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

Sleep-related disorders in patients with precapillary pulmonary hypertension

Precapillary pulmonary hypertension (PcPH) is associated with the development of sleep-related disorders and impairment of sleep quality. With growing recognition of the clinical relevance of sleep-related conditions in PcPH, this narrative review seeks to discuss the spectrum of disorders encountered in clinical practice, pathophysiological mechanisms linking PcPH with sleep-related disorders, and potential therapeutic considerations. Current evidence demonstrates a higher prevalence of impaired sleep quality, sleep-disordered breathing, sleep-related hypoxia, and restless leg syndrome in patients with PcPH. These sleep-related disorders could further lead to impairment of quality of life in a patient population with already a high symptom burden. Recent data suggest that sleep-related hypoxia is strongly linked to worse right ventricular function and higher risk of transplantation or death. However, limited studies have investigated the role of oxygen therapy or positive airway pressure therapy improving symptoms or outcomes. Abnormal iron homeostasis is highly prevalent in PcPH and may contribute to the development of restless legs syndrome/periodic limb movement of sleep. To improve sleep management in PcPH, we highlight future research agenda and advocate close collaboration between pulmonary hypertension specialists and sleep physicians.

Increased frequency of the restless legs syndrome in adults with cystic fibrosis

BACKGROUND

Patients with cystic fibrosis (CF) may suffer from iron deficiency which is a known risk factor for the restless legs syndrome (RLS), however, its prevalence has not yet been investigated in these subjects.

PATIENTS AND METHODS

Adult out-patients with CF (n = 39) and healthy volunteers (n = 32) were recruited for this study. A diagnosis of RLS was made based on the diagnostic criteria established by the International Restless Legs Syndrome Study Group (IRLSSG). The IRLSSG rating scale was used to assess the severity of the disease. Furthermore, in the CF group, parameters of iron metabolism were measured in peripheral venous blood samples.

RESULTS

The RLS occurred more frequently in the CF patients than the controls (n = 13/33,3% vs. n = 2/6,3%; p < 0,05). In the CF patients suffering from RLS, the mean score of the IRLSSG rating scale was 17,2 ± 9,4 indicating moderate disease severity. Iron deficiency was present in the majority of the CF patients investigated (n = 33/84,6%), however, serum iron, ferritin and transferrin levels as well as transferrin saturation were similar in those with vs. without RLS.

CONCLUSIONS

The frequency of the RLS is increased in adult patients with CF. On an average, its severity is moderate and it is not related to iron deficiency as evaluated by serum parameters of iron metabolism.

Restless legs syndrome

Restless legs syndrome is a common sensorimotor disorder characterized by an urge to move, and associated with uncomfortable sensations in the legs (limbs). Restless legs syndrome can lead to sleep-onset or sleep-maintenance insomnia, and occasionally excessive daytime sleepiness, all leading to significant morbidity. Brain iron deficiency and dopaminergic neurotransmission abnormalities play a central role in the pathogenesis of this disorder, along with other nondopaminergic systems, although the exact mechanisms are still. Intensive care unit patients are especially vulnerable to have unmasking or exacerbation of restless legs syndrome because of sleep deprivation, circadian rhythm disturbance, immobilization, iron deficiency, and use of multiple medications that can antagonize dopamine.

Poor sleep quality is associated with exercise limitation in precapillary pulmonary hypertension

Background

Patients with precapillary pulmonary hypertension (PH) have been reported to suffer from poor sleep quality, however, if this is related to physical exercise performance has not yet been thoroughly investigated.

Methods

Clinically stable out-patients with idiopathic pulmonary arterial hypertension (IPAH, n = 52) and chronic thromboembolic PH (CTEPH, n = 64) in NYHA classes II and III were prospectively enrolled. 54 healthy volunteers matched for anthropometric variables served as a control group. The Pittsburgh Sleep Quality Index (PSQI) was used to rate subjective sleep quality. In the PH patients, six-minute walk tests (6MWT) were performed to assess exercise capacity.

