Restless legs syndrome in lung transplant recipients

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

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

Restless legs syndrome in systemic lupus erythematosus: A case-control study

Sleep disturbances in systemic lupus erythematosus (SLE) are not well understood. The restless legs syndrome (RLS) is one of the frequent occurring sleep disturbances in SLE. The aim of this study was to evaluate the prevalence of RLS and its characteristics in SLE. We evaluated, in a prospective case-control study, 26 patients with SLE and 26 patients without SLE in an age- and sex-matched control group. An RLS-positive diagnosis met International RLS Study Group (IRLSSG) criteria. We used standardized questionnaires, which included demographic data, medical history and sleep assessment. We used validated questionnaires and scales to assess sleep. There were 23/26 females (88.46%) in each group; the mean patient age in the SLE subgroup was 51.65 years, while in the control subgroup, 52.07 years (range 30-74). Nine (34.2%) patients had RLS-positive criteria in the SLE group and 2 (7.69%) of 26 in the control group. Eight out of 9 patients described RLS onset after SLE was diagnosed. In the SLE group, 8 cases were of moderate severity and 1 was considered mild. The control group had one mild and one moderate case of RLS. RLS prevalence in SLE is higher and the quality of sleep is poorer compared with the control group.

Are serum vitamin D, calcium and phosphorous associated with restless leg syndrome? A systematic review and meta-analysis

BACKGROUND

It is hypothesized that vitamin D deficiency, and calcium/phosphate imbalance could be involved in the pathophysiology of restless leg syndrome (RLS). This systematic review and meta-analysis of observational studies were carried out to reach a firm conclusion regarding the possible association between vitamin D, calcium and phosphorous levels with RLS in end-stage renal disease (ESRD) patients, other comorbidities and healthy population.

METHODS

PubMed, Scopus, ISI Web of Science, and Cochrane's library were systematically searched up to June 2020. Quality assessment of the included observational studies was performed using Newcastle-Ottawa Quality Assessment Scale. Statistical analyses were done using STATA 11.2. A P-value <0.05 were considered statistically significant.

RESULTS

A total of 36 studies involving 9590 participants were included in this systematic review and meta-analysis. We found that serum vitamin D level is significantly lower (WMD -3.39 ng/mL; 95% CI, -5.96 to -0.81; P = 0.010; I² = 86.2%) and phosphorous (SMD 0.19; 95% CI, 0.04-0.34; P = 0.011; I² = 83.6%) is significantly higher in RLS individuals compared to the non-RLS individuals. However, the mean difference of serum calcium was not significant in comparison between RLS and control groups (SMD -0.01; 95% CI, -0.19 to 0.18; P = 0.957; I² = 89.2%).

CONCLUSION

Results revealed a significant association between serum vitamin D and phosphorous with RLS. However, further prospective cohort studies and clinical trials are needed for better understanding of the relationship between these variables.

Insomnia and Relationship With Immunosuppressant Therapy After Lung Transplantation

BACKGROUND

Lung transplant recipients are at high risk of developing sleep disorders such as insomnia, but the prevalence and features are currently poorly characterized within this population. Since these disorders are associated with increased morbidity and mortality, it is important to identify them to optimize the care of lung transplant recipients. We sought to evaluate the prevalence of insomnia within our university-based lung transplant clinic and determine whether a relationship exists between insomnia and exposure to immunosuppressant medications following transplantation.

METHODS

Participants were recruited through the University of Wisconsin Hospital and Clinics Lung Transplant Clinic (N = 125). Participants (n = 92) completed the adult sleep history questionnaire, which included the Insomnia Severity Index (ISI) to assess for insomnia (defined as ISI score >10). Cumulative tacrolimus exposure was determined in 73 patients by performing an area under the curve calculation to assess for a potential relationship between tacrolimus exposure and insomnia.

RESULTS

The prevalence of insomnia was 40% within this population. Although no difference in time since transplant was found, cumulative mean ± standard error of the mean tacrolimus exposure was significantly higher in patients with insomnia versus those without insomnia (17 190 ± 1673 ng·d/mL vs 12 130 ± 1630 ng·d/mL, respectively; P = .04). Estimated tacrolimus exposure was not greater with increasing frequency of insomnia complaints (analysis of variance P = .54).

CONCLUSION

In our population, insomnia is common after lung transplantation, with prevalence greater than the general population. Higher cumulative exposure to tacrolimus may contribute to insomnia in this group. Future research should investigate the relationship between immunosuppressant therapy and development of sleep disorders.

