RESUMO
BACKGROUND: Duchenne muscular dystrophy is an X-chromosome-linked genetic disorder (locus Xp21). Involvement of the cardiovascular system is characterized by fibrous degeneration/replacement of myocytes with consequent ventricular hypertrophy and arterial hypertension. OBJECTIVE: To assess, by using 24-hour ambulatory blood pressure monitoring, the behavior of blood pressure variables in children and adolescents with a confirmed diagnosis of Duchenne muscular dystrophy. METHODS: Prospective observational cohort study, which selected 46 patients followed up on an outpatient basis, divided according to age groups. Blood pressure was classified according to the age percentile. The monitoring interpretation includes systolic and diastolic blood pressure means, systolic and diastolic blood pressure loads, and nocturnal dipping. The blood pressure means were calculated for the 24-hour, wakefulness and sleep periods. Nocturnal dipping was defined as a drop in blood pressure means during sleep greater than 10%. The significance level adopted was p < 0.05. RESULTS: Nocturnal dipping for systolic blood pressure was present in 29.9% of the participants. Approximately 53% of them had attenuated nocturnal dipping, and 15%, reverse nocturnal dipping. The age groups of 9-11 years and 6-8 years had the greatest percentage of attenuation, 19.1% and 14.9%, respectively. Regarding diastolic blood pressure, nocturnal dipping was identified in 53.2% of the children, being extreme in 27.7% of those in the age group of 6-11 years. CONCLUSIONS: The early diagnosis of blood pressure changes can allow the appropriate and specific therapy, aimed at increasing the life expectancy of patients with Duchenne muscular dystrophy.
Assuntos
Pressão Sanguínea/fisiologia , Distrofia Muscular de Duchenne/fisiopatologia , Adolescente , Distribuição por Idade , Fatores Etários , Monitorização Ambulatorial da Pressão Arterial , Criança , Pré-Escolar , Humanos , Hipertensão/fisiopatologia , Masculino , Estudos Prospectivos , Valores de Referência , Sono/fisiologia , Estatísticas não Paramétricas , Fatores de TempoRESUMO
Abstract Background: Duchenne muscular dystrophy is an X-chromosome-linked genetic disorder (locus Xp21). Involvement of the cardiovascular system is characterized by fibrous degeneration/replacement of myocytes with consequent ventricular hypertrophy and arterial hypertension. Objective: To assess, by using 24-hour ambulatory blood pressure monitoring, the behavior of blood pressure variables in children and adolescents with a confirmed diagnosis of Duchenne muscular dystrophy. Methods: Prospective observational cohort study, which selected 46 patients followed up on an outpatient basis, divided according to age groups. Blood pressure was classified according to the age percentile. The monitoring interpretation includes systolic and diastolic blood pressure means, systolic and diastolic blood pressure loads, and nocturnal dipping. The blood pressure means were calculated for the 24-hour, wakefulness and sleep periods. Nocturnal dipping was defined as a drop in blood pressure means during sleep greater than 10%. The significance level adopted was p < 0.05. Results: Nocturnal dipping for systolic blood pressure was present in 29.9% of the participants. Approximately 53% of them had attenuated nocturnal dipping, and 15%, reverse nocturnal dipping. The age groups of 9-11 years and 6-8 years had the greatest percentage of attenuation, 19.1% and 14.9%, respectively. Regarding diastolic blood pressure, nocturnal dipping was identified in 53.2% of the children, being extreme in 27.7% of those in the age group of 6-11 years. Conclusions: The early diagnosis of blood pressure changes can allow the appropriate and specific therapy, aimed at increasing the life expectancy of patients with Duchenne muscular dystrophy.
Resumo Fundamento: A distrofia muscular de Duchenne é alteração genética determinada por alteração no braço curto do cromossomo X (locus Xp21). O envolvimento do sistema cardiovascular caracteriza-se por degeneração/substituição fibrótica dos miócitos com consequente hipertrofia ventricular e hipertensão arterial. Objetivo: Avaliar o comportamento de variáveis pressóricas em crianças e adolescentes com diagnóstico confirmado, pela monitorização ambulatorial da pressão arterial por 24 horas. Métodos: Estudo coorte prospectivo e observacional, com seleção de 46 pacientes em acompanhamento ambulatorial, agrupados por faixa etária. A classificação da pressão arterial deu-se conforme o percentil de idade. Na interpretação da monitorização, foram incluídas as médias de pressão arterial sistólica, pressão arterial diastólica, as cargas pressóricas sistólicas e diastólicas e o descenso do sono. As médias pressóricas foram calculadas para o período de 24 horas, vigília e sono. O descenso noturno foi definido como a queda maior que 10% para as médias durante o sono. O nível de significância adotado foi de p < 0,05. Resultados: O descenso noturno para a pressão sistólica esteve presente em 29,9%. Aproximadamente 53% dos participantes apresentaram descenso atenuado e 15%, descenso invertido. As faixas etárias 9 a 11 anos e 6 a 8 anos concentraram o maior percentual de atenuação do descenso, 19,1% e 14,9%, respectivamente. Para a pressão diastólica, o descenso esteve presente em 53,2%, e encontramos 27,7% com descenso acentuado na faixa etária de 6 a 11 anos. Conclusões: Considerando nossos achados, o diagnóstico precoce das anormalidades pressóricas pode ser ferramenta valiosa para a identificação e instalação de terapêutica apropriada visando aumento da sobrevida desses pacientes.