The prevalence of restless legs syndrome in Taiwanese adults

Ethnic differences in the prevalence and predictors of restless legs syndrome between Hispanics of Mexican descent and non-Hispanic Whites in San Diego county: a population-based study

STUDY OBJECTIVES

To investigate the prevalence and predictors of RLS in Hispanics of Mexican descent (HMD) and non-Hispanic whites (NHW).

DESIGN

A population-based random digit dialing telephone questionnaire.

SETTING

San Diego County California

PARTICIPANTS

1,754 HMD and 1,913 NHW adults ≥ 18 years of age able to participate in a telephone interview in English or Spanish.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

RLS was defined by the presence of all 4 criteria of the International Restless Legs Study Group. Sleepiness was measured by the Epworth Sleepiness Scale. Acculturation was evaluated using the Short Acculturation Scale for Hispanics. Risk factors for RLS were by self-report. The survey was conducted in the subject's language of choice. RLS prevalence was significantly lower in HMD than in NHW (14.4% vs.18.3%, p = 0.002). High acculturation HMD had a significantly greater RLS prevalence than the low acculturation group (17.4% vs. 12.8%, p = 0.008). Predictors of RLS varied between HMD and NHW. Female gender (OR 1.40, 95% CI 1.04, 1.90, p = 0.027), smoking (OR 1.82, 95% CI 1.27, 2.61, p = 0.001), and acculturation (OR 1.47, 95% CI 1.10, 1.97, p = 0.009) were independent predictors of RLS in HMD, while only older age (OR 1.01, 95% CI 1.0, 1.02) was an independent predictor of RLS for NHW.

CONCLUSION

The prevalence of RLS was significantly lower in HMD than in NHW, and significantly greater in high acculturation HMD. Our data suggest that risk factors for RLS vary by race/ethnicity and acculturation is an independent risk for RLS in HMD.

Strategies for the treatment of restless legs syndrome

Restless legs syndrome (RLS) is a common neurological disorder of unknown etiology that is managed by therapy directed at relieving its symptoms. Treatment of patients with milder symptoms that occur intermittently may be treated with nonpharmacological therapy but when not successful, drug therapy should be chosen based on the timing of the symptoms and the needs of the patient. Patients with moderate to severe RLS typically require daily medication to control their symptoms. Although the dopamine agonists, ropinirole and pramipexole have been the drugs of choice for patients with moderate to severe RLS, drug emergent problems like augmentation may limit their use for long term therapy. Keeping the dopamine agonist dose as low as possible, using longer acting dopamine agonists such as the rotigotine patch and maintaining a high serum ferritin level may help prevent the development of augmentation. The α2δ anticonvulsants may now also be considered as drugs of choice for moderate to severe RLS patients. Opioids should be considered for RLS patients, especially for those who have failed other therapies since they are very effective for severe cases. When monitored appropriately, they can be very safe and durable for long term therapy. They should also be strongly considered for treating patients with augmentation as they are very effective for relieving the worsening symptoms that occur when decreasing or eliminating dopamine agonists.

Risk factors and prevalence rate of restless legs syndrome among pregnant women in Taiwan

BACKGROUND

The goal of this study was to assess the prevalence and clinical correlates of restless legs syndrome (RLS) among pregnant Taiwanese women.

METHODS

We enrolled 461 pregnant women (18-45 years) admitted at Mackay Memorial Hospital for delivery from September 2010 to May 2011. The face-to-face questionnaire used to gather data included assessment of RLS diagnostic criteria, and questions related to RLS.

RESULTS

The overall prevalence rate of RLS among the study participants was 10.4%; 2.8% were categorized as having chronic RLS. Participants without RLS reported higher folate and iron supplement consumption than those with RLS. Multivariate analysis revealed significant associations of RLS with anemia and peptic ulcer disease. Participants with transient RLS during pregnancy reported more regular coffee consumption before pregnancy, and better sleep latency, duration, and efficiency, than those with chronic RLS. Overall, 81.2% of RLS sufferers reported sleep disturbances.

CONCLUSIONS

Our study revealed highly prevalent but poorly recognized RLS among Taiwanese pregnant women. The identification of predictors such as medical comorbidities, and protectors such as folate and iron supplements, is warranted for obstetric RLS. In most cases, symptoms began during the second or third trimester and resolved within a week after delivery. Restricted coffee consumption before pregnancy is encouraged, but further evidence is needed to support this recommendation.

Restless legs syndrome and risk of incident cardiovascular disease in women and men: prospective cohort study

OBJECTIVES

To evaluate the association between restless legs syndrome (RLS) and incident cardiovascular disease (CVD).

DESIGN

Prospective cohort study.

SETTING

Women's Health Study (WHS) and Physicians' Health Study (PHS), USA.

PARTICIPANTS

29 756 female health professionals aged ≥45 years and 19 182 male physicians aged ≥40 years at baseline.

MAIN OUTCOME MEASURES

Main outcome was incidence of major CVD; secondary outcomes were first incidence of myocardial infarction, stroke, death due to CVD or coronary revascularisation.

