Resumo Pacientes com síndrome metabólica (SM) têm alto risco coronariano e a disfunção da célula beta ou resistência à insulina pode prever um risco adicional de eventos cardiovasculares precoces. Objetivo: Avaliar as alterações glicometabólicas precoces em pacientes com SM, mas sem diagnóstico de diabete tipo

2, apos sindrome coronariana aguda. Metodos: Um total de 114 pacientes foi submetido ao teste oral de tolerância a glicose (TOTG), 1-3 dias da alta hospitalar, apos infarto agudo do miocardio ou angina instavel. Baseado no T OTG, definimos tres grupos de pacientes: tolerância normal a glicose (TNG; n=26), tolerância alterada a glicose (TAG; n=39) ou diabetes mellitus (DM; n=49). O Modelo de Avaliacao da Homeostase (HOMA-IR) foi usado para estimar a resistencia a insulina; a responsividade da celula beta foi avaliada atraves do indice insulinogenico de 30 minutos (∆I30/∆G30). Resultados: Baseado no HOMA-IR, os pacientes com DM eram mais insulino-resistentes do que aqueles com TNG ou T AG (p<0,001). De acordo com o indice insulinogenico, a responsividade da celula beta tambem estava alterada em individuos com DM (p<0,001 vs TNG ou TAG). Conclusao: Altas taxas de alteracoes glicometabolicas foram encontradas apos sindrome coronariana aguda em pacientes com SM. Como essas anormalidades acentuadamente aumentam o risco de desfechos adversos, o T OTG precoce pode ser utilizado em pacientes com SM para identificar aqueles que apresentam maior risco coronariano. (Arq Bras Cardiol 2009;92(2):94-99) Palavras-chave: Resistencia a insulina, sindrome metabolica, sindrome coronariana aguda, diabetes mellitus tipo 2, celulas secretoras de insulina. Summary Background: Patients with metabolic syndrome (MetS) are at high coronary risk and beta-cell dysfunction or insulin resistance might predict an additional risk for early cardiovascular events. Objective: This study aimed to evaluate early glucometabolic alterations in patients with MetS, but without previously known type 2 diabetes, after acute coronary syndrome. Methods: A total of 114 patients were submitted to an oral glucose tolerance test (OGTT) 1-3 days after hospital discharge due to myocardial infarction or unstable angina. Based on the OGTT, we defined three groups of patients: normal glucose tolerance (NGT; n=26), impaired glucose tolerance (IGT; n=39), or diabetes (DM; n=49). The homeostasis model assessment (HOMA-IR) was used to measure insulin resistance; betacell responsiveness was assessed by the insulinogenic index at 30 min (∆I30/∆G30). Results: Based on the HOMA-IR, patients with DM were more insulin-resistant than those with NGT or IGT (p<0.001). According to the insulinogenic index, the beta-cell responsiveness was also impaired in subjects with DM (p<0.001 vs NGT or IGT). Conclusion: High rates of glucometabolic alterations were found after acute coronary syndrome in patients with MetS. As these abnormalities markedly increase the risk for adverse outcomes, early OGTT among MetS patients might be used to identify those at the highest coronary risk. (Arq Bras Cardiol 2009;92(2):89-93)