Restless Legs Syndrome Following Lung Transplantation: Prevalence and Relationship With Tacrolimus Exposure

CONTEXT

Complications following lung transplantation are common and significantly reduce quality of life, and increase morbidity and mortality. Increasing evidence suggests sleep disorders are prevalent following lung transplantation, but factors associated with their development are not known.

OBJECTIVES

We sought to evaluate the prevalence of restless legs syndrome (RLS) in a lung transplant population and determine if a relationship exists between RLS and exposure to immunosuppressant medications.

DESIGN, SETTING, AND PARTICIPANTS

Subjects were recruited through the University of Wisconsin Hospital and Clinics Lung Transplant Clinic (N = 125). Participants (N = 81) completed sleep questionnaires, including the four RLS diagnostic criteria, insomnia severity index, and Sheehan disability scale. Cumulative tacrolimus exposure was determined in 62 subjects by calculating an area under the curve (AUC) to assess for a relationship with restless legs syndrome.

RESULTS

Prevalence of RLS was 35 percent. Cumulative mean ± SEM tacrolimus exposure was similar in patients with RLS versus those without RLS (17446 ± 1855 ng days/mL vs. 15303 ± 1643 ng days/mL, respectively; p = 0.42). Insomnia severity index scores (12.5 ± 1.0 vs 6.8 ± 0.7, p < 0.0001) and Sheehan disability scores (7.8 ± 1.3 vs 3.6 ± 0.6, p = 0.003) were significantly higher in those with vs those without RLS symptoms, respectively.

CONCLUSIONS

Our data confirms increased prevalence of RLS following lung transplantation reported by previous studies. RLS symptoms were not related to estimated tacrolimus exposure. Predictors of RLS following lung transplantation need to be further investigated to better identify and control RLS symptoms and reduce associated insomnia and disability.

Poor sleep in organ transplant recipients: self-reports and actigraphy

Solid organ transplant recipients are at increased risk of poor sleep due to pharmacotherapy and co-morbidities, but sleep problems are often unrecognized and untreated. Study aims were to measure rates of occurrence, characteristics, and correlates of poor sleep in recipients. The Pittsburgh Sleep Quality Index (PSQI) and sleep parameters measured by wrist actigraphy were obtained at baseline from 143 kidney, liver, heart, lung, or pancreas transplant recipients enrolled in a psychosocial intervention trial to improve symptoms and quality of life. Rates of poor sleep were determined using accepted clinical cutoffs; 41% (58 of 143) were poor sleepers (PSQI > 8) and 36% used sleep medications in the past month. Fifteen percent reported having obstructive sleep apnea (OSA) and 4% reported restless legs syndrome (RLS). Based on actigraphy (n = 73), 69% lacked sleep efficiency (SE), 32% took >30 min to fall asleep, 88% awakened during the night for more than 30 min, and 25% slept less than six h per night. Obesity and use of psychotropics or sleep medications, and pain were independent risk factors for poor objectively measured sleep. Poor sleep is an undertreated problem in transplantation. Screening for sleep problems and behavioral therapies with sleep hygiene instruction may benefit recipients.

Incidence of restless legs syndrome and its correlates

BACKGROUND

Restless legs syndrome (RLS) is a common sensorimotor disorder whose incidence is not known. The aim of the study was to determine the incidence and correlates of RLS in a population-based sample.

METHODS

We obtained data from the Tucson Cohort of the Sleep Heart Health Study, a prospective multicenter study. This cohort included 535 participants aged ≥ 40 years, who answered questions regarding RLS on the 2002 and 2006 sleep surveys. For this study, RLS was defined as the presence of all 4 International RLS Study Group criteria, with symptoms occurring ≥ 5 days/month and associated with at least moderate distress.

RESULTS

Mean age of the predominantly Caucasian (90.8%) participants on the 2002 survey was 59.8 ± 9.7 years; 52.2% were women. RLS prevalence was 4.1% in 2002 and 7.7% in 2006. The yearly incidence of RLS was 1.7% (6.6% over 4 years). Multivariate analyses demonstrated that estrogen use (OR = 2.5, 95% CI: 1.17-5.10) and self-reported obstructive lung disease (OR = 2.8, 95% CI: 1.37-5.83) were independent risk factors predicting incident RLS. Incident RLS was associated with higher prevalence of insomnia (26.5% vs. 7.6%, p = 0.001), increased sleepiness (38.2% vs. 22%, p = 0.036); and higher sleeping pill use in 2006 (23.5% vs. 9.7%, p = 0.019).

CONCLUSION

The incidence of RLS in this population sample was 1.7% per year. Use of estrogen and history of obstructive lung disease were associated with a significantly higher incidence of RLS. RLS, in turn, was associated with insomnia and increased sleepiness.