RESULTS

3487 (11.7%) women and 1373 (7.2%) men met International Restless Legs Study Group criteria for RLS. In the WHS 450 major CVD events occurred and 1064 major CVD events were confirmed in the PHS. In both cohorts, RLS was not associated with increased risk of major CVD, stroke, myocardial infarction, CVD death or coronary revascularisation. After adjustment for major vascular risk factors, the HRs (95% CI) for major CVD were 1.15 (0.88 to 1.50) in women and 1.01 (0.81 to 1.25) in men. Highest multivariable-adjusted HRs were 1.29 (0.91 to 1.82) for total stroke in women and 1.22 (0.87 to 1.70) for CVD death in men. Excluding participants with comorbidities potentially leading to RLS did not substantially change the effect estimates.

CONCLUSIONS

In these large prospective studies of female and male health professionals, RLS was not associated with an increased risk of any incident CVD event. The data do not support the hypothesis that RLS is a marker of increased risk of vascular disease.

Sleep-related movement disorders

Several movement disorders may occur during nocturnal rest disrupting sleep. A part of these complaints is characterized by relatively simple, non-purposeful and usually stereotyped movements. The last version of the International Classification of Sleep Disorders includes these clinical conditions (i.e. restless legs syndrome, periodic limb movement disorder, sleep-related leg cramps, sleep-related bruxism and sleep-related rhythmic movement disorder) under the category entitled sleep-related movement disorders. Moreover, apparently physiological movements (e.g. alternating leg muscle activation and excessive hypnic fragmentary myoclonus) can show a high frequency and severity impairing sleep quality. Clinical and, in specific cases, neurophysiological assessments are required to detect the presence of nocturnal movement complaints. Patients reporting poor sleep due to these abnormal movements should undergo non-pharmacological or pharmacological treatments.

A community-based investigation on restless legs syndrome in a town in China

OBJECTIVE

To assess the prevalence and severity of restless legs syndrome (RLS) in a town in China and to explore potential factors correlated with the severity of the disease.

METHODS

Face-to-face home interviews were conducted among a random sample of 2101 residents in one town in China, all aged 16 years and above. An individual questionnaire was administered to all participants to obtain a diagnosis of RLS and other information. An additional questionnaire was then handed out to each patient diagnosed with RLS to collect information on RLS severity and potential factors correlating with RLS severity.

RESULTS

The prevalence of RLS in the studied population was 7.2%. The prevalence in women was significantly higher than in men and increased with age. Diabetes mellitus, anemia, arthritis, and varicose veins were also associated with RLS. Among the 152 patients, 21.7% were classified as having severe RLS. Multiple correlation analysis reveals that RLS severity was positively correlated with longer disease duration, number of cigarettes smoked per day, and level of work-related physical activity, but negatively correlated with level of leisure time physical activity.

CONCLUSIONS

RLS is common in the studied population. Lifestyle factors may be associated with RLS severity.

Efficacy and safety of pramipexole in chinese patients with restless legs syndrome: results from a multi-center, randomized, double-blind, placebo-controlled trial

BACKGROUND

We performed a six-week study of pramipexole vs. a placebo in Chinese restless legs syndrome patients.

METHODS

Overall, 305 enrolled patients were assigned randomly in a 2:1 ratio to the pramipexole group (N=202) and the placebo group (N=103).

RESULTS

Of 287 patients in the full analysis set, the pramipexole group showed significant improvement compared with the placebo group in the change of their International Restless Legs Syndrome Study Group Rating Scale of Severity (IRLS) total score from baseline to week 6 after adjustment of centers and baseline characters (-15.87±0.66 vs. -11.35±0.92, p<0.0001) and in the proportion of patients who were "much improved" and "very much improved" when measured by Clinical Global Impressions-Improvement (81.9% vs. 54.3%, p<0.0001). At week 6, the IRLS responder rate was 73.8% (pramipexole) and 48.9% (placebo) (p<0.0001) and the patient global impression responder rate was 68.6% (pramipexole) and 43.5% (placebo) (p<0.0001). The proportion of adverse events was 62.9% in the pramipexole group and 43.7% in the placebo group, respectively. No deaths occurred.

CONCLUSION

Pramipexole was effective and well-tolerated in Chinese patients with restless legs syndrome.

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.

Epidemiology of restless legs syndrome: a synthesis of the literature

Restless legs syndrome (RLS) has gained considerable attention in the recent years: nearly 50 community-based studies have been published in the last decade around the world. The development of strict diagnostic criteria in 1995 and their revision in 2003 helped to stimulate research interest on this syndrome. In community-based surveys, RLS has been studied as: 1) a symptom only, 2) a set of symptoms meeting minimal diagnostic criteria of the international restless legs syndrome study group (IRLSSG), 3) meeting minimal criteria accompanied with a specific frequency and/or severity, and 4) a differential diagnosis. In the first case, prevalence estimates in the general adult population ranged from 9.4% to 15%. In the second case, prevalence ranged from 3.9% to 14.3%. When frequency/severity is added, prevalence ranged from 2.2% to 7.9% and when differential diagnosis is applied prevalence estimates are between 1.9% and 4.6%. In all instances, RLS prevalence is higher in women than in men. It also increases with age in European and North American countries but not in Asian countries. Symptoms of anxiety and depression have been consistently associated with RLS. Overall, individuals with RLS have a poorer health than non-RLS but evidence for specific disease associations is mixed. Future epidemiological studies should focus on systematically adding frequency and severity in the definition of the syndrome in order to minimize the inclusion of cases mimicking RLS.

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.