Results

Poor sleep quality (i.e. a PSQI score > 5) occurred more frequently in PH (IPAH: n = 25 [48.1%], CTEPH: n = 39 [60.9%], controls: n = 10 [18.5%]; p < 0.01 when compared to controls). In addition, poor vs. good sleepers had significantly higher average NYHA class (IPAH: 2.6 ± 0.1 vs. 2.3 ± 0.1, CTEPH: 2.8 ± 0.1 vs. 2.3 ± 0.2; p < 0.01) and shorter 6MWT distances (IPAH: 338 ± 23 vs. 441 ± 29 m, CTEPH: 355 ± 15 vs. 413 ± 26 m; p < 0.05).

Conclusions

Self-reported poor sleep quality is more common in PH than in healthy controls. Furthermore, it is related to reduced physical exercise capacity.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-015-0005-3) contains supplementary material, which is available to authorized users.

Symptom Prevalence, Symptom Severity, and Health-Related Quality of Life Among Young, Middle, and Older Adults With Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a chronic, life threatening illness that affects primarily women. The purpose of this study was to describe the prevalence of PAH symptoms and to determine whether there are differences in symptom severity and HRQOL in PAH symptoms among young, middle, and older adults with PAH. A cross sectional design was utilized. For all the age groups, shortness of breath (SOB) on exertion and fatigue were the two most prevalent symptoms. SOB on exertion had the highest symptom severity scores followed by fatigue for all groups. Symptom severity was significantly different among the groups for palpitations, abdominal swelling and nausea. For components of HRQOL, physical functioning worsened with age. All groups had diminished general health, role physical and vitality levels. There are some differences in symptom prevalence, symptom severity and HRQOL among young, middle and older adults. Awareness of these differences is important for healthcare providers to know and assess overtime. Palliative care should be an integral part of caring for patients with PAH.

The relationship among restless legs syndrome (Willis-Ekbom Disease), hypertension, cardiovascular disease, and cerebrovascular disease

Untreated sleep disorders may contribute to secondary causes of uncontrolled hypertension, cardiovascular disease (CVD), and stroke. Restless legs syndrome, or Willis–Ekbom Disease (RLS/WED), is a common sensorimotor disorder with a circadian rhythmicity defined by an uncontrollable urge to move the legs that worsens during periods of inactivity or at rest in the evening, often resulting in sleep disruptions. Sleep disorders such as insomnia and obstructive sleep apnea (OSA) are established risk factors for increased risk of hypertension and vascular diseases. This literature review outlines the lessons learned from studies demonstrating insomnia and OSA as risk factors for hypertension and vascular diseases to support the epidemiologic and physiologic evidence suggesting a similar increase in hypertension and vascular disease risk due to RLS. Understanding the relationships between RLS and hypertension, CVD, and stroke has important implications for reducing the risks associated with these diseases.

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.

[Frequently occurring sleep disorders]

Some sleep disorders are frequently found in the general population. The most common include restless legs syndrome, insomnia, and sleep apnea. These sleep disorders are well classified and can easily be diagnosed and treated. Since they are risk factors for cardiovascular and psychiatric disorders, early diagnosis and treatment are essential to prevent these sequelae. The impairments caused by these sleep disorders (e.g., due to daytime sleepiness, sleep disruption, or cognitive deficits) can result in a significant reduction in a person's quality of life. The diagnostic and therapeutic recommendations were taken from the S3 guideline "Nonrestorative sleep/sleep disorders" by the German Sleep Society. The levels of evidence were given according to the recommendations of the Oxford Centre for Evidence-based Medicine.

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.

Prevalence of restless legs syndrome in North American and Western European populations: a systematic review

BACKGROUND

Restless legs syndrome (RLS) is a potentially debilitating sleep disorder that affects a significant percentage of North American and European adults. Although standardized RLS diagnostic criteria are now established and widely accepted, reported prevalence estimates have varied widely. In this paper, we review the literature regarding RLS prevalence in North American and Western European adult populations, examine potential sources of variation, briefly discuss the impact of RLS, and offer recommendations for future research.

METHODS

To identify qualifying studies, we searched 6 scientific databases and scanned bibliographies of relevant review papers and all identified articles. Studies including fewer than 300 participants, that did not use any of the 4 standard diagnostic criteria, were published prior to 1995 or targeted clinical populations were excluded.

