suppression of inflammation and regulation of oxidant-antioxidant status.

Prospective study of restless legs syndrome and coronary heart disease among women

BACKGROUND

Previous cross-sectional studies suggested a positive association between restless legs syndrome (RLS) and coronary heart disease (CHD). This observation was not confirmed by subsequent prospective studies. However, these prospective studies did not take into account the duration of RLS symptoms. Therefore, we prospectively examined whether RLS was associated with an increased risk of CHD in women who participated in the Nurses' Health Study, taking into account the duration of RLS symptoms.

METHODS AND RESULTS

A total of 70 977 women (mean age, 67 years) who were free of CHD and stroke at baseline (2002) were followed up until 2008. Physician-diagnosed RLS was collected via questionnaire. CHD was defined as nonfatal myocardial infarction or fatal CHD. Women with RLS at baseline had a marginally higher risk of developing CHD (multivariable-adjusted hazard ratio, 1.46; 95% confidence interval, 0.97-2.18) compared with women without RLS. The risk was dependent on duration of symptoms: 0.98 (95% confidence interval, 0.44-2.19) for women with RLS for <3 years and 1.72 (95% confidence interval, 1.09-2.73) for women with RLS for ≥3 years (P trend=0.03). The multivariable-adjusted hazard ratios of women with RLS for ≥3 years were 1.80 (95% confidence interval, 1.07-3.01) for nonfatal myocardial infarction and 1.49 (95% confidence interval, 0.55-4.04) for fatal CHD relative to women without RLS.

CONCLUSIONS

We observed that women with RLS for at least 3 years had an elevated risk of CHD. These results suggest that RLS or RLS-associated conditions may contribute to the origin of cardiovascular disease.

The Effects of a Gentle Yoga Program on Sleep, Mood, and Blood Pressure in Older Women with Restless Legs Syndrome (RLS): A Preliminary Randomized Controlled Trial

Objective. To examine the effects of yoga versus an educational film program on sleep, mood, perceived stress, and sympathetic activation in older women with RLS. Methods. Participants were drawn from a larger trial regarding the effects of yoga on cardiovascular disease risk profiles in overweight, sedentary postmenopausal women. Seventy-five women were randomized to receive either an 8-week yoga (n = 38) or educational film (n = 37) program. All 75 participants completed an RLS screening questionnaire. The 20 women who met all four diagnostic criteria for RLS (n = 10 yoga, 10 film group) comprised the population for this nested study. Main outcomes assessed pre- and post-treatment included: sleep (Pittsburgh Sleep Quality Index), stress (Perceived Stress Scale), mood (Profile of Mood States, State-Trait Anxiety Inventory), blood pressure, and heart rate. Results. The yoga group demonstrated significantly greater improvements than controls in multiple domains of sleep quality and mood, and significantly greater reductions in insomnia prevalence, anxiety, perceived stress, and blood pressure (all P's≤0.05). Adjusted intergroup effect sizes for psychosocial variables were large, ranging from 1.9 for state anxiety to 2.6 for sleep quality. Conclusions. These preliminary findings suggest yoga may offer an effective intervention for improving sleep, mood, perceived stress, and blood pressure in older women with RLS.

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

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