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.

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.

Hepatitis C virus (HCV) infection is a serious public health problem, since 80% to 85% of HCV carriers develop a persistent infection that can progress into liver cirrhosis and hepatocarcinoma. Considering that the response of hepatitis C patients to combination therapy with interferon and ribavirin depends on HCV characteristics as well as on host features, we made a retrospective analysis of demographic and anthropometrical data and HCV genotype distribution of chronic hepatitis C patients treated in public and private reference centers in Brazil. The medical records of 4,996 patients were reviewed, 81% from public and 19% from private institutions. Patients' median age was 46 years, and there was a higher prevalence of male (62%) and white patients (80%). The analysis of HCV-infecting strains showed a predominance of genotype 1 (64%) over genotypes 2 and 3. The patients' mean weight was 70.6 kg, and 65% of the patients weighed less than 77kg. Overweight and obesity were observed in 37.8% and 13.6% of the patients, respectively. Since a body weight of 75 kg or less has been considered an independent factor that significantly increases the odds of achieving a sustained virological response, the Brazilian population seems to have a more favorable body weight profile to achieve a sustained response than the American and European populations. The finding that 65% of chronic hepatitis C patients have a body weight of 77 kg or less may have a positive pharmacoeconomic impact on the treatment of genotype 1 HCV patients with weight-based doses of peginterferon.

Treatment of chronic hepatitis C is still unspecific. However, there is great expectancy concerning the new pegylated interferons. As there has been much controversy about the best parameters to determine whether treatment is effective, we analyzed several criteria currently used for evaluation, including serum alanine aminotransferase (ALT) normalization, viral load reduction and improvement of hepatic histology.