RESULTS

Thirty-four papers detailing results of large, population-based studies in 16 North American and Western European countries met our inclusion criteria, including 5 multi-country studies (N=69,992 participants) and 29 single country studies (N=163,188 participants); all but one were cross-sectional. Reported general prevalence rates ranged from 4% to 29% of adults, averaging 14.5±8.0% across studies. Reported prevalence averaged higher in primary care populations than in populations derived from random sampling or geographically defined cohorts (19.5±7.9% vs. 12.3±7.2%). Diagnostic and severity criteria differed considerably among studies, as did inclusion criteria, with corresponding variation in prevalence estimates. Prevalence averaged higher in women and older adults; more limited data suggest race/ethnicity, parity, health status, and other factors may also contribute to the observed variation in prevalence. RLS has profound, negative effects on health, well-being, and quality of life, yet detection rates remain low.

CONCLUSIONS

Collectively, these studies indicate that RLS is a common disorder of major clinical and public health significance in the Western industrialized world, affecting between 4% and 29% of adults. The wide variation in reported prevalence likely reflects differences in demographic factors, health status, and other population characteristics; study population source and sampling frame; and inconsistencies in RLS diagnostic criteria and procedures. Prospective studies and corresponding incidence data on RLS are lacking, hindering the evaluation of both causal factors and sequelae.

Clinical outcome after acute ischaemic stroke: the influence of restless legs syndrome

BACKGROUND AND PURPOSE

the objective was to evaluate the presence of Restless Legs Syndrome (RLS) in acute stroke, its association with sleep disturbances and clinical outcome during long-term follow-up.

METHODS

this was a longitudinal study (N = 96, 59 men, mean age 64.0 ± 8.9) of cases with acute ischaemic stroke. Patients were asked about the occurrence of RLS symptoms before the cerebrovascular event. RLS was diagnosed using the criteria established by the International RLS Study Group. Stroke outcome was estimated by the Barthel Index and the modified Rankin Scale. Daytime somnolence (Epworth Sleepiness Scale -ESS > 10), poor sleep quality (Pittsburgh Sleep Quality Index -PSQI > 5) and risk of obstructive sleep apnea (OSA) (Berlin questionnaire) were evaluated.

RESULTS

twelve patients (12.5%) met the diagnostic criteria for RLS. All cases had symptoms of RLS before stroke. However, none of the cases had a previous medical diagnosis of RLS or were on use of specific medication. In only one case, a family history of RLS was found. In all patients, RLS symptoms started after the age of 40 (mean age 64 ± 6.7). Daytime sleepiness (44.8%) and poor quality sleep (62.8%) were present. Patients with RLS (12.5%) presented greater neck circumference (P = 0.04) and worse sleep quality (P = 0.007). Risk of OSA (56.2%) was associated with hypertension [OR = 0.12; CI=0.03-0.42]. Stroke outcome was significantly worse at three and 12 months (ancova, P < 0.005) in patients with RLS, remaining after adjustment for diabetes and body mass index (P < 0.05).

CONCLUSIONS

patients with acute stroke and RLS have worse clinical outcome, at three and 12 months of follow-up.

Restless legs syndrome

Restless legs syndrome (RLS) is characterized by a compelling, often insatiable, need to move the legs, accompanied by unpleasant sensations located mainly in the ankles and calves. Because symptoms are brought on by inactivity, distress intrudes upon everyday, sedentary activities such as plane travel, car rides, and attending school, meetings, or the theatre. Symptoms show a diurnal preference for the evening and night, so disruption of sleep onset or maintenance is particularly common. RLS is associated with both lower ratings of quality of life and higher rates of cardiovascular disease. Four common genetic loci associating to RLS have recently been identified, but the molecular pathways by which they increase risk for RLS have yet to be determined. Both sensory (RLS) and motor (periodic limb movements of sleep) symptoms are responsive to dopaminergic medications, yet clear delineation of dopaminergic pathology has not emerged. Brain iron is reduced in many, but not all, patients with RLS. First-line treatment for RLS includes agents acting at D(2) and D(3) dopamine receptors.