Restless legs syndrome--theoretical roles of inflammatory and immune mechanisms

Theories for restless legs syndrome (RLS) pathogenesis include iron deficiency, dopamine dysregulation and peripheral neuropathy. Increased prevalence of small intestinal bacterial overgrowth (SIBO) in controlled studies in RLS and case reports of post-infectious RLS suggest potential roles for inflammation and immunological alterations. A literature search for all conditions associated with RLS was performed. These included secondary RLS disorders and factors that may exacerbate RLS. All of these conditions were reviewed with respect to potential pathogenesis including reports of iron deficiency, neuropathy, SIBO, inflammation and immune changes. A condition was defined as highly-associated if there was a prevalence study that utilized an appropriate control group. Small case reports were recorded but not included as definite RLS-associated conditions. Fifty four diseases, syndromes and conditions have been reported to cause and/or exacerbate RLS. Of these, 38 have been reported to have a higher prevalence than age-matched controls, 9 have adequate sized reports and have general acceptance as RLS-associated conditions and 7 have been reported in case report form. Overall, 42 of the 47 RLS-associated conditions (89%) have also been associated with inflammatory and/or immune changes. In addition, 43% have been associated with peripheral iron deficiency, 40% with peripheral neuropathy and 32% with SIBO. Most of the remaining conditions have yet to be studied for these factors. The fact that 95% of the 38 highly-associated RLS conditions are also associated with inflammatory/immune changes suggests the possibility that RLS may be mediated or affected through these mechanisms. Inflammation can be responsible for iron deficiency and hypothetically could cause central nervous system iron deficiency-induced RLS. Alternatively, an immune reaction to gastrointestinal bacteria or other antigens may hypothetically cause RLS by a direct immunological attack on the central or peripheral nervous system.

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

PURPOSES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Comparison of two infrared devices in their effectiveness in reducing symptoms associated with RLS

This study was conducted to assess whether two kinds of near-infrared light devices, using different wavelengths and frequencies, impact symptoms associated with restless legs syndrome (RLS) differently. A recent randomized controlled study showed that symptoms associated with RLS can be diminished with near-infrared light treatment for a limited time. We wanted to assess whether different wavelengths and frequencies had an impact on its effectiveness. Twenty-five volunteers with symptoms of RLS were randomly assigned to either Anodyne® or HealthLight™ treatment. Both groups underwent 12 treatments with near-infrared light, three times a week for 4 weeks. A validated RLS rating scale was used to track changes. The two groups were not different in reported symptoms at baseline (p=0.37) and after 4 weeks of treatment (p=0.88). There was a significant improvement of symptoms between week 0 and week 4 (p<0.001); the difference in change indicated virtually the same improvement between the two groups. Although the two near-infrared light devices used different wavelengths and frequencies and one device used additional red light, they both produced significant improvement in the symptoms associated with RLS after 4 weeks of treatment.

Obstructive sleep apnea and immunity: relationship of lymphocyte count and apnea hypopnea index

OBJECTIVES

The impact of chronic poor quality sleep on immunity as seen in obstructive sleep apnea (OSA) has not been evaluated. We aim to explore the relationship between lymphocytes, neutrophil, and total leukocyte counts with severity stratified apnea hypopnea index (AHI) in patients with OSA.

METHODS

A retrospective review of 119 patients' medical records diagnosed with OSA from October 2005 to July 2006 was performed. Data collected included demographics, comorbidities, total leukocyte, neutrophil, and lymphocyte count, body mass index (BMI), AHI, and Epworth sleepiness scores (ESS). Three AHI strata were constructed: mild (5-14), moderate (15-29), and severe (>30). Data were fitted in a linear regression model on which lymphocyte counts were the dependent variable against age, BMI, and AHI. An interaction product was also explored (age*BMI). All tests were two-sided; a P < 0.05 was considered statistically significant. We used Statview Version 5.01 (SAS Institute, Inc., Cary, NC) for the analysis.

RESULTS

Our study showed a linear association among AHI and BMI (P = 0.0017), but did not show association between lymphocyte count with either BMI (P = 0.33) or AHI (P = 0.90). A negative association between lymphocytes and age (P = 0.02) that persisted after adjustments for BMI and AHI was found. An interaction product (age*AHI) was not associated with lymphocyte count (P = 0.87). No correlation was found between peripheral blood count (P = 0.29) or neutrophil counts (P = 0.38) and AHI.

CONCLUSION

We found OSA-induced sleep interruption not associated with lymphocyte, neutrophil, or peripheral blood cell count alterations. This information is useful for researchers evaluating the influence of sleep disruption on immunity.

