Restless legs syndrome in end-stage renal disease patients undergoing hemodialysis / Síndrome de Piernas Inquietas en enfermedad renal crónica terminal en hemodiálisis

ABSTRACT Restless legs syndrome (RLS) is a frequent complication of hemodialysis that has been associated with poor quality of life and increased risk for complications. Nevertheless, few studies regarding this entity exist in resource-limited settings. Objectives: To determine the prevalence of RLS among Mexican patients on hemodialysis; and compare these patients with a control group of the same population. Methods: We recruited 105 hemodialysis patients. Restless legs syndrome was diagnosed according to the updated criteria set out by the International RLS Study Group. We selected patients who did not meet the criteria, as controls. Results: We found an RLS prevalence of 18%. The RLS patients had a significantly higher prevalence of iron deficiency anemia and uremic pruritus. None of the patients reported RLS symptoms prior to hemodialysis initiation. Conclusions: Restless legs syndrome is common among Mexican patients on hemodialysis. Larger studies are required to address the impact of RLS in hemodialysis patients.

RESUMEN El síndrome de piernas inquietas (SPI) es una complicación de la hemodiálisis que se ha asociado con menor calidad de vida y riesgo aumentado de complicaciones. Sin embargo, existen pocos estudios acerca de esta entidad en escenarios de recursos limitados. Objetivos: Determinar la prevalencia de SPI en pacientes mexicanos en hemodiálisis, y comparar las características con un grupo control de la misma población. Métodos: Reclutamos 105 pacientes en hemodiálisis. El SPI se diagnosticó de acuerdo con los criterios actualizados del grupo de estudio internacional del síndrome de piernas inquietas. Seleccionamos a los pacientes que no cumplieron dichos criterios como controles. Resultados: Encontramos una prevalencia de SPI del 18%. Los pacientes con SPI tenían una prevalencia más alta de anemia ferropénica, y prurito urémico. Ninguno de los pacientes reportó síntomas de SPI previo a iniciar la hemodiálisis. Conclusiones: El SPI es frecuente en pacientes mexicanos en hemodiálisis; se requieren estudios más grandes para evaluar el impacto del síndrome en ésta población.

Restless legs syndrome in Parkinson's disease and increased cardiovascular risk / Síndrome das pernas inquietas em doença de Parkinson e aumento do risco cardiovascular

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.

RESUMO Síndrome das pernas inquietas é um distúrbio comumente encontrado em pacientes com doença de Parkinson (DP), havendo descrições para ambas as condições de prejuízos na transmissão dopaminérgica no sistema nervoso central. Estudos prévios em populações diversas indicam associação entre a presença da síndrome e aumento do risco cardiovascular, não havendo, até o momento, pesquisas consistentes a respeito desta associação em DP. Objetivo: Analisar a influência da síndrome das pernas inquietas no risco cardiovascular em pacientes com DP. Métodos: Foram revisados prontuários de 202 pacientes com diagnóstico de DP e verificada a presença de síndrome das pernas inquietas, comorbidades cardiovasculares, aferições de pressão arterial, lipidograma e escore de Framingham. Resultados: Valores maiores e estatisticamente significativos de colesterol total foram encontrados para o grupo com pernas inquietas (média de 216.6 mg/dL), assim como para colesterol LDL (média de 145 mg/dL). Não foi encontrada diferença estatística entre os demais fatores. Conclusões: Pacientes com DP e síndrome das pernas inquietas têm maior prevalência de dislipidemia do que pacientes sem a síndrome, o que sugere correlação entre síndrome das pernas inquietas e hiperlipidemia. É posto em prova o substrato dopaminérgico como principal na gênese da síndrome, uma vez que, mesmo sob o uso de agonistas dopaminérgicos por ambos os grupos, foi possível observar diferenças entre os estratos. Gerada a hipótese da real interferência do tratamento da síndrome como fator de proteção para o risco cardiovascular.

