Racial differences in restless legs symptoms and serum ferritin in an incident dialysis patient cohort

Prevalence of restless legs syndrome in maintenance hemodialysis patients: A systematic review and meta-analysis

BACKGROUND

Restless legs syndrome is associated with quality of life and risk of death in maintenance hemodialysis patients. Although relevant meta-analyses have been conducted, epidemiological studies of restless legs syndrome have increased in recent years.

OBJECTIVE

Our aim was to systematically assess the prevalence of restless legs syndrome in maintenance hemodialysis patients and to evaluate the effect of different geographic regions, genders, study designs, and years of publication on the prevalence of restless legs syndrome.

METHODS

PubMed, Web of Science, EMBASE, The Cochrane Library, China Knowledge Resource Integrated Database, Wanfang Database, Weipu, and Chinese Biomedical Database were searched before March 16, 2023 for the published literature. Two investigators independently performed literature screening, data extraction for eligible studies, and risk of bias assessment. A random-effects model using the stata 15.0 software was used to assess the pooled prevalence of restless legs syndrome.

RESULTS

Fifty-seven articles were included in this meta-analysis, and the pooled prevalence of restless legs syndrome in 12,573 maintenance hemodialysis patients was 24.0 % (95 % CI: 21.0%-26.0 %). Maintenance hemodialysis patients from the Americas region and females had severe symptoms of restless legs syndrome, and the prevalence of restless legs syndrome increased from year to year. The prevalence of restless legs syndrome was higher in maintenance hemodialysis patients in cross-sectional studies and cohort studies compared to case-control studies.

CONCLUSIONS

Maintenance hemodialysis patients have a significantly higher prevalence of restless legs syndrome. These findings may provide some reference value for hospital nursing staff to focus on the management and treatment of restless legs syndrome in maintenance hemodialysis patients.

Nighttime Agitation in Persons with Dementia as a Manifestation of Restless Legs Syndrome

OBJECTIVES

Nighttime agitation or "sundowning" is challenging for clinicians and caregivers to manage in older adults in the dementia stage of Alzheimer's disease (AD-D). Our research previously revealed that nighttime agitation might be a manifestation of restless legs syndrome (RLS). The current study aims to describe the characteristics of older adults with AD-D, nighttime agitation, and RLS, and to evaluate sleep disturbance and iron status in relation to nighttime agitation severity.

DESIGN

An observational study with baseline descriptive and correlational data from a clinical trial.

SETTING AND PARTICIPANTS

Long-term care (n = 69) and independent living (n = 7); age 82.91 ± 9.46 years, with AD-D, nighttime agitation, and RLS.

MEASUREMENTS

Trained observers counted nighttime agitation behaviors. Independent variables were age; cognition measured by the Mini-Mental State Examination; minutes slept from actigraphy; transferrin saturation percentage (TS%) and transferrin from fasting blood samples; and illness severity using the Cumulative Illness Rating Scale for Geriatrics. Bivariate and multivariable linear regression models were generated.

RESULTS

In the multivariable model, sleep minutes (P = .002) and TS% (P = .003) were negatively associated with frequency of nighttime agitation behaviors, and they explained 20% of the variance. Seventy-nine percent received 1 or more medications that worsen RLS symptoms, such as antihistamines and serotonin reuptake inhibitors.

CONCLUSIONS AND IMPLICATIONS

We encourage clinicians to consider nighttime agitation as a manifestation of RLS. Treatment of iron deficiency indicated by low TS% and deprescribing medications that exacerbate RLS may decrease nighttime agitation, improve sleep, and enhance quality of life in older adults with AD-D.

Unraveling the Mysteries of Restless Leg Syndrome

Restless leg syndrome (RLS) or Willis-Ekbom disease (WED) is an under-diagnosed, chronic, and progressive primary sensory-motor disorder. It is characterized by an uncontrollable urge to move the legs due to uncomfortable and sometimes painful sensations, with a diurnal variation. RLS can lead to severe sleep disturbances, a usual cause of consultation. The pathophysiology is known partially, and it is believed that there is an association between the different variants of genetic mutations combined with dopaminergic and brain iron dysregulation, which plays an important role. The data used for this study were extracted from the articles found in the PubMed database that discuss different gene variants, pathophysiology, and various methods of treatment. They also highlight the role of iron in the pathogenesis of RLS as it is required for the synthesis of tyrosine hydroxylase, which is the rate-limiting step for dopamine synthesis. This review article provides a clinically useful overview of RLS in terms of pathophysiological findings, its genetic associations, and therapeutic options by using the currently available literature. Because RLS presents with vague symptoms and shares similarities with many other diseases, it might be overlooked by many physicians resulting in underdiagnosis and under-treatment. While these discoveries provide a breakthrough in understanding the details of RLS, further studies are recommended as these studies are limited to animal models and provide a limited representation of the general population.

Prevalence of restless legs syndrome in chronic kidney disease: a systematic review and meta-analysis of observational studies

INTRODUCTION

Nowadays prevalence of restless legs syndrome (RLS) in chronic kidney disease (CKD) patients was reported in many studies, while the results varied. The aim of our study was to investigate the prevalence of RLS in this population, considering different data collecting measures and diagnostic criteria.

METHODS

MEDLINE, Embase, PsycINFO, and Scopus databases were searched for relevant studies. We limited the analyses to studies using clinical interview or questionnaire for diagnosis. Univariate meta-regression analysis was preformed to assess the effects of the disease-related covariates on prevalence estimates. Comprehensive Meta-Analysis 2.0 was used to perform the meta-analysis.

RESULTS

Fifty-one studies were included in the analysis. Prevalence of RLS was varied by renal function and diagnostic methods. Overall prevalence in CKD populations was 24.2% (95%CI, 20.1-28.7). Pooled prevalence of RLS was higher in patients diagnosed by questionnaire than by clinical interview [26.2% (95%CI, 17.9-36.5) vs. 23.6% (95%CI, 19.6-28.1)]. When grouped by CKD setting, the prevalence was 28.4% (95%CI, 24.6-32.6) in dialysis patients, followed by early stages patients [9.9% (95%CI, 5.4-17.5)], and kidney transplant recipients [6.7% (95%CI, 5.6-7.8)].

CONCLUSIONS

Our meta-analysis suggested that more than one-quarter of CKD sufferers, especially those who were on dialysis, were plagued by RLS. Higher sensitivity of diagnostic criteria in interview may be valuable for timely treatment.

Restless legs syndrome: an underappreciated and distressing problem for haemodialysis patients

Restless legs syndrome is a distressing condition that is more common in patients with end-stage renal failure. Despite the significant impact it has on quality of life and the documented association between restless legs syndrome and increased mortality, limited data regarding the epidemiology of restless legs syndrome in Australian dialysis patients are available. We report a prospective study that assessed the prevalence and factors associated with restless legs syndrome in an in-centre haemodialysis population.

Racial differences in the prevalence of restless legs syndrome in a primary care setting

STUDY OBJECTIVE

To assess the prevalence of restless legs syndrome (RLS) in a primary care clinic and in African American (AA) and non-African American (NAA) racial groups.

METHODS

We examined the prevalence of RLS using 1-on-1 interviews in general medicine clinics. Subjects were interviewed using John Hopkins Telephone Diagnostic Interview. All interviews were conducted by trained physicians.

RESULTS

A total of 190 patients were interviewed: 103 AA (58.3% were female) and 87 NAA (59.8% were female). The overall prevalence of definite RLS was 22.6%. The average age was 53 years (standard deviation, 15) in AA and 50 years (standard deviation, 13) in NAA. Among AA, the diagnosis of RLS was definite in 11.65%, probable in 3.88%, negative in 83.5%, and unknown in 0.97%. Among NAA, patients were either identified as definite RLS (35.63%) or not RLS (64.37%); no patients were diagnosed as probable RLS or unknown. Logistic regression analysis was done to determine whether age, race, and sex were statistically significant predictors of an RLS diagnosis. When accounting for the other variables, the association between NAA and RLS prevalence was statistically significant (P = 0.002).

CONCLUSION

Restless legs syndrome is common among primary care clinic patients. Its prevalence in the NAA population is approximately 3 times higher than in the AA group. We found the association between NAA race and RLS prevalence to be statistically significant. Larger studies are needed to further examine the relation between race and RLS prevalence.

Association of restless legs syndrome variants in Korean patients with restless legs syndrome

STUDY OBJECTIVES

Recent genome-wide association studies (GWAS) for Caucasians identified several allelic variants associated with increased risk of developing restless legs syndrome (RLS), also known as Willis-Ekbom disease. Although the pathogenic mechanisms of RLS are not entirely understood, it is becoming increasingly evident that many diseases such as RLS can be attributed to an epistasis. The study objectives were to evaluate whether the associations of RLS with all loci determined in previous GWAS for Caucasians can be replicated significantly for the Korean population and to elucidate whether an epistasis plays a role in the pathogenesis of RLS.

DESIGN SETTING AND PARTICIPANTS

DNA from 320 patients with RLS and 320 age- and sex-matched controls were genotyped for variants in the RLS loci.

MEASUREMENTS AND RESULTS

A significant association was found for rs3923809 and rs9296249 in BTBD9 (P < 0.0001 and P = 0.001, respectively); the odds ratio (OR) for rs3923809 was 1.61 (P < 0.0001) to 1.88 (P < 0.0001) and the OR for rs9296249 was 1.44 (P = 0.001) to 1.73 (P = 0.002), according to the model of inheritance. The OR for the interaction between rs3923809 in BTBD9 and rs4626664 in PTPRD was 2.05 (P < 0.0001) in the additive model, 1.80 (P = 0.002) in the dominant model and 2.47 (P = 0.004) in the recessive model. There was no significant association between genotypes of all tested single nucleotide polymorphisms and the mean value of serum iron parameters.

CONCLUSIONS

Our results suggest that the role of BTBD9 in the pathogenesis of restless legs syndrome is more universal across populations than previously reported and more efforts should be focused on the role of epistasis in the genetic architecture of restless legs syndrome.