ABSTRACT BACKGROUND: The mechanism of exercise limitation in idiopathic pulmonary arterial hypertension (IPAH) is not fully understood. The role of hemodynamic alterations is well recognized, but mechanical, ventilatory and gasometric factors may also contribute to reduction of exercise capacity in these individuals. OBJECTIVE: To investigate whether there is an association between ventilatory pattern and stress Doppler echocardiography (SDE) variables in IPAH patients. DESIGN AND SETTING: Single-center prospective study conducted in a Brazilian university hospital. METHODS: We included 14 stable IPAH patients and 14 age and sex-matched controls. Volumetric capnography (VCap), spirometry, six-minute walk test and SDE were performed on both the patients and the control subjects. Arterial blood gases were collected only from the patients. The IPAH patients and control subjects were compared with regard to the abovementioned variables. RESULTS: The mean age of the patients was 38.4 years, and 78.6% were women. The patients showed hypocapnia, and in spirometry 42.9% presented forced vital capacity (FVC) below the lower limit of normality. In VCap, IPAH patients had higher respiratory rates (RR) and lower elimination of CO2 in each breath. There was a significant correlation between reduced FVC and the magnitude of increases in tricuspid regurgitation velocity (TRV). In IPAH patients, VCap showed similar tidal volumes and a higher RR, which at least partially explained the hypocapnia. CONCLUSIONS: The patients with IPAH showed hypocapnia, probably related to their higher respiratory rate with preserved tidal volumes; FVC was reduced and this reduction was positively correlated with cardiac output.

FUNDAMENTO: A aterosclerose é uma doença inflamatória e níveis séricos de marcadores inflamatórios, como a interleucina 6 (IL-6), interleucina-18 (IL-18) e proteína C reativa (PCR), são utilizados para avaliação de pacientes em quadros de coronariopatia. No paciente com diabete do tipo 2, a aterosclerose está relacionada a um maior número de eventos como infarto e morte, quando comparado aos pacientes sem diabete. OBJETIVO: Avaliar a resposta inflamatória nos pacientes com diabete e eventos agudos de instabilidade coronariana. MÉTODOS: Selecionamos primariamente dois grupos de pacientes. O primeiro grupo foi composto por pacientes ambulatoriais diabéticos com angina estável (D-SCC) e presença de coronariopatia ao estudo coronariográfico (n = 36). O segundo grupo foi composto por pacientes diabéticos atendidos no pronto-socorro com quadro de síndrome coronariana aguda (D-SCA) sem supradesnivelamento do ST (n = 38). Como controle, foram utilizados pacientes sem diabete com SCA (n = 22) e SCC (n = 16). As concentrações séricas de PCR, IL-6 e IL-18 foram determinadas pelas técnicas de nefelometria (PCR) e ELISA (IL-6 e IL-18). RESULTADOS: Níveis mais elevados de IL-6 foram observados em pacientes com ou sem diabete e SCA em relação ao grupo com SCC. Por sua vez, pacientes com diabete e SCA apresentaram concentrações maiores de PCR em comparação aos outros grupos. Os níveis séricos de IL-18 não diferiram significativamente entre os pacientes estudados. CONCLUSÃO: Os resultados obtidos sugerem uma maior atividade inflamatória no paciente com quadro de instabilidade coronariana. Essa atividade inflamatória, medida pela PCR, parece ser ainda mais intensa no paciente com diabete.

BACKGROUND: Atherosclerosis is an inflammatory disease, and serum levels of inflammatory markers such as interleukin 6 (IL-6), interleukin 18 (IL-18) and C-reactive protein (CRP) are used to evaluate patients with coronary artery disease. In patients with type-2 diabetes, atherosclerosis is related to a larger number of events such as myocardial infarction and death, when compared with patients without diabetes. OBJECTIVE: To evaluate the inflammatory response in patients with diabetes and acute events of coronary instability. METHODS: Two groups of patients were primarily selected. The first group was comprised of diabetic outpatients with stable angina (D-CCS) and presence of coronary artery disease on coronary angiography (n=36). The second group was comprised of diabetic patients seen in the emergency room with acute coronary syndrome (D-ACS) without ST-segment elevation (n=38). Non-diabetic patients with ACS (n=22) and CCS (n=16) comprised the control group. Serum levels of CRP, IL-6 and IL-18 were determined using nephelometry (CRP) and ELISA (IL-6 and IL-18) techniques. RESULTS: Higher serum IL-6 levels were found in diabetic or non-diabetic patients with ACS than in the group with CCS. On the other hand, diabetic patients with ACS had higher CRP levels in comparison with the other groups. Serum IL-18 levels were not significantly different among the patients studied. CONCLUSION: our findings suggest a more intense inflammatory activity in patients with coronary instability. This inflammatory activity, as measured by CRP, seems to be even more intense in diabetic patients.