Clinical correlates of the restless legs syndrome / Correlações clínicas da síndrome das pernas inquietas

OBJECTIVE: To determine the clinical correlates of the restless legs syndrome (RLS) in a Brazilian sleep disorders center. METHODS: We retrospectively studied 118 patients with RLS from January, 2004, to December, 2010. The analyzed variables were: age at disease onset, gender, race, years of school instruction, primary and secondary RLS, and treatment options. RESULTS: Among the studied patients, 83.9% were women with a female/male sex ratio of 5:1. Mean age of the patients at symptom onset ± standard deviation was 41.7±17.9 years-old. The primary RLS was found in 85% of patients. The other 15% remainders consisted of secondary forms, and they were associated with neuropathy, iron deficiency anemia, end-stage renal disease, or Parkinson's disease. Drug therapy for RLS was introduced in 67% of patients. CONCLUSIONS: Most patients presented primary RLS with an early disease onset. Further epidemiological studies are welcomed to provide better information on secondary RLS in Brazil.

OBJETIVO: Determinar as correlações clínicas da síndrome das pernas inquietas (SPI) em um centro brasileiro de distúrbios de sono. MÉTODOS: Foram estudados retrospectivamente 118 pacientes com SPI atendidos entre janeiro de 2004 e dezembro de 2010. As variáveis analisadas compreendiam: idade ao início da doença, sexo, raça, escolaridade, SPI primária e secundária e tratamento da SPI. RESULTADOS: Do total de pacientes estudados, 83,9% eram mulheres e a razão mulher∕homem foi de 5:1. A média de idade dos pacientes ± desvio padrão de quando iniciaram sintomas da SPI foi de 41,7±17,9 anos. Oitenta e cinco por cento dos pacientes apresentaram SPI primária. Os restantes 15% apresentaram a forma secundária, que estava associada à neuropatia periférica, anemia por deficiência de ferro, insuficiência renal crônica e doença de Parkinson. Foi introduzida medicação para SPI em 67% dos pacientes. CONCLUSÕES: A maioria dos pacientes apresentou SPI primária com início precoce da doença. Mais estudos epidemiológicos são necessários para prover informações sobre as causas secundárias de SPI no Brasil.

Restless legs syndrome in subjects with a knee prosthesis: evidence that symptoms are generated in the periphery

OBJECTIVE: There are no data adressing the prevalence of restless legs syndrome in subjects who have knee prosthesis. Therefore, we conducted a cross-sectional survey of subjects who underwent knee prosthesis surgery. METHOD: A total of 107 subjects (30 male, 77 female) were interviewed over the telephone regarding restless legs syndrome symptoms. If the patients exhibited symptoms of the syndrome, we conducted face-to-face interviews. Lastly, a therapeutic test with pramipexole was proposed for each subject. RESULTS: In our cohort, 7 males (23 percent) and 30 females (39 percent) had restless legs syndrome. Of these, 6 males and 23 females were submitted to face-to-face-interview. Of the males, 5 (83 percent) had restless legs after the knee surgeryexclusively in the operated leg- and reported no family restless legs history. One man had a prior case of bilateral restless legs syndrome, a positive family history and claimed exacerbation of symptoms in the operated leg. Among the females, 16 (69 percent) had restless legs prior to surgery. A total of 10 female patients reported bilateral symptoms, with fewer symptoms in the operated leg, while 6 displayed a worse outcome in the operated leg. The 7 females (31 percent) without restless legs prior to surgery and without a family history experienced symptoms only in the operated leg. All subjects responded favorably to the pramipexole therapeutic test. CONCLUSION: Our results suggest that secondary unilateral restless legs syndrome may ensue from knee prosthesis surgery and that the symptoms are generated in the peripheral nervous system.

Restless legs syndrome in patients on chronic hemodialysis in a Brazilian city: frequency, biochemical findings and comorbidities

OBJECTIVE: To evaluate the frequency of restless legs syndrome (RLS) in patients with chronic renal failure (CRF) in Petrópolis, Brazil, and investigate associations between the syndrome and: demographic characteristics, biochemical variables and comorbidities. METHOD: A cross-sectional study in which we interviewed 176 patients on dialytic therapy based on criteria elaborated by the International Restless Legs Syndrome Study Group, and compared data of patients with and without RLS. RESULTS: The frequency was 14.8 percent. There were no significant differences between the two groups in demographic and biochemical variables investigated (iron, creatinine, intact parathyroid hormone, hemoglobin, calcium, phosphate). We found no association between RLS and the most common comorbidities, except for chronic glomerulonephritis (CGN) (OR = 3.84, p < 0.01). CONCLUSION: In the studied population RLS is a common disorder, and is not associated with the investigated biochemical abnormalities. A higher frequency of RLS in subjects with CGN is a finding that needs further investigation