Resposta hemodinamica em individuos normais, avaliada por ecocardiograma, apos sobrecarga oral de glicose

AUTOR(ES)
DATA DE PUBLICAÇÃO

1991

RESUMO

Clinically sound individuals (N = 15), normotensives, white, with ages varying between 20 to 40 years old, with body weights within the ideal range, were submitted to a "IOG" and observed as to their glucemic and insulinemic curves, pulse, blood pressure, and as to echocardiographic hemodynamic parameters. Data was obtained in intervals of 30 minutes of the GTTO, from TO to T120. The analysis of the results showed: 1. The glucemic and insulinemic curves presented a normal distribution. 2. During the first 30 minutes of the GTTO, an early increase of the Cardiac Output and the Fractional Shortening of the left ventricle, accompanying the inicial elevation of the insulinemia. 3. During the first 30 - 60 minutes of the GTTO, a decline df the Systemic Vascular Resistance, the Diastolic Blood Pression and Mean Blood Pressure, frequently accompanied by symptoms of sleepiness and lethargy. This evidence suggests, in accordance to literature, a vasodilating and positive inotropic effect of insulin. 4. After the first 60 minutes of the GTTO, counter regulating phenomenons occurred, that is, increase of Heart Rate, Double Cross Index, normalization of the Systemic Vascular Resistance and the Mean Blood Pressiono This second hemodynamic phase, which can be called .compensatory", is probably related to the activation of the Sympathetic nervous system, due to baroreceptor-reflexes, or due to the characteristic stimulation of insulin on the Central Nervous System and Sympathetic Nervous System. 5. Ali these hemodynamic variations occurred within physiologic and homeostatic limits. The results of this research confirm the cardiovascular effects of insulin demonstrated by various authors through the echocardiographic method, its interaction with the Sympathetic Nervous System and adds the sequence of the phenomenons with time through the GTTO. Clinical implications depend on the greater or smaller capacity of the SNS in counter regulating the vasodilating effects of insulin, principally in diabetics that receive exogenous insulin and frequently present autonomic neuropathy with failure of baroreceptor reflexes. On the other hand, patients with hiperinsulinemia and hiperactivation of the SNS can develop hipertensives status and isquemic cardiopathy.

ASSUNTO(S)

insulina - efeito fisiologico

ACESSO AO ARTIGO

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