Central neuraxial anaesthesia presenting with spinal myoclonus in the perioperative period: a case series

Introduction

Perioperative spinal myoclonus is extremely rare. Many anaesthetists and perioperative practitioners may not diagnose or manage this complication appropriately when it occurs. This case report of unusual acute spinal myoclonus following regional anaesthesia highlights certain aspects of this rare complication that have not previously been published.

Case presentations

A series of four consecutive patients who developed acute lower-limb myoclonus following spinal or epidural anaesthesia are described. The case series occurred at three different hospitals and involved four anaesthetists over a 3-year period. Two Caucasian men, aged 90-years-old and 67-years-old, manifested unilateral myoclonus. Two Caucasian women, aged 64-years-old and 53-years-old, developed bilateral myoclonus. Myoclonus was self-limiting in one patient, treated with further regional anaesthesia in one patient and treated with intravenous midazolam in two patients. The overall outcome was good in all patients, with no recurrence or sequelae in any of the patients.

Conclusion

This case series emphasizes that spinal myoclonus following regional anaesthesia is rare, has diverse pathophysiology and can have diverse presentations. The treatment of perioperative spinal myoclonus should be directed at the aetiology. Anaesthetists and perioperative practitioners who are unfamiliar with this rare complication should be reassured that it may be treated successfully with midazolam.

Increased frequency of restless legs syndrome in chronic obstructive pulmonary disease patients

BACKGROUND

Despite complaints of poor sleep being very common in people with chronic obstructive pulmonary disease (COPD), restless legs syndrome (RLS) symptoms have not been extensively investigated in these patients.

OBJECTIVE

To assess the prevalence and severity of RLS in patients with COPD and to investigate the factors potentially associated with RLS.

METHODS

A total of 87 patients with COPD and 110 controls, matched for age and sex, were evaluated regarding the presence and severity of RLS symptoms. A diagnosis of RLS was made according to the criteria of the International RLS Study Group (IRSLSSG), and severity was assessed by the IRLSSG severity scale. Excessive daytime somnolence was assessed using the Epworth sleepiness scale (ESS).

RESULTS

RLS was significantly more frequent in COPD patients than in controls (36.8% vs. 11%; p < 0.001). Compared to controls, COPD patients with RLS showed higher disease severity (mean IRLSSG severity scale score: 20.5 +/- 2.8 for COPD, and 18 +/- 3.5 for controls; p = 0.016) and more pronounced daytime somnolence (mean ESS score: 11.8 +/- 1.1 for COPD, and 8.6 +/- 3.6 for controls; p = 0.009). Moreover, compared to those without RLS, COPD patients with RLS showed increased daytime sleepiness (mean ESS score: 11.8 +/- 1.1 for COPD/RLS, and 7.3 +/- 4 for COPD/non-RLS; p < 0.001) and longer disease duration (11.9 +/- 7 years for COPD/RLS, and 8.7 +/- 6.9 years for COPD/non-RLS; p = 0.045). Multivariate analysis showed that ESS score was the only factor significantly associated with RLS in COPD patients.

CONCLUSIONS

RLS is a frequent cause of disabling sleep disturbance in patients with COPD and should be specifically investigated in these patients.

Prevalence and characteristics of restless legs syndrome in patients with pulmonary hypertension

BACKGROUND

Patients with pulmonary hypertension (PH) have an increased prevalence of risk factors for restless legs syndrome (RLS). We performed a cross-sectional study to determine the prevalence and characteristics of RLS in this population.

METHODS

Patients filled out two questionnaires during a visit: (1) a diagnostic tool for RLS, based on the core clinical features; and (2) a 10-question rating scale used to assess severity. Data were obtained by medical record review with regard to demographics, characteristics of PH and known RLS risk factors.

RESULTS

Restless legs syndrome was found in 43.6% (24 of 55) (mean age +/- SD: 49 +/- 14 years; 41 women, 14 men) of patients and 54% of these had moderate or severe RLS. Patients with RLS were younger but gender differences were not appreciated. Presence of RLS did not correlate with measures of PH severity; however, patients with RLS were more likely to have a better 6-minute walk distance (p = 0.015) and lower BNP level (p = 0.07) and less likely to be WHO Class IV or require oxygen during the 6-minute walk test. Patients with a history of hypothyroidism (67%; p = 0.04) and those on opioids for relief of leg pain (69%) were more likely to have RLS.

CONCLUSIONS

Patients with PH had a very high prevalence of RLS and most had moderate or severe symptoms. RLS was more common in more active patients and those who were hypothyroid or on opioids for relief of leg pain. Patients with PH should be screened for RLS because good treatment options are available.