Prospective study of obesity, hypertension, high cholesterol, and risk of restless legs syndrome

The global and regional prevalence of restless legs syndrome among adults: A systematic review and modelling analysis

Background

Restless legs syndrome (RLS) is a prevalent neuro-sensory disorder that impairs quality of life. In this systematic review and modelling study, we estimated the global and regional prevalence of RLS and its associated factors.

Methods

We searched PubMed, Embase, and Medline for population-based studies on RLS prevalence published up to 12 November 2023. The included studies reported prevalence using the International Restless Leg Syndrome Study Group's (IRLSSG) minimal diagnostic criteria without limitations on frequency, duration, or severity. We applied a multilevel multivariable mixed-effects meta-regression to generate the age-specific and sex-specific prevalence of RLS for high socio-demographic index (H-SDI) and low and middle socio-demographic index (LM-SDI) regions. We pooled odds ratios (ORs) for RLS associated factors using random-effects models. Finally, we derived the regional prevalence and cases of RLS based on an associated factor-based model.

Results

From 52 articles across 23 countries, the global RLS prevalence in 2019 was estimated to be 7.12% (95% confidence interval (CI) = 5.15-9.76) among adults 20-79 years of age, equating to 356.07 million (95% CI = 257.61-488.09) affected individuals. Prevalence was similar in H-SDI (7.29%; 95% CI = 5.04-10.41) and LM-SDI (7.10%; 95% CI = 5.16-9.70) regions, with the majority of cases in LM-SDI countries (323.06 million; 90.73%). Europe had the highest (7.60%; 95% CI = 5.44-10.52) and Africa the lowest regional prevalence (6.48%; 95% CI = 4.70-8.87). The Western Pacific Region, meanwhile, had the most cases (111.91 million; 95% CI = 80.93-153.42). Factors positively associated with RLS included advanced age (OR = 1.13; 95% CI = 1.04-1.24), smoking (OR = 1.46; 95% CI = 1.29-1.64), depression (OR = 1.71; 95% CI = 1.26-2.32), and diabetes (OR = 1.54; 95% CI = 1.19-1.97).

Conclusions

A considerable global burden of RLS exists. Effective strategies are needed to increase awareness and optimise resource allocation to address this often-overlooked condition. High-quality epidemiological investigations employing standardised and rigorous criteria for RLS are essential for addressing RLS burden more effectively.

Registration

PROSPERO: CRD42020161860.

The relationship between periodic limb movement during sleep and dyslipidaemia in patients with obstructive sleep apnea

Periodic limb movements during sleep and obstructive sleep apnea are both associated with increased sympathetic tone, and have been proposed as risk factors for heart diseases and, in particular, cardiovascular disease. As sympathetic system activation may lead to dyslipidaemia, periodic limb movements during sleep could be an additional risk factor for cardiovascular disease in patients with obstructive sleep apnea. The aim of the study was to determine whether the presence of periodic limb movements during sleep affects serum lipid levels in obstructive sleep apnea. Total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, non- high-density lipoprotein cholesterol and triglyceride levels were investigated in 4138 patients with obstructive sleep apnea in the European Sleep Apnea Database (ESADA) cohort, divided into those with periodic limb movements during sleep index ≥ 15 per hr (n = 628) and controls (n = 3510). ANCOVA adjusted for age, sex, body mass index, apnea-hypopnea index, alcohol intake, smoking status, diabetes, insomnia and study site was used to assess differences in lipids between periodic limb movements during sleep and controls. Patients with periodic limb movements during sleep (24% female, 54.4 ± 12.1 years, body mass index 31.9 ± 5.8 kg m-2 , apnea-hypopnea index 36.7 ± 25.4 per hr) had higher triglyceride (1.81 ± 1.04 versus 1.69 ± 0.90 mmol L-1 , p = 0.002) and lower high-density lipoprotein cholesterol (1.19 ± 0.34 versus 1.24 ± 0.37 mmol L-1 , p = 0.002) levels, whilst there was no difference in either total cholesterol (4.98 ± 1.10 versus 4.94 ± 1.07 mmol L-1 ), low-density lipoprotein cholesterol (3.04 ± 0.96 versus 2.98 ± 0.98 mmol L-1 ) or non- high-density lipoprotein cholesterol (3.78 ± 1.10 versus 3.70 ± 1.05 mmol L-1 ) concentrations (all p > 0.05). The results remained unchanged after most sensitivity analyses. Patients with obstructive sleep apnea with periodic limb movements during sleep had more prevalent cardiovascular disease (11% versus 6%, p < 0.01). Periodic limb movements during sleep in obstructive sleep apnea is associated with dyslipidaemia independently of important confounders. Our results highlight periodic limb movements during sleep as an additional risk factor for cardiovascular disease in obstructive sleep apnea.

Restless legs syndrome in patients with psoriasis: association with inflammation and sleep quality

BACKGROUND

We aimed to evaluate if psoriasis associated with restless legs syndrome (RLS) due to its close relationship with metabolic disorders.

METHODS

This was a cross-sectional study in which the relationship between RLS and psoriasis was evaluated. Seventy consecutive psoriasis patients and 70 controls without any skin disorder were included in this study. Data including age, gender, body weight, height, and Psoriasis Area Severity Index (PASI) scores were recorded. Diagnosis of RLS was established using International RLS Study Group (IRLSSG) diagnostic criteria. International RLS Rating Scale (IRLSRS) was used to evaluate the severity of symptoms. Each participant completed forms of the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), and the Dermatology Life Quality Index (DLQI).

