RESUMO
Increased myocardial lipid delivery is a determinant of myocardial substrate metabolism and function in animal models of type 2 diabetes (T2DM). Sex also has major effects on myocardial metabolism in the human heart. Our aims were to determine whether 1) sex affects the myocardial metabolic response to lipid lowering in T2DM, 2) altering lipid [fatty acid (FA) or triglyceride] delivery to the heart would lower the elevated myocardial lipid metabolism associated with T2DM, and 3) decreasing lipid delivery improves diastolic dysfunction in T2DM. To this end, we studied 78 T2DM patients (43 women) with positron emission tomography, echocardiography, and whole body tracer studies before and 3 mo after randomization to metformin (MET), metformin + rosiglitazone (ROSI), or metformin + Lovaza (LOV). No treatment main effects were found for myocardial substrate metabolism, partly because men and women often had different responses to a given treatment. In men, MET decreased FA clearance, which was linked to increased plasma FA levels, myocardial FA utilization and oxidation, and lower myocardial glucose utilization. In women, ROSI increased FA clearance, thereby decreasing plasma FA levels and myocardial FA utilization. Although LOV did not change triglyceride levels, it improved diastolic function, particularly in men. Group and sex also interacted in determining myocardial glucose uptake. Thus, in T2DM, different therapeutic regimens impact myocardial metabolism and diastolic function in a sex-specific manner. This suggests that sex should be taken into account when designing a patient's diabetes treatment.
Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/uso terapêutico , Ácido Eicosapentaenoico/uso terapêutico , Metabolismo Energético/efeitos dos fármacos , Ácidos Graxos Ômega-3/uso terapêutico , Disparidades nos Níveis de Saúde , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Miocárdio/metabolismo , Tiazóis/uso terapêutico , Função Ventricular Esquerda/efeitos dos fármacos , Análise de Variância , Distribuição de Qui-Quadrado , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/fisiopatologia , Diástole/efeitos dos fármacos , Método Duplo-Cego , Combinação de Medicamentos , Ecocardiografia Doppler , Ácidos Graxos/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Missouri , Tomografia por Emissão de Pósitrons , Recuperação de Função Fisiológica , Fatores Sexuais , Volume Sistólico/efeitos dos fármacos , Fatores de Tempo , Resultado do Tratamento , Triglicerídeos/metabolismo , Pressão Ventricular/efeitos dos fármacosRESUMO
PURPOSE: To test the hypothesis that right enlargement assessed from right ventricular/left ventricular (RV/LV) dimension ratios of computed tomographic (CT) angiograms are equivalent irrespective of whether measured on axial views or reconstructed 4-chamber views. METHODS: RV/LV dimension ratios were calculated from measurements on axial views, manually reconstructed 4-chamber views and computer generated reconstructed 4-chamber views of CT angiograms in 152 patients with PE. RESULTS: Paired readings of the axial view and manually reconstructed 4-chamber view showed agreement with RV/LV > or =1 or RV/LV <1 in 114 of 127 (89.8%). Paired readings also showed agreement in 119 of 127 (93.7%) with axial views and computer generated reconstructed 4-chamber views. The McNemar test showed no statistically significant difference between assessments of RV enlargement (RV/LV > or = 1) with any method. CONCLUSION: Right ventricular enlargement can be determined from axial views on CT angiograms, which are readily and immediately available, without obtaining 4-chamber reconstructed views.