RESULTS

The RLS frequency in patients with psoriasis was 18.6% vs. 5.7% in the control group (P = 0.018). In psoriasis patients, BMI, DLQI, IRLSRS, hemoglobin, ferritin, CRP, and uric acid levels were significantly higher than those of the controls. In psoriasis patients with RLS, PASI, DLQI, PSQI, IRLSRS scores, CRP level, and BMI were significantly higher, and hemoglobin level was significantly lower relative to the psoriasis patients without RLS. PASI score was the sole independent associate of RLS presence in psoriasis patients.

CONCLUSION

Restless legs syndrome was significantly more common in psoriasis patients, and the presence of RLS was associated with significantly more severe psoriasis, more severe systemic inflammation, lower serum hemoglobin values, worse quality of life, and sleep quality.

The effect of obesity on chronic diseases in USA: a flexible copula approach

We analyze the effect of obesity on the incidence of hypertension, hyperlipidemia and diabetes in USA using a health production theoretical framework along with a bivariate flexible semi-parametric recursive copula model that account for endogeneity. In this approach, the effects of control variables are flexibly determined using additive predictors that allow for a variety of effects. Our findings suggest that there exist a positive and significant effect of obesity on the prevalence of all chronic diseases examined. In particular, after endogeneity is accounted for, the probability of having hypertension, hyperlipidemia and diabetes for obese individuals are, respectively, 35%, 28% and 11% higher than those under the obesity threshold. These findings suggest that lowering obesity rates could lead to significant reductions in the morbidity and mortality associated with these diseases.

Restless legs syndrome

Restless legs syndrome (RLS) is a common sensorimotor disorder characterized by an urge to move that appears during rest or is exacerbated by rest, that occurs in the evening or night and that disappears during movement or is improved by movement. Symptoms vary considerably in age at onset, frequency and severity, with severe forms affecting sleep, quality of life and mood. Patients with RLS often display periodic leg movements during sleep or resting wakefulness. RLS is considered to be a complex condition in which predisposing genetic factors, environmental factors and comorbidities contribute to the expression of the disorder. RLS occurs alone or with comorbidities, for example, iron deficiency and kidney disease, but also with cardiovascular diseases, diabetes mellitus and neurological, rheumatological and respiratory disorders. The pathophysiology is still unclear, with the involvement of brain iron deficiency, dysfunction in the dopaminergic and nociceptive systems and altered adenosine and glutamatergic pathways as hypotheses being investigated. RLS is poorly recognized by physicians and it is accordingly often incorrectly diagnosed and managed. Treatment guidelines recommend initiation of therapy with low doses of dopamine agonists or α₂δ ligands in severe forms. Although dopaminergic treatment is initially highly effective, its long-term use can result in a serious worsening of symptoms known as augmentation. Other treatments include opioids and iron preparations.

Obesity and sleep disturbances: The "chicken or the egg" question

Obesity and sleep disturbances are common conditions in modern societies and accumulating evidence support a close bidirectional causal relationship between these two conditions. Indeed, from one side sleep loss seems to affect energy intake and expenditure through its direct effects on hormone-mediated sensations of satiety and hunger and through the influence on hedonic and psychological aspects of food consumption. Sleep deprived patients have been shown to experiment excessive daytime sleepiness, fatigue, and tiredness that, in a vicious circle, enhances physical inactivity and weight gain. On the other side, obesity is a well-known risk factor for several sleep disorders. This narrative review will discuss the main pathophysiological mechanisms that link sleep loss to obesity and metabolic syndrome with particular attention to the three most common sleep disorders (insomnia, obstructive sleep apnoea syndrome, restless leg syndrome).

New onset of restless legs syndrome in pregnancy in a prospective multiracial cohort: Incidence and risk factors

OBJECTIVE

To determine whether the incidence and risk factors of restless legs syndrome (RLS) in pregnancy differ by race/ethnicity, we estimated relative risks of demographic, socioeconomic, and nutritional factors in association with risk of any incident RLS in pregnancy in a cohort of 2,704 healthy pregnant women without prior RLS.

METHODS

Using data from the multicenter, multiracial National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies-Singletons, we examined the incidence of RLS from early pregnancy to near delivery through up to 6 assessments. Multivariable Poisson models with robust variance were applied to estimate relative risks (RRs).

RESULTS

The cumulative incidence of RLS in pregnancy was 18.1% for all women, 20.3% for White women, 15.4% for Black women, 17.1% for Hispanic women, and 21.1% for Asian women. Among Hispanic women, older age (RR [reference ≤25 years]: 25-35 years, 1.51; 95% confidence interval [CI] 1.05-2.16; ≥35 years, 1.58; 95% CI 0.93-2.68), anemia (RR [reference no]: yes, 2.47; 95% CI 1.31-4.64), and greater total skinfolds of the subscapular and triceps sites, independent of body mass index (RR [reference quartile 1]: quartile 5, 2.54; 95% CI 1.30-4.97; p trend = 0.01) were associated with higher risk of RLS, while multiparity was associated with a lower risk (RR [reference nulliparity]: 0.69; 95% CI 0.50-0.96). In Black women, greater skinfolds and waist circumference were associated with higher risk of pregnancy RLS, although the trends were less clear.

CONCLUSIONS

The incidence of RLS in pregnancy was high and differed by race/ethnicity, which is likely accounted for by differences in other risk factors, such as age, parity, and nutritional factors.

Restless Leg Syndrome and Objectively-Measured Atherosclerosis in the Canadian Longitudinal Study on Aging

BACKGROUND

Previous studies suggest associations between restless leg syndrome (RLS) and atherosclerosis, but these have primarily been based upon subjective atherosclerotic measures.

OBJECTIVE

We evaluated associations between RLS and an objective indicator of atherosclerosis, namely carotid intima-media thickness (cIMT).

METHODS

In this cross-sectional study among 30,097 Canadian Longitudinal Study on Aging (CLSA) participants, we used a four-item questionnaire to screen for probable-RLS. cIMT was measured at the bifurcation of the common carotid artery. Associations were tested with linear regression adjusting for age, sex, ferritin, pulmonary disease, smoking, alcohol, physical activity, anxiety, depression, and other sleep diagnoses.

RESULTS

Among 26,304 included participants, 2047 (7.8%) had probable-RLS. Mean cIMT was higher (0.755 ± 0.17 vs 0.736 ± 0.17, P < 0.001) in those with RLS, even after excluding those without prior atherosclerotic diseases (0.740 ± 0.17 vs 0.723 ± 0.16, P = 0.016).

CONCLUSION

RLS is associated with objective measures of atherosclerosis. © 2020 International Parkinson and Movement Disorder Society.

Increased Blood Pressure Dipping in Restless Legs Syndrome With Rotigotine: A Randomized Trial

OBJECTIVE

The objective of this study was to assess the rotigotine effect on the nocturnal blood pressure (BP) dip by 24-hour ambulatory BP monitoring and on endothelial function in patients with restless legs syndrome (RLS) compared with placebo.

METHODS

In this double-blind, placebo-controlled trial, 76 adult patients with moderate to severe RLS and periodic legs movements in sleep index ≥10/hour were randomized to rotigotine at optimal dose of 3 mg per day or placebo for 6 weeks. A total of 6 patients had a major protocol deviation. Polysomnography, ambulatory BP monitoring, and endothelial function were assessed at baseline and end point. The primary outcome was the between-group difference in the percentage of BP nondipper profiles at end point. The main secondary outcomes were the mean BP dip, periodic legs movements in sleep index, and endothelial function.

RESULTS

Of the 70 patients (age, 59.4 ± 11.40; 43 women) randomized to rotigotine (n = 34) and placebo (n = 36), 66 (33 rotigotine, 33 placebo) completed the study. The percentage of BP nondippers at end point was higher in the placebo than in the rotigotine group (systolic BP, 72.22% vs 47.06%; diastolic BP, 47.22% vs 20.59%; P < 0.05). Mean BP dip at end point was higher in the rotigotine than in the placebo group (systolic BP, 11.24 ± 6.15 vs 6.12 ± 7.98; diastolic BP, 15.12 ± 7.09 vs 9.36 ± 10.23; P < 0.05). Endothelial function was comparable between the groups. No significant safety concerns were reported with similar incidences of adverse events between groups.

CONCLUSION

Rotigotine increased the percentage of BP dipper profiles and the BP dip in patients with RLS. Future studies should assess whether this change is associated with a reduction in the long-term cardiovascular risk in RLS. © 2020 International Parkinson and Movement Disorder Society.

Risk factors for restless legs syndrome in hemodialysis patients in Taiwan: A case-control study

Restless legs syndrome (RLS) increases the risks of cardiovascular disease and death in hemodialysis (HD) patients. Previous studies of risk factors for RLS in HD patients have yielded varying results. We attempted to identify risk factors for RLS in HD patients in Taiwan.This case-control study recruited 59 HD patients with RLS and 353 HD patients without RLS from the largest HD center in Taiwan during the period from April 1, 2015 through August 31, 2015. Demographic and disease characteristics, information from the International Restless Legs Syndrome Study Group (IRLSSG) diagnostic questionnaire, and IRLSSG Severity Scale scores were collected by interview. Clinical laboratory data were abstracted from medical records and then analyzed with logistic regression and Pearson correlation analysis. A P value of less than .05 was considered to indicate statistical significance.A dialysis duration of longer than 5 years (odds ratio [OR] = 2.32; 95% CI = 1.23-4.39; P = .002) and a low high-density lipoprotein cholesterol level (<40 mg/dL in men; <50 mg/dL in women) (OR = 2.73; 95% CI = 1.44-5.15; P = .009) were associated with increased risk of RLS. Among the 59 patients with RLS, 48 (81.3%) had moderate or severe symptoms (IRLSSG Severity Scale >10), and RLS severity was significantly correlated with dialysis duration (r = .26; P = .043).Among HD patients, RLS was more common among those receiving dialysis for longer than 5 years and those with a low serum high-density lipoprotein cholesterol (HDL-C) level.

Evaluation of restless leg syndrome symptoms in patients with lumbosacral canal stenosis comparison with normal population

Introduction: Restless leg syndrome (RLS) is a neurological disorder that causes an irresistible urge to move the legs often associated with an unpleasant sensation. Due to some common presentations between RLS and lumbosacral spinal stenosis, the purpose of this study was to evaluate the symptoms of RLS in the presence of spinal stenosis at the same time as normal populations.Materials and methods: This cross-sectional study examined 45 patients with lumbosacral spinal canal stenosis and 45 normal individuals without a specific disease. Patients aged 50-70 years were included in the study. All the statistical analyses were carried out using SPSS 21.0 software and p < 0.05 was considered statistically significant.Results: 19 subjects (42.22%) in the patient group and eight in the normal group (17.8%) suffered from restless leg syndrome. Multiple linear regression analysis revealed that patients with lumbosacral canal stenosis had almost five score less than others in RLS scale.Conclusion: RLS symptoms were more prominent in lumbosacral canal stenosis patients compared to the normal group. The awareness of its symptoms can help reduce misdiagnosis.

Blood pressure profile and endothelial function in restless legs syndrome

Restless legs syndrome (RLS) is frequently comorbid with hypertension and cardiovascular diseases; however this relationship and underlying mechanisms remain controversial. After clinical evaluation, 84 drug-free patients with primary RLS (53 women; mean age 55.1 ± 12.3 years) and 76 controls (47 women; mean age 52.2 ± 15.3 years) underwent 24-hour ambulatory blood pressure (BP) and polysomnographic monitoring, and peripheral arterial tonometry to assess endothelial function for 61 patients and 69 controls. Hypertension was diagnosed in 11.9% of patients with RLS based on office measurement, and in 46.4% on the 24 h recording, with nighttime hypertension, two times more frequent than daytime hypertension. Periodic limb movement during sleep (PLMS), markers of sleep fragmentation, and systolic and mean BP non-dipping profile were more frequent among patients. BP non-dipping status was associated with older age, later RLS onset and diagnosis, RLS severity and higher sleep fragmentation. The mean 24-hour, daytime and nighttime BP values, the frequency of hypertension and the endothelial function were comparable between groups. However, both systolic and diastolic BP trajectories over a 24-hour period differed between groups. In conclusion, patients with RLS exhibit a 24-hour BP deregulation with increased frequency of systolic non-dipping profiles that could worsen the risk for CVD morbidity and mortality.

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.

Restless legs syndrome and periodic limb movements during sleep in the Multi-Ethnic Study of Atherosclerosis

Study Objectives

To investigate the prevalence of concurrent periodic limb movements during sleep (PLMS) and restless leg syndrome (RLS), as well as the prevalence of PLMS and RLS separately. Additionally, we document these prevalences by age, race/ethnicity, sex, and obesity status.

Methods

Cross-sectional data from 2041 Multi-Ethnic Study of Atherosclerosis (MESA) Sleep ancillary study participants were used. PLMS (>15 periodic limb movements per hour of sleep) was measured by polysomnography. RLS symptoms were assessed using the 2009 International Restless Legs Syndrome Study Group clinical criteria.

Results

The prevalence of RLS with PLMS was 6.7%, RLS alone 16.1%, and PLMS alone 21.2%. RLS with PLMS was prevalent in 7.0% of whites, 4.9% of blacks, 10.1% of Hispanics, and 3.3% of Chinese-Americans. In adjusted models, odds of RLS with PLMS was higher for those older than 67 years versus those younger (odds ratio [OR] [95% confidence interval [CI]] = 1.62 [1.09-2.40]). Relative to white participants, the prevalence of RLS with PLMS tended to be lower among blacks (0.56 [0.32-0.96]). The prevalence of concurrent RLS and PLMS did not statistically differ by sex or obesity status. RLS alone was more common in women.

Conclusions

Approximately 7% of our sample had RLS with PLMS ("electro-clinical RLS"). This condition was more common among older individuals, did not vary by sex, and was less common among blacks. The findings provide some of the first information about the prevalence of concurrent RLS and PLMS in a community-based sample and show distinct sex and race associations for RLS versus electro-clinical RLS.

Comparative Efficacy and Safety of Clonazepam versus Nortriptyline in Restless Leg Syndrome among Forty Plus Women: A Prospective, Open-Label Randomized Study

Aims and Objectives:

The aim of this study is to compare the effect of clonazepam and nortriptyline on rate, frequency, and severity of restless leg syndrome (RLS) in above 40 years women suffering from RLS.

Materials and Methods:

A prospective, randomized, open-label comparative study was conducted at a tertiary care teaching hospital for 1 year. Restless legs syndrome (RLS) diagnosis was based on four essential clinical criteria established by the International RLS Study Group in 2003. Patients were randomized into two groups. Group 1 received tablet clonazepam 0.5 mg bedtime orally daily. Group 2 received tablet nortriptyline 25 mg bedtime orally daily. The primary efficacy endpoints by the International Restless leg Syndrome Scale (IRLS) were evaluated at 0, 4, and 8 weeks. Adverse drug events and safety assessment for vital signs such as blood pressure, pulse, heart rate, waist circumference, and body mass index were compared between two groups.

Results:

Effect on mean IRLSS was statistically more in clonazepam group in comparison to nortriptyline group with comparable results at 8 weeks (P < 0.001), but at 4 weeks, nortriptyline showed less improvement (P < 0.01) versus P < 0.001 in nortriptyline group. Thus, nortriptyline reported relatively more improvement on IRLSS numerically in comparison to clonazepam. Nortriptyline proved to be statistically better in improving the frequency of RLS with comparison to clonazepam, whereas the results were comparable with regard to rate and the severity of RLS. Both the groups were relatively safe and did not produce any change in biochemical parameters and were free from any serious or severe adverse events and overall, both the treatments were well tolerated.

Conclusion:

Both the drugs provided clinically and statistical significant effect on RLS when compared with their respective baselines. However, nortriptyline proved to be statistically better in improving the frequency of RLS in comparison to clonazepam, whereas the results were comparable with regard to rate and the severity of RLS on intergroup comparison. Both the drugs were well tolerated.

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.

Metabolic syndrome and risk of Parkinson disease: A nationwide cohort study

BACKGROUND

The association of metabolic syndrome (MetS) with the development of Parkinson disease (PD) is currently unclear. We sought to determine whether MetS and its components are associated with the risk of incident PD using large-scale cohort data for the whole South Korean population.

METHODS AND FINDINGS

Health checkup data of 17,163,560 individuals aged ≥40 years provided by the National Health Insurance Service (NHIS) of South Korea between January 1, 2009, and December 31, 2012, were included, and participants were followed up until December 31, 2015. The mean follow-up duration was 5.3 years. The hazard ratio (HR) and 95% confidence interval (CI) of PD were estimated using a Cox proportional hazards model adjusted for potential confounders. We identified 44,205 incident PD cases during follow-up. Individuals with MetS (n = 5,848,508) showed an increased risk of PD development compared with individuals without MetS (n = 11,315,052), even after adjusting for potential confounders including age, sex, smoking, alcohol consumption, physical activity, income, body mass index, estimated glomerular filtration rate, and history of stroke (model 3; HR, 95% CI: 1.24, 1.21-1.27). Each MetS component was positively associated with PD risk (HR, 95% CI: 1.13, 1.10-1.16 for abdominal obesity; 1.13, 1.10-1.15 for hypertriglyceridemia; 1.23, 1.20-1.25 for low high-density lipoprotein cholesterol; 1.05, 1.03-1.08 for high blood pressure; 1.21, 1.18-1.23 for hyperglycemia). PD incidence positively correlated with the number of MetS components (log-rank p < 0.001), and we observed a gradual increase in the HR for incident PD with increasing number of components (p < 0.001). A significant interaction between age and MetS on the risk of incident PD was observed (p for interaction < 0.001), and people aged ≥65 years old with MetS showed the highest HR of incident PD of all subgroups compared to those <65 years old without MetS (reference subgroup). Limitations of this study include the possibilities of misdiagnosis of PD and reverse causality.

CONCLUSIONS

Our population-based large-scale cohort study suggests that MetS and its components may be risk factors of PD development.

Higher Prevalence of Hypertension among Individuals with Restless Legs Syndrome: A Meta-Analysis

OBJECTIVE

This study investigated the proposed association between restless legs syndrome (RLS) and the prevalence of hypertension.

METHODS

A meta-analysis was conducted based on searches of the PUBMED, EMBASE, Cochrane Library, and Korean electronic databases. Cohort and cross-sectional studies reporting the incidence of hypertension in individuals with RLS were included. Dichotomous data were pooled to obtain an odds ratio (OR) and 95% confidence interval (CI) for the prevalence of hypertension in individuals with RLS. The main outcome measure of the study was prevalence of hypertension in patients with RLS compared with a control group.

RESULTS

One cohort study and eight cross-sectional studies were included in the meta-analysis. Individuals with RLS had an increased prevalence of hypertension (all studies: OR=1.13, 95% CI=1.04-1.23; cross-sectional studies: OR=1.12, 95% CI=1.01-1.24). However, in subgroup analyses controlling for cardiovascular risk factors, such as diabetes mellitus and dyslipidemia, the differences in the prevalence of hypertension between RLS and control patients were no longer significant.

CONCLUSION

Patients with RLS may have a higher prevalence of hypertension, according to a pooled analysis, but the results remain to be confirmed in well-designed prospective studies.

Periodic limb movements during sleep in stroke/TIA: Prevalence, course, and cardiovascular burden

OBJECTIVE

To define the prevalence, time course, and associated factors of periodic limb movements during sleep (PLMS) in patients with ischemic stroke or TIA.

METHODS

Patients enrolled in the prospective Sleep-Disordered Breathing in Transient Ischemia Attack (TIA)/Ischemic Stroke and Continuous Positive Airway Pressure (CPAP) Treatment Efficacy (SAS-CARE) study underwent a double polysomnographic investigation in the acute and chronic phases after stroke/TIA, together with a MRI brain scan and a 24-hour blood pressure evaluation. The prevalence of PLMS in patients was compared with that in a matched sample of randomly selected healthy controls from the HypnoLaus cohort. One hundred sixty-nine recordings were performed in the acute phase and 191 after 3 months (210 recordings were obtained from the same 105 patients in both phases) and were compared to those of 162 controls.

RESULTS

The mean number of PLMS per hour and the percentage of participants with a PLMS index >10 and >15 per hour were similar between patients and controls. PLMS remained stable from the acute to the chronic phase after stroke. Factors positively associated with PLMS were age, body mass index, and history of hypertension. Blood pressure over 24 hours and the burden of cerebrovascular damage were similar between the groups with PLMS and without PLMS.

CONCLUSIONS

PLMS are equally frequent in patients with stroke/TIA and the general population. The absence of higher blood pressure values and of a greater vascular brain damage found in patients with PLMS compared to those without PLMS might be due to a greater use of antihypertensive medication among patients with PLMS, which corresponds to a higher prevalence of previous diagnosis of hypertension in these patients.

Evaluation of Cardiovascular Risk Factors and Restless Legs Syndrome in Women and Men: A Preliminary Population-Based Study in China

STUDY OBJECTIVES

Many studies have investigated the association between restless legs syndrome (RLS) and cardiovascular risk factors, leading to conflicting results. Therefore, the aim of the current study was to determine whether RLS is associated with cardiovascular risk factors and disease.

METHODS

This cross-sectional study included 5,324 consecutive subjects who visited the Physical Examination Center of The First Affiliated Hospital of Zhengzhou University for their yearly routine physical examination. Participants underwent a face-to-face interview with a neurologist for the assessment of RLS, based on the International Restless Legs Study Group criteria. They also completed a questionnaire related to cardiovascular risk factors and other health-related and demographic information. Logistic regression was used to assess which of the demographic and cardiovascular risk factors increased the odds of RLS. Then, unadjusted and adjusted models were designed to determine whether RLS was associated with increased odds of cardiovascular disease, coronary artery disease, or hypertension.

RESULTS

RLS was observed in 9.2% of the participants. Multivariable logistic regression models, which included the covariates age, sex, body mass index, smoking status, hypercholesterolemia, and Pittsburgh Sleep Quality Index score (dichotomized at 5), demonstrated that female sex (odds ratio [OR]: 2.42, 95% confidence interval [CI]: 1.99-2.95), smoking (OR: 1.96, 95% CI: 1.31-2.92), high cholesterol (OR: 1.30, 95% CI: 1.03-1.64), and PSQI score > 5 (OR: 5.61, 95% CI: 2.14-14.69) are significantly associated with RLS. Additionally, RLS was associated with hypertension, after adjusting for age, sex, body mass index, smoking, hypercholesterolemia, Pittsburgh Sleep Quality Index score > 5, diabetes, anemia, and decreased renal function.

CONCLUSIONS

RLS is associated with the prevalence of hypertension but not with that of cardiovascular disease or coronary artery disease.

Prevalence of restless legs symptoms according to depressive symptoms and depression type: a cross-sectional study

BACKGROUND

Restless legs syndrome is a sensorimotor disorder and it is associated with several other diseases especially mental illnesses.

AIMS

To analyze the relationship between the symptoms of restless legs syndrome and the severity of depressive symptoms and the prevalence of restless legs symptoms in depression subtypes.

METHODS

A cross-sectional study of primary care patients in the Central Finland Hospital District. The prevalence of restless legs symptoms was studied in 706 patients with increased depressive symptoms and 426 controls without a psychiatric diagnosis by using a structured questionnaire. The depressive symptoms were evaluated with the Beck Depression Inventory (BDI) and the psychiatric diagnosis was confirmed by means of a diagnostic interview (Mini-International Neuropsychiatric Interview). The subjects with increased depressive symptoms were divided into three groups (subjects with depressive symptoms without a depression diagnosis, melancholic depression and non-melancholic depression).

RESULTS

In the whole study population, the prevalence of restless legs symptoms increased with the severity of depressive symptoms. The prevalence of restless legs symptoms was highest in the melancholic and non-melancholic depressive patients (52 and 46%, respectively) and then in subjects with depressive symptoms without a depression diagnosis (43.4%), but the prevalence was also substantial (24.6%) in subjects without a psychiatric diagnosis.

CONCLUSIONS

Restless legs symptoms are very common in primary care among subjects with depression, regardless of the depression type. The prevalence of restless legs symptoms increased with increasing severity of depressive symptoms, regardless of the diagnosis. These findings should be considered in clinical evaluation and treatment of patients visiting their physician due to restless legs or depressive symptoms.

Restless legs syndrome in adolescents: relationship with sleep quality, cardiorespiratory fitness and body fat

Objective

The aim of the current study was to investigate the relationship between restless legs syndrome (RLS) and cardiorespiratory fitness, body composition and sleep quality in a sample of adolescents.

Methods

One hundred fifty seven volunteer adolescents (16.6 ± 0.7 yrs) participated in the study. Sleep quality was assessed by the Pittsburg sleep quality index. Cardiorespiratory fitness was assessed by the 20 m shuttle run test and body composition by bioelectrical impedance analysis.

Results

The prevalence of RLS was 5.1%. The adolescents with RLS were found to exhibit significantly higher body fat levels (p=0.019) and poorer sleep quality score (p=0.000) compared with their free-RLS counterparts.

Conclusions

Adolescents with RLS are subjects of higher body fat and impaired sleep quality compared with adolescents without RLS. Early diagnosis and appropriate management of RLS is essential in the adolescents.

Restless legs syndrome and cardiovascular diseases: A case-control study

Objective

The association between restless legs syndrome (RLS), cardiovascular diseases (CVD) and hypertension is inconsistent. This case-control study examined i) the association between primary RLS, CVD and hypertension by taking into account many potential confounders and ii) the influence of RLS duration, severity and treatment, sleep and depressive symptoms on CVD and hypertension in primary RLS.

Methods

A standardized questionnaire to assess the RLS phenotype, history of CVD and hypertension, sleep and depressive symptoms, drug intake and demographic/clinical features was sent to the France-Ekbom Patients Association members. A CVD event was defined as a self-reported history of coronary heart disease, heart failure, arrhythmia or stroke. Hypertension was also self-assessed. Current treatment for hypertension and arrhythmia also defined underlying hypertension and arrhythmia. Controls without RLS and without consanguinity were chosen by the patients.

Results

487 patients with primary RLS (median age 71 years; 67.4% women) and 354 controls (68 years, 47.7% women) were included. Most of the patients (91.7%) were treated for RLS, especially with dopaminergic agonists. The median age of RLS onset was 45 years. CVD and hypertension were associated with RLS in unadjusted association, but not after adjustment for age, sex and body mass index. Patients with RLS and with CVD and/or hypertension were significantly older, with hypercholesterolemia, sleep apnea and older age at RLS and at daily RLS onset compared with patients without CVD and/or hypertension. No significant difference was found for other RLS features, ferritin levels, daytime sleepiness, insomnia and depressive symptoms.

Conclusion

Despite some limitations in the design of this study, we found that most of the treated patients for primary RLS had no association with CVD and hypertension after controlling for key potential confounders. Comorbid CVD or hypertension was associated with cardiovascular risk factors, but not with RLS features except for older age at onset.

Prevalence and associated comorbidities of restless legs syndrome (RLS): Data from a large population-based door-to-door survey on 19176 adults in Tehran, Iran

BACKGROUND

Discrepancies have been reported in the prevalence rate of restless legs syndrome (RLS) among different ethnic groups and geographic populations. Furthermore, there are disagreements on determinant factors and associated comorbidities of RLS. We aimed to estimate prevalence of RLS and investigate its associated comorbid conditions and risk factors in a large population-based door-to-door survey.

METHODS

Following a multistage random sampling from the households lived in 22 urban districts of Tehran, Iran, 19176 participants with ≥30 years of age were recruited. Trained surveyors filled study checklist consisting of baseline characteristics, risk factors and comorbidity profile and the International RLS Study Group (IRLSSG) diagnostic criteria through face-to-face interviews.

RESULTS

In total, 1580 individuals were positively screened for RLS resulting in a standardized prevalence rate of 60.0/1000. There was a gradual increase in RLS prevalence by advancing age, however, sex difference disappeared after adjustment. Parkinsonism [adjusted odds' ratio (adj-OR) = 7.4 (95% CI: 5.3-10.4)], peripheral neuropathy [adj-OR = 3.7 (95% CI: 3.3-4.1)], subjective cognitive impairment (SCI) [adj-OR = 3.1 (95% CI: 2.7-3.4)], acting out dreams [adj-OR = 2.8 (95% CI: 2.5-3.2)], hyposmia [adj-OR = 2.5 (95% CI: 2.2-2.9)], active smoking [adj-OR = 1.5 (95% CI: 1.3-1.9)] and additional number of cardiometabolic diseases associated with higher risk of RLS [adj-OR = 1.6 (95% CI: 1.2-2.3)].

CONCLUSION

Our findings showed that neuro-cognitive co-morbidities such as parkinsonism, peripheral neuropathy, SCI, acting out dreams and hyposmia as well as cardio-metabolic risk factors and diseases were independent determinants of RLS. It is recommended to screen individuals with either these comorbid conditions for RLS or the ones with RLS for the accompanying diseases.

Determination of restless legs syndrome prevalence in children aged 13-16years in the provincial center of Kayseri

OBJECTIVE

This study was conducted to determine the prevalence rate of restless legs syndrome (RLS) and associated factors in adolescents aged 13-16years in the provincial center of Kayseri.

MATERIALS AND METHODS

The study sample included 5720 adolescents who were selected from among 74,421 grade 7-10 students aged 13-16years in the provincial center of Kayseri. Overall, datas from 4792 subjects were included into analysis. Data were collected by using a self reported questionnaire and the Epworth Sleepiness Scale (ESS). The prevalence rate of RLS was determined by questionnaire datas and phone interviews. The effects of age, gender, economical status and body weight on RLS prevalence rate were analyzed. Mean ESS score was calculated. The effect of RLS on academic success, as measured by grade point average, was also assessed. The subjects were stratified as underweight, normal, overweight and obese according to the body mass index and the RLS prevalence rate was compared among groups.

RESULTS

The RLS prevalence rate was determined to be 2.9% among adolescents aged 13-16years in the study group. It was found that gender and economical status had no significant effect on RLS prevalence. Mean age at symptom onset was 11.4years of age. There was a positive family history in 11.3% of subjects. Mean body mass index (BMI) was found to be significantly higher in subjects with RLS (21.5±3.8 vs. 20.5±3.2). Academic success (72.0±11.2 vs. 77.0±12.0) was found to be poorer and daytime sleepiness level, as measured by ESS (11.4±3.9 vs. 6.3±4.0), was found to be higher in subjects with RLS.

CONCLUSION

The RLS prevalence rate was 2.9% in the study sample while gender and economical status had no significant effect on prevalence rate. The RLS, which results in decreased sleep quality and academic success, is an important disorder with a considerable prevalence in the population.

Restless Legs Syndrome in Patients with Hypertension and Diabetes Mellitus

Aim:

The aim of this study was to analyze frequency of restless legs syndrome (RLS) in patients with hypertension and diabetes mellitus.

Patients and Methods:

It was analyzed 120 subjects (from Health Center Živinice/Family Medicine Department) through a survey conducted in the period from March to June 2015, of which 30 (8 men/22 women). Subjects were 30 patients with longtime hypertension (HT)(18 men/12 women), 30 patients with diabetes mellitus (DM) type I or II (9 men/21 women), 30 patients with long standing DM type I or II and HT (12 men /18 women), and 30 control subjects (12 men/18 women). RLS were evaluated by questionnaire - International RLS Study Group Criteria. The average age of patients in the group with HT was 58.70 ± 9.07, in the group with DM 48.43 ± 15.37, and in the group of patients with HT and DM 63.90 ± 7.49 years. In the control group mean age was 52.76 ± 14.83 years. Statistical data were analyzed in Excel and SSPS statistical program.

Results:

RLS was identified in 10 (30%) of those with HT; 7 (21%) in patients with DM, and 10 (30%) in patients with HT+DM. In the control group RLS was verified in 4 (12%) patients. Comparing the results, it was observed significant difference between the HT and the control group (p=0.0012) and HT+ DM and control group (p=0.0012). The frequency of RLS between DM and the control group was not significantly significant (p=0.107).

Conclusion:

RLS is frequent in patients with hypertension (30%), hypertension+ diabetes mellitus (30%), and patients with DM (21%).

Nocturnal systolic blood pressure is increased in restless legs syndrome

Purpose

Restless legs syndrome (RLS) is a frequent sensorimotor disorder characterized by an urge to move the legs, with symptoms appearing during the night and disturbing nocturnal sleep. There is a growing body of evidence that RLS correlates with an increased risk of cardiovascular diseases and hypertension. The aim of this study was to test the hypothesis that patients with RLS have higher blood pressure (BP) during the night than people without RLS.

Methods

We have analyzed polysomnographic (PSG) recordings of 30 patients with RLS and 27 subjects without the sleep disorder. During PSG, beat-to-beat BP measurement was performed.

Results

Patients with RLS have higher nocturnal and sleep-time systolic blood pressure compared to controls (124.4 vs. 116.5 mmHg, p < 0.05; 123.5 vs. 116.1 mmHg, p < 0.05). There was no noticeable dip in the values of nocturnal systolic pressure of patients with RLS.

Conclusions

Our results support the hypothesis that RLS and hypertension are linked. Thus, we believe patients with RLS require close observation with regard to cardiovascular risk factors.

Restless legs syndrome associated with major diseases: A systematic review and new concept

Recent publications on both the genetics and environmental factors of restless legs syndrome (RLS) defined as a clinical disorder suggest that overlapping genetic risk factors may play a role in primary (idiopathic) and secondary (symptomatic) RLS. Following a systematic literature search of RLS associated with comorbidities, we identified an increased prevalence of RLS only in iron deficiency and kidney disease. In cardiovascular disease, arterial hypertension, diabetes, migraine, and Parkinson disease, the methodology of studies was poor, but an association might be possible. There is insufficient evidence for conditions such as anemia (without iron deficiency), chronic obstructive pulmonary disease, multiple sclerosis, headache, stroke, narcolepsy, and ataxias. Based on possible gene-microenvironmental interaction, the classifications primary and secondary RLS may suggest an inappropriate causal relation. We recognize that in some conditions, treatment of the underlying disease should be achieved as far as possible to reduce or eliminate RLS symptoms. RLS might be seen as a continuous spectrum with a major genetic contribution at one end and a major environmental or comorbid disease contribution at the other.

A Four-Year Longitudinal Study on Restless Legs Syndrome in Parkinson Disease

STUDY OBJECTIVES

Restless legs syndrome (RLS) prevalence estimates range from 0% to 52% in Parkinson disease (PD), but the causal relationship between the two disorders is still debated. The present study aims to evaluate RLS prevalence in de novo PD subjects, its incidence during the first 4 years from diagnosis, and possible relationships with clinical, laboratory, and neuroradiological data.

METHODS

One hundred nine newly diagnosed, drug-naïve PD subjects were evaluated at the time of PD diagnosis, and after 2- and 4-years. RLS diagnosis was performed with the RLS Diagnostic Index at each visit. Motor features, additional non-motor symptoms (NMS), and concomitant dopaminergic and nondopaminergic treatments were also gathered. Moreover, at baseline, 65 subjects were randomly selected to undergo a FP-CIT SPECT to study dopamine transporter availability.

RESULTS

RLS prevalence rose from 4.6% at baseline evaluation to 6.5% after 2 years and to 16.3% after 4 years (P = 0.007). A multinomial logistic stepwise regression model selected NMS Questionnaire items more likely to be associated with RLS at diagnosis (insomnia, OR = 15.555; P = 0.040) and with occurrence of RLS during follow-up (dizziness, OR = 1.153; P = 0.022; and daytime sleepiness; OR = 9.557; P = 0.001), as compared to patients without RLS. Older age was more likely associated to increased RLS occurrence during follow-up in a random effect logistic regression model (OR = 1.187; P = 0.036). A multinomial logistic stepwise model found increased dopaminergic transporter availability of affected caudate and putamen to be more likely associated with RLS presence at diagnosis (n = 5; OR = 75.711; P = 0.077), and RLS occurrence during follow-up (n = 16; OR = 12.004; P = 0.059), respectively, as compared to patients without RLS (n = 88).

CONCLUSIONS

RLS is present since PD diagnosis, and increases in prevalence during the course of PD. PD subjects with RLS have higher age at PD onset, more preserved dopaminergic pathways, and worse sleep and cardiovascular disturbances.

Alterations in Lipid and Inositol Metabolisms in Two Dopaminergic Disorders

Background

Serum metabolite profiling can be used to identify pathways involved in the pathogenesis of and potential biomarkers for a given disease. Both restless legs syndrome (RLS) and Parkinson`s disease (PD) represent movement disorders for which currently no blood-based biomarkers are available and whose pathogenesis has not been uncovered conclusively. We performed unbiased serum metabolite profiling in search of signature metabolic changes for both diseases.

Methods

456 metabolites were quantified in serum samples of 1272 general population controls belonging to the KORA cohort, 82 PD cases and 95 RLS cases by liquid-phase chromatography and gas chromatography separation coupled with tandem mass spectrometry. Genetically determined metabotypes were calculated using genome-wide genotyping data for the 1272 general population controls.

Results

After stringent quality control, we identified decreased levels of long-chain (polyunsaturated) fatty acids of individuals with PD compared to both RLS (PD vs. RLS: p = 0.0001 to 5.80x10^-9) and general population controls (PD vs. KORA: p = 6.09x10^-5 to 3.45x10^-32). In RLS, inositol metabolites were increased specifically (RLS vs. KORA: p = 1.35x10^-6 to 3.96x10^-7). The impact of dopaminergic drugs was reflected in changes in the phenylalanine/tyrosine/dopamine metabolism observed in both individuals with RLS and PD.

Conclusions

A first discovery approach using serum metabolite profiling in two dopamine-related movement disorders compared to a large general population sample identified significant alterations in the polyunsaturated fatty acid metabolism in PD and implicated the inositol metabolism in RLS. These results provide a starting point for further studies investigating new perspectives on factors involved in the pathogenesis of the two diseases as well as possible points of therapeutic intervention.

Restless Legs Syndrome and Hypertension in Mexican Women

Background

RLS is a common chronic disorder characterized by an irresistible need to move the lower limbs that affects sleep. Poor sleep has been associated with increased blood pressure (BP). Thus, we evaluated the cross-sectional relationship between RLS and hypertension (HTN) in a large cohort study in Mexico.

Methods

In 2011, 54,925 female participants from the Mexican Teachers' Cohort responded to a four-item questionnaire based on the International Restless Legs Syndrome Study Group's minimal diagnostic criteria. Women also reported diagnosis and treatment of HTN. We used multivariable logistic regression models to estimate prevalence odds ratios (ORs) for HTN, adjusting for lifestyle and dietary factors. We also estimated adjusted prevalence ORs for HTN by frequency of RLS symptoms.

Results

We identified 9,230 cases (17%) of RLS, and the prevalence of HTN was 13.1% among women with RLS and 9.4% among those without RLS. The multivariable-adjusted prevalence OR for HTN comparing women with to those without RLS was 1.18 (95% confidence interval [CI]: 1.10-1.26). Compared to those without RLS, the prevalence OR of HTN in women reporting a symptom frequency of once a month or less was 1.14 (95% CI: 1.00-1.30); among those with symptoms two to four times a month, the OR was 1.17 (95% CI: 1.05-1.30); and for those with symptoms at least two times a week, the OR was 1.22 (95% CI: 1.10-1.35).

Conclusion

We observed an association between RLS and HTN. Future studies should evaluate the impact of treating